Method and device for control over quality of fluid pumping-out by means of analysis of rate of fluid inflow from rock
SUBSTANCE: method consists in pumping-out fluid from rock with pump assembled in well and in measuring fluid pressure and volume during pumping out by means of sensors arranged in well. Also during pumping out the pumped out volume is registered, rate of fluid inflow is evaluated on the base of measurements of pressure and volume and such rate of fluid pumping out is set that facilitates flowing of fluid practically in one-phase state.
EFFECT: determination of quality and structure of stratum fluid.
24 cl, 20 dwg
The technical field to which the invention relates.
The present invention relates generally to quality control during sampling of formation fluids and, in particular, to the definition according to the rock permeability and fluid mobility from time to issue indicator or criterion of whether the sample fluid in a single phase condition, is whether the flow is laminar, and the level of contamination of mud filtrate is low, which allows to take samples of fluid, with an excellent purity and in single-phase state in which the fluid contained in the rock, which is achieved by use of analysis of fluid flow from the reservoir during the pumping test. Proposed in the invention the method and apparatus also allow you to identify the complications that arise when pumping tests (on the basis of the correlation coefficient for the dependence of pressure on the rate of flow of formation fluids), as well as to optimize the pumping speed by its approval of filtration properties of the reservoir, i.e. the ability of the reservoir to give the contained fluid (including mobility and compressibility of the fluid).
The level of technology
For production of hydrocarbons, such as oil and gas, drilling of wells, resulting in rotation of the drill bit attached to the end of the drill string. Currently significant to what I drilling accounts for directional drilling, i.e. drilling directional and horizontal wells to improve hydrocarbon production and/or extraction from underground reservoirs of additional hydrocarbon reserves. In modern systems, directional drilling is typically used drill string with the layout of the bottom hole Assembly (BHA)at the end of which is set drill bit rotated downhole motor (turbopump downhole motor or mud motor) and/or rotating the drillstring. To measure specific operating parameters related to the drill string, use a number of downhole devices placed in close proximity to the drill bit. Such devices typically include sensors for measuring temperature and pressure in a borehole, the instrument for measuring angles of azimuth and inclination (deviation of the borehole from vertical), as well as instruments for measuring electrical resistivity to determine the presence of hydrocarbons and water. On drill string often impose additional downhole devices, known as equipment logging while drilling (PBC), allowing in the process of conducting drilling operations to determine the geological characteristics of the formation and occurrence of reservoir fluids.
Industrial oil and gas development requires mn is a significant investment. Before the development of the field, operators want to have as much information as possible to assess the profitability of the field. Despite recent advances in data collection during drilling using equipment of measurement while drilling (IPA), it is often necessary to conduct follow-up testing of hydrocarbon reservoirs of the for more data. Therefore, after the completion of drilling hydrocarbon deposits often have to explore other test equipment.
One type of test or formation testing after completion of the drilling of the well is that of the reservoir to cause the flow of fluid, the well is closed, by means of the sampling probe or dual packer take the test fluid in the test volume of lower pressure, then the pressure is allowed to recover to static level. This procedure can be repeated several times at several different depths or in different points of one reservoir and/or in several different reservoirs crossed one well. One of the important aspects of the information collected during the test or tests are based on the nature of the recovery pressure after his pony is possible - create a depression in the reservoir. Based on these data, it is possible to judge rock permeability and the size of the reservoir. In addition, there is a need for the selection of real reservoir fluid samples and their testing to obtain data of the behavior of fluids at the temperature, volume and pressure (PVT), as well as properties of fluids, such as density, viscosity and chemical composition.
To carry out these important tests when using certain systems of drill string need to be retrieved from the wellbore. Then in the hole down another tool or instrument designed for testing or formation testing (test or aprooval layers). The descent of such a device in the wellbore is often performed by cable. Sometimes for the operation of the test device must be used packers for isolating the collector. To control the test layers or transfer receive data currently created a lot of communication. Some of these solutions involve the use of mud pulse downhole telemetry to communicate with the downhole microprocessor located in the test reservoir or associated with him. In another embodiment, can be used cable, the descent from the surface into the borehole, where it is joined with the socket of the electrical connector of the test layer, the result is something between the surface and the test layer is formed electrical connection for transmitting signals. Regardless of the type currently used test equipment and the type of transmission system information costs time and money required to retrieve from the well drill string and run into the well of the other test device, are very high. In addition, if the well has a strong offset from the vertical, the test layers via the technology becomes impossible, because the test device will not be able to pass into the well at a sufficient depth, which lies studied the formation of rocks.
The method and corresponding device for measuring formation pressure and permeability of the rocks described in the patent US 5233866 (Robert Desbrandes). Figure 1 is a reproduction of a figure from this patent, which presents the test method of the reservoir depressions to determine the formation pressure and permeability of the rocks. As shown in figure 1, the method comprises lowering the pressure in the hydraulic line communicating with the wall of the wellbore. At stage 2 by means of the piston increases the volume of the hydraulic lines, thereby reducing it pressure. The rate of pressure reduction is that layer of fluid flowing in the hydraulic line connected to the fluid coming from the hydraulic line, which makes the pressure drops, there is actually linear. To set the base directly to determine the specified permissible variation, uses a process called "building closest straight points. Shown in the drawing, the allowable deviation of the values from the straight line is 2σ. After defining the basic direct volume increase with steady speed. At time t1pressure beyond the limit of 2σand the reason for this deviation is that the pressure in the hydraulic line lies below the reservoir pressure. At time t1create depression is stopped, and in step 3 the pressure is allowed to stabilize. At time t2begins another cycle of reservoir testing depression, which may be the new base line. The test cycle depression is repeated up until the hydraulic line twice will not install some pressure. At time t4the stage 5 is the final test cycle depression to determine the permeability of the reservoir rock. Stage 5 ends at time t5when the pressure in the hydraulic line is restored, reaching the pressure Pm in the well. When aligning the pressure in the hydraulic line and the well, the probability of sticking of the device is reduced. Then the device can be moved to the new location of the test square is one hundred or extracted from the well.
The lack of decisions on patent US 5233866 is that the time required for stabilization of pressure during the "mini-cycles pressure restoration" (VD), make the test layers too long. In the case of low permeability rocks to stabilize the pressure can vary from several tens of minutes to several days. The fact that for the first cycle followed by one or more other cycles, only exacerbates the problem of the duration of the test.
Regardless of the type of equipment used: descent into the well on a cable or measuring the parameters of the reservoir during the drilling process, in the above measurement systems reservoir pressure and permeability pressure is measured by pressure reduction at the site of the wellbore to a value below the expected reservoir pressure that is performed in one step and to a certain value, much less the estimated reservoir pressure, or by continuous pressure reduction with established speed up until due to the receipt in the device formation fluid pressure in the chamber of the instrument stabilizes. Then, at the termination of creating depression, pressure begins to increase and stabilize. To ensure the reliability of the measurement reservoir pressure cycle test depression can be repeated, which in some cases, the loss or distortion of data require re-testing. This method of measurement is associated with a significant amount of time.
The primary application for the present invention, in which a granted patent US 6609569 B2, the proposed device and method of analysis the rate of fluid flow from the reservoir (ASPF), solving the task of eliminating some of the above shortcomings by using the device and method of implementing feedback control to increase the speed tests at reservoir pressure and permeability in comparison with the above-described devices and methods. The increase in the speed of formation testing allows for more tests, giving the actual values of pressure and permeability, which increases the efficiency and safety of operation of the well. In the application Krueger'and offers a device and method that allows you to create a well test volume and steps (step by step) to reduce the pressure in the test volume with variable speed that provides for periodic measurement of pressure by decreasing the test volume. The correction rate of pressure reduction is performed before the pressure is stabilized, eliminating the need multicycle tests. Such apparatus and method based on step-by-step creation of depression significantly reduces the total measurement time, thereby increasing efficiency and without the danger of drilling.
There is a need to determine the mobility of the fluid during pumping in order when selecting samples to ensure quality control samples and the reliability of the assay. Also requires solving the problem of determining the quality and composition of the formation fluid. In addition, the challenge remained to identify complications when pumping related leakage of the packer (hydraulic cuff), the flow of sand and transition of the sample fluid in two-phase state.
Summary of the invention
In the present invention proposes a method and a device designed to perform analysis of the rate of fluid flow from the reservoir (ASPF) at the end of each stroke of the pump stroke of the piston) during testing in order to reliably judge that from rocks taken optimal purity of the sample fluid that are in-phase condition. The present invention provides for the measurement of pressure and piston position of the pump, as well as the calculation of the compressibility and mobility of the formation fluid and the correlation coefficient, showing that the speed, or tempo, pumping corresponds to the ability of the rock to give the contained fluid, i.e. the mobility of the fluid contained in the rock.
The invention provides a building in the process of pumping the graph of the dependence of compressibility is listovogo fluid from time before sampling gives a certain measure of confidence that the wireline fluid contains almost no impurities filtrate. Determination of permeability depending on time also gives an indication of whether the sample of formation fluid in a single phase condition and in conditions of laminar flow. The compressibility of the filtrate is significantly less than the compressibility of the reservoir fluid containing dissolved gas. The invention also provides graphing of pressure dependence of the velocity of the flow with the definition of the correlation coefficient to identify complications of pumping, such as the supply of sand, indicating the rock collector due to too rapid pumping of the fluid. The invention also provides a comparison of the speed pumping with the mobility of the formation fluid to the sample in-phase condition for the least time. Too fast pumping can cause a jump in front of the pump formation fluid in two-phase state (gas and liquid), and too slow increases the duration of pumping, which can cost thousands of additional dollars.
Brief description of drawings
Proposed in the invention, innovation, and the invention is illustrated by illustrated below and attached to the description of the drawings, the cat is where similar components and parts denoted by the same numbers and are shown:
figure 1 - graphical qualitative representation of reservoir testing with measurement of pore pressure in a known manner,
figure 2 is a vertical projection system offshore drilling using the present invention,
figure 3 is a fragment of the drill string, made using the present invention,
figure 4 - diagram of the complete system that implements the present invention,
figure 5 is a vertical projection of a variant of implementation of the present invention with the use of cable technology (test cable),
figure 6 charts the pressure changes depending on time and displacement of the pump, showing the nature of the pressure reduction, a specific theory using for calculation of certain parameters
7 is a graph of pressure depending on time, which shows the initial part of the curve of pressure recovery for a breed with a moderately low permeability,
on Fig graphics describing the method for determining formation pressure using an iterative approximate estimates
figure 9 is a chart describing the method of finding the reservoir pressure using data incomplete recovery pressure
figure 10 is a graph of pressure depending on the speed of the sampling fluid, illyustriruyuthie computing, used in the method of determining reservoir pressure in accordance with the present invention,
figure 11 is a graph illustrating the method proposed in the present invention,
on Fig image is deployed in the borehole probovatel layers on the cable,
on Fig image pump double acting, intended for pumping formation fluid into the wellbore at the formation test to obtain not containing filtrate samples and pumping formation fluid into the receiving tank after obtaining pure samples,
on pig data analysis rate of fluid flow from the reservoir to the three cycles of the pump, pumping the fluid from the rock,
on Fig - schedule of changes in pressure in the pump for pumping formation fluid pressure below the packer (hydraulic cuff), the linear displacement of the piston pump and pumped out by the pump volume for the three cycles of the pump probovatel layers corresponding to the first example pumping formation fluid that has passed without complications,
on Fig - schedule of changes in pressure in the pump depending on the speed of fluid flow from the reservoir to the three cycles of the pump, reflected on Fig and 15; it should be noted that the correlation coefficient (R2) Fig and Fig exceeds 0.99, that is a good indicator of the speed negotiation pumping speed of flow of the PLA is that,
on Fig second example of the dynamics of the process of pumping, a graph illustrating changes in pressure in the pump, the pressure under the packer, the linear displacement of the piston pump and pumped out by the pump volume for the three cycles of the pump probovatel layers corresponding to the second, obviously complicated, example pumping formation fluid,
on Fig - schedule of changes in pressure depending on the speed of fluid flow from the reservoir for all cycles of the pump shown in Fig example, which shows that the correlation coefficient (R2is 0,052, which is an indicator of complications,
on Fig - schedule of changes in pressure depending on the speed of fluid flow from the reservoir to the first two cycles of the pump shown in Fig example, which shows that the correlation coefficient (R2) is 0,9323, which is an indicator of good quality samples up to this point, and
on Fig image sampler that allows you to pump from the reservoir quality of the sample fluid simultaneously measuring the change in mobility/permeability over time, providing a sample in a single-phase state with a low level of contamination of mud filtrate, while the physical characteristics of the received samples correspond to physical characteristics contained in the reservoir fluid.
Described the second embodiment of the invention
Figure 2 shows the rig in one embodiment of the invention. This drawing shows a typical drilling rig 202, which is understandable specialist way performed well 204. Rig 202 has a working column 206, which in this embodiment is a drill string. At the end of the drill string 206 is fixed drill bit 208 for drilling wells 204. The invention may find application with other types of work columns, it is feasible also with cable equipment (cables, ropes, ropes), shown in Fig, columns precast pipes, columns flexible pipes, tubing and other small diameter pipes, such as pipe for lowering into the well under pressure. Rig 202 is installed on the drilling vessel 222, supplied by pipeline 224 connecting the drilling vessel 222 with the sea floor 220. However, for the implementation of the present invention may be adapted to rig any configuration, for example ground installation.
If necessary, drill string 206 may be provided with a downhole motor 210. Part of the drill string 206 is located above the drill bit 208 usual control device, which may have at least one sensor 214 for measuring the conditions of the well characteristics well, chisels and rock collector, known from the prior art. One floor is the heat sensor function 214 is the determination of the direction, azimuth and orientation of the drill string 206 using a measure of the acceleration (accelerometers) or similar transducers. The layout of the bottom hole Assembly (BHA) also contains a test layer 216 made in accordance with the invention and more fully discussed below. At a suitable point in the trigger column 206, for example, on the test layer 216 is telemetry system 212. Telemetry system 212 is used to transfer control signals and data between the surface and the test layer 216.
Figure 3 shows a section of the drill string 206 in which is applied the present invention. This section inside the downhole device is preferably included in the BHA, located near the drill bit (not shown). The instrument comprises a block of data and source 320 energy to provide two-way communication with the surface and supply the deep components. In a preferred embodiment, the downhole device need only start signal from the surface, initiating the process of reservoir testing. In the future, all the functions of the control device are performed by the downhole controller and processor (not shown). The energy source may be a generator driven turbopump downhole motor (drawing not on the azan), or any other suitable power source. There are also stabilizers 308 and 310 for centering section of the drill string 206 with the downhole device and the packers 304 and 306 to isolate part of the annular space. To allow continuous circulation of drilling mud above the packers 304 and 306 at a time, until the drill bit is not rotating, circulating valve is used, preferably located above the upper packer 304. For release of fluid from the test volume between the packers 304 and 306 in the upper annular space use a separate outlet or surge valve (not shown). The release of fluid through this valve reduces the pressure in the test volume that is required for reservoir testing with depression. It is also assumed that the pressure between the packers 304 and 306 can be reduced by sucking the fluid into the device or releasing the fluid into the lower annular space, but in any case, to decrease the pressure you one way or another to increase the volume of medium in the annular space.
In one embodiment of the invention on the test layer 216 between the packers 304 and 306 is retractable sealing Shoe 302, preimages to the borehole wall 4 (Fig 1). The sealing Shoe 302 may be used without a packers 304 and 306, as is sufficiently dense contact with the hole wall can be created by using a single Shoe 302. If the packers 304 and 306 are not used, it is necessary to create efforts, the holding sealing Shoe 302 to the borehole wall 204. The resulting seal creates near the sealing Shoe test volume located within the device and passing to the pump, without the use of volume between the packers.
One of the ways to ensure the integrity of the test volume is more reliable fixation of the drill string 206. For zakalivanie the drill string 206 on the test layer in the design of the drill string 206 can be included managed retractable spacer elements 312 and 314. As shown in the drawing, in this embodiment, the spacer elements 312 and 314 built-in stabilizers 308 and 310. Spacers 312 and 314, which are at the ends should have a rough surface for coupling with the borehole wall, protects the structural elements of a soft material, such as sealing Shoe 302 and the packers 304 and 306, from damage that can be caused by movement of the device. Of particular relevance is the use of spacer elements 312 has on floating drilling rigs, such as installation, shown in figure 2, as caused by motion motion can lead to premature wear of the seals.
Figure 4 schematically illustrates the device shown in figure 3, with the inner and components of deep and surface equipment. For fixing the drill string 206 selectively retractable spacers 312 abuts the wall 204 of the well. Packers 304 and 306, are well known in the art, extend, clinging to the wall 204 of the well. In working condition packers divide the annular space of wells at three sites, rasamma between an upper annular space 402, the secondary annular space 404 and the lower annular space 406. An isolated part of the annular space (or simply an isolated area) 404 bordered by rock layer 218. On the drill string 206 with the possibility of selective or controlled extension in an isolated area 404 has a sliding sealing Shoe 302. As shown in the drawing, through a sliding sealing Shoe 302 passes the hydraulic line that connects the pristine layer of fluid 408 and sensors, such as sensor 424 pressure, creating the hole 420 in the isolated annular space 404. To explore or to take a sample of it is fluid from the rock, it is preferable that the packers 304 and 306 were tightly pressed to the wall 204, and between the wall and the sliding element 302 formed a tight seal. The pressure decrease in an isolated area 404 before entering the sealing Shoe 302 in contact with the hole wall is the inflow of reservoir fluid in from the new zone 404. When such movement of formation fluids, when the sliding element 302 will come into contact with the hole wall, passing through the sealing Shoe 302 hole 420 will be open for receipt of pristine fluid 408. When drilling a directional or horizontal wells, it is highly desirable to control the orientation of the retractable element 302. In the preferred orientation of the retractable element must be directed to the upper part of the borehole wall. To determine the orientation of the retractable element 302 can use the sensor 214, such as accelerometers. Then, the sliding element can be set in a given direction by means of the techniques and not shown on the drawing tools that are well known in the art, such as directional drilling using deflecting sub. Device for drilling, for example, may include a drill string 206, rotating from the ground rotational drive (not shown). For rotation of the column regardless of the drill bit can also be used downhole turbine motor (POS figure 2). Thus, the drill string can be rotated up until the sliding element is not located in a given direction, as measured by the sensor 214. At the time of testing ground rotational drive stopping the pad from sliding the W and drill string 206 ceases to rotate, while the drill bit driven by a downhole turbine motor can continue to rotate.
The management of the test layer preferably is carried out by the downhole controller 418. The controller 418 associated with at least one device 426 control volume system (pump). In a preferred embodiment, the pump 426 is a device with a small piston moving driven by a ball screw and stepper motor or other engine with the smooth control, due to its ability to consistently (in several stages) to change the volume of the system. In addition, the pump 426 may be a screw pump. When using other types of pumps in the system should also include a flow meter. To control the flow of fluid to the pump 426 in the hydraulic line 422 between the pressure sensor 424 and the pump 426 is located the valve 430. Test volume 405 of the device is the amount of space under the exhaust piston pump 426, including the amount of hydraulic lines 422. The pressure sensor is used to measure the pressure in the test volume 404. Here it should be noted that the formation testing can be just as full, if done with the retracted sealing the Shoe 302. In this case the volume of the system includes about the eating of the middle annular space 404. This allows for a "quick test", saving time on the extension and retraction of the Shoe. Sensor 424 is connected to the controller 418, providing the feedback necessary for the operation of a closed-loop control system. Feedback is used to adjust settings, such as pressure limits for subsequent changes in volume. To further reduce the test time in the composition of the downhole controller includes a processor (not separately shown), and to save the data for future analysis and job default settings may be optionally provided by the database and the storage system.
When creating a depression in an isolated area 404, the fluid is diverted into the upper annular space 402 through balancing valve 419. In the channel 427 connecting the pump 426 with balancing valve 419, has an interior valve-valve 432. If you want to take a sample of fluid, instead of switching through balancing valve 419 fluid can be prevented by using internal valves 432, a and 433b in receiving tanks 428, represent optional components of the device. A typical procedure of the fluid sampling involves extracting contained in tanks 428 fluid from the well for analysis.
In the standard version of the instrument designed for testing of formations with low what odvisnosti fluids (with low permeability), the system, in addition to shown on the drawing pump 426 comprises at least one pump (not separately shown). The internal volume of the second pump must be much smaller than that of the main pump 426. It is assumed that the volume of the second pump must be one hundredth of the volume of the main pump. To connect these two pumps to the hydraulic line 422 may be used a conventional t-joint connector with valve-a valve controlled by the downhole controller 418.
In rocks with low permeability, the main pump is used to create the initial depression. The controller switches to the second pump to operate at pressures below the reservoir. The advantage of the second pump with a small internal volume is that the pressure recovery in such pump is faster than the pump a larger volume.
The data in the borehole can be sent to the surface to provide the operator of the drilling rig information about downhole parameters and conditions, or to test the validity of test results. The controller transmits the processed data is located in the well system bi-directional communication link 416. The downhole system 416 transmits data signals in a terrestrial communication system 412. There are a number of known means and methods of data transmission. For the stijene purposes of the present invention will be sufficient for any reasonable system. After the transmitted signal was adopted at the surface of the ground controller and the processor 410 converts the data and transmits the data to the appropriate device 414 output or storage. As described above, the ground controller 410 and terrestrial communication system 412 are also used to send commands to the beginning of test.
Figure 5 shows a variant implementation of the present invention using the device, turn on the cable. In the drawing bore 502 crosses the reservoir 504 rocks containing natural reservoir, which has a gas layers 506, oil, 508 and 510 water. In the well 502 near the rock formation, or formations, 504 is the descent on the cable device 512, supported by the armored cable 514. From the device 512 are spacer elements (paws) 312, if needed, to stabilize the device 512 in the well. The device 512 has two expanding packer 304 and 306, are able to divide the annular space of the borehole 502 with the formation of the upper annular space 402, hermetically isolated secondary annular space 404 and the lower annular space 406. The device 512 is sealing Shoe 302 that can selectively eject. Spacers 312, the packers 304 and 306 and retractable sealing Shoe 302 are almost the same design is the Ktsia, what was described in the Chapter 3 and 4, so here is their detailed description is not repeated.
Telemetry equipment for the option with the use of the device on the cable is a downhole unit 516 bilateral relations associated with ground block 518 two-way communication with one or more conductors 520, passing in an armored cable 514. Ground unit 518 bilateral ties placed in the ground control device, which includes a processor 412 and the output device 414, such as were described in the Chapter 4. The direction of the armored cable 514 when the shutter device in the barrel 502 wells by using the standard cable pulley 522. The composition of the device 512 includes a downhole processor 418 designed for process control reservoir testing using methods, which are discussed below.
Shown in figure 5 variant embodiment of the invention is useful for determining the contact points 538 and 540 between 506 and gas oil 508, as well as between oil 508 and 510 water along the borehole. To illustrate this option, use the outline of the layer 504 imposed schedule 542 variation of pressure with depth. The downhole device 512 includes a pump 426, several sensors 424 and, if necessary, catch basins 428 for uberpro, for example discussed above for option, shown in figure 4. These components are used to measure reservoir pressure at different depths in the well bore 502. Marked on the chart, the pressure values are an indicator of the density of a liquid or gas, which clearly varies from one fluid to the next. Thus, having multiple pressure measurements M1-Mnyou can obtain the necessary data to determine points of contact 538 and 540.
Below are the measurement strategy and methods of calculations to determine the effective mobility (k/μ) fluids in the rock-manifold in accordance with the present invention. The measurement duration is quite small, and the stability of calculation errors is provided for a large range of values of mobility. The initial depression is created at the speed of pumping (corresponding to the speed of retraction of the piston of the pump) from 0.1 to 0.2 cm3/s, which is significantly lower than the corresponding speeds commonly used at the present time. Lower speed pumping reduces the chance of damage to the breed due to the migration of fine particles, reduce temperature changes, caused by expansion of the fluid inertial hydraulic resistance, which is when the permeability measurements of the downhole device may be significant, and so the e allow you to quickly reach steady-state, or stationary inflow of fluid into the sampling probe for any values of mobility, in addition to very low.
At low mobility fluid (less than approximately 2 MJ/SP) achievement of steady-state flow is not required. For these measurements, the compressibility of the fluid is determined by the initial part of the depression, when the pressure in the sampling probe exceeds the formation pressure. The effective mobility of fluids and pressure p* in the remote reservoir is determined by considering the following ways on the initial recovery phase pressure, which eliminates the need for a long final stage of the recovery pressure at which the pressure gradually reaches a constant value.
For higher values of mobility, when the mode of the steady inflow occurs during the depression quickly, the pump piston stop, followed by a rapid pressure recovery. For mobility, equal to 10 MJ/SP, and conditions adopted for the calculations described below as an example (including speed pumping, equal to 0.2 cm3/s)steady-state flow occurs when the depression corresponding to the pressure decrease of about 54 pounds per square inch below the reservoir. The subsequent restoration of the pressure to reservoir pressure plus or minus 0.01 pound per square inch), it only takes about 6 seconds. For the larger values of mobility of the depression on the layer less and the recovery pressure is shorter (both behave inversely proportional to mobility). The mobility can be calculated by the velocity of fluid flow in a steady mode and the difference between the reservoir pressure and the depression. To check the thread on inertial hydraulic resistance can be used multiple speeds pumping. For pumping with lower rates and lower pressure drops may be necessary to Refine the pump.
As shown in figure 4, after the packers 304 and 306 in an operational state, and the pump piston is in its initial position before performing a full stroke to the suction pump 426 is driven, preferably at a constant rate of increase of its working volume, or speed pumping (qus). The sampling probe and the connecting lines (pipelines), leading from it to the pressure sensor and the pump form a volume of fluid in the measuring system, or "system volume", Vsistwhich is supposed to fill in a homogeneous fluid medium, such as drilling mud. Up until the pressure inside the sampler exceeds the formation pressure, and the wall of the collector on the circumference of the wellbore is closed cake, the flow of any fluid in the borehole when the EOS is impossible. Assuming the leakage of fluid through the packer, and the temperature drop caused by the expansion of the fluid when performing work, the pressure in the system according to the pressure sensor is determined by the expansion of the fluid equal to the volume of the pump, increasing during retraction of its piston. If aporsh- the cross-sectional area of the piston pump, x - traveled by the piston, the distance From the compressibility of the fluid and p is the system pressure, rate of pressure drop will depend on the volumetric expansion rate in accordance with equation (1):
Equation (2) shows that during retraction of the piston of the pump volume of the system increases:
and differentiation of equation (2) shows that:
Thus, substitution of the results of solving equation (3) in equation (1) and the conversion will receive:
At a constant compressibility equation (4) can integrate, obtaining the dependence of the pressure in the sampling probe from the scope of the system:
The pressure in the sampling probe can be attributed to the time of calculation of the dependence of the volume of the system from time to time by the equation (2). Conversely, if the compressibility is not constant, its average mn is an increase in the interval between any two values of the volume of the system is determined by the expression:
where the indices 1 and 2 do not necessarily mean measurements, following each other immediately. It should be noted that when creating a depression of the temperature is reduced, the apparent compressibility will be too small. The dramatic increase in compressibility may indicate a complication when pumping, the flow of sand, the degassing of fluid or seepage through the packer or seal between the end of the sampling probe and the wall of the wellbore. In all circumstances, the calculated values of the compressibility will be false whenever the pressure in the sampling probe will be less than the reservoir pressure, resulting in a stream of fluid can flow into the sampling probe, creating the appearance of a noticeable increase in compressibility. However, it should be noted that the actual liquid media compressibility almost invariably increases slightly with decreasing pressure.
Figure 6 shows an example of creating depression with decreasing pressure from the source of absolute hydrostatic pressure in the borehole, 5000 pounds per square inch, up to (and below) the absolute reservoir pressure (p*) 608 comprising 4626,168 a pound per square inch and is calculated on the basis of the following conditions is taken as an example:
is the effective radius of the sampling probe, riequal to 1.27 cm;
- dimensionless geometric coefficient is ecient, G0equal 4,30;
- the initial volume of the system, V0equal 267,0 cm3;
the pumping speed during retraction of the piston, qusconstant and equal to 0.2 cm3/s;
the compressibility, C, is constant and equal to 1×10-5the pound per square inch-1.
In the calculations it was assumed no change of temperature and leakage of fluid into the sampling probe through the seal. The pressure decrease when creating a depression presents depending on time or depending on the increase of the pump during retraction of the piston, which delayed respectively by the lower and upper axes of abscissa of the graph in Fig.6. The initial part of the curve 610 low pressure (above p*) is calculated by the equation (5) using the values of Vsistcalculated by equation (2). A further decrease of pressure passing through the reservoir pressure in the absence of flow in the sampling probe is represented as curve 612 zero mobility. It should be noted that the entire curve is downward pressure with a "zero" movement of the fluid gently curved, due to the constantly increasing volume of the system.
Usually, when the pressure falls below p*, and the rock permeability is greater than zero, contained in the rock, the fluid begins to move in the sampling probe. If the equality p=p* the flow of fluid equal to zero, but with the decrease in the R he gradually increases. In real conditions, you may need some pressure drop to the clay crust has started to flake off, exposing the portion of the wall surface of the wellbore that is within the inner radius of the cuff, or packer, the sampling probe. In this case, the curve describing the change in pressure over time, will not go smoothly in the direction from the curve "zero flow", as shown in Fig.6, and will have a certain inflection. Until the rate of increase of the volume of the system (corresponding to the rate of increase of the working volume of the pump during retraction of its piston) exceeds the intensity, or rate of fluid flow in the sampler, the pressure in the sampling probe will continue to decline. To complement the insufficient inflow of the fluid contained in the volume Vsistexpands. While the inflow of fluid from the rock obeys the Darcy law, its intensity (flow of incoming fluid) will increase, and this increase will be proportional to the differential pressure (p*-p). Ultimately, the speed of the inflow coming from the rocks of the fluid will be compared with the pumping speed, after which the pressure in the sampling probe will remain constant. This mode is known as steady state, or stationary, the influx.
The equation describing the steady flow of fluid, has the following form:
For the conditions given in relation to 6, the pressure drop in depression, provide flow in the steady state, p*-pmouthis 0,5384 a pound per square inch for k/μ=1000 MJ/SP, 5,384 a pound per square inch to 100 MJ/SP, 53,84 a pound per square inch for 10 MJ/SP, etc. At a speed of pumping of 0.1 cm3/with these pressure drops are less than half, and at a speed of pumping 0.4 cm3/s - twice, etc.
As explained below, these depressions at high values of mobility pressure recovery after stopping the pump piston comes very quickly. P value* you can define in a few seconds the pressure value, stabilised after the depression. In case of high mobility of formation fluids (k/μ>50 MJ/SP) pumping speed at the subsequent (-) depression(s)may need to be increased to obtain a sufficient negative pressure differential (p*-p). At lower value of mobility pumping speed should be reduced to ensure that inertial hydraulic resistance (flow-Darcy) is negligible. In these cases, it is desirable to use a total of three different speed pumping.
Calculate the steady state is very desirable for large values of mobility, because of the RA the couple falls compressibility, but the mobility is determined by direct calculation. However, high-quality equipment: first, it is necessary to ensure the constancy of the speed of pumping and the ease of its regulation, and, second, the differential pressure (p*-pmouthshould be small. It is desirable to have small piston driven ball screw and stepper motor to control depression during the approach mode of the steady-state flow at low values of mobility.
Figure 6 shows that pending on the graph the length of time the selection process fluid, characterized curve 614 for mobility of 1.0 MJ/SP and curves for smaller values of mobility, has not reached its steady state. In addition, for the curve 616 corresponding to the mobility of 0.1 MJ/SP and lower deviations from the curve corresponding to zero mobility, barely noticeable. For example, for 10 seconds, the magnitude of the pressure reduction in the mobility of 0.01 MJ/SP only 1,286 pounds on the square inch smaller than in the complete absence of flow. You can assume the possibility of much larger than that of the deviations in pressure due to non-isothermal conditions or minor changes the compressibility of the fluid. The decrease of pressure with respect to R* more than 200-400 lb psi is not recommended, as almost guaranteed significant is nancianne hydraulic resistance (stream, not Darcy), there is a possibility of formation damage due to the migration of fine particles, to avoid violations of the temperature regime becomes much more difficult, it becomes probable, degassing, and increases the power consumed by the pump.
On the length of time when R<R*, and to reach a steady-state flow of fluid there are three indicator speed 1) pumping speed, which characterizes the increase in the volume of the system over time, 2) the speed (intensity) of fluid flow from the reservoir into the sample probe and 3) the rate of expansion of the fluid in the volume of the system, which is equal to the difference between the first two speeds. Assuming that the conditions are isothermal, filtering, breed obeys the law Darcy permeability of the rocks near the end of the sampling probe is not broken, and the viscosity of the fluid is constant, using the following equation linking the three discussed above rate, were calculated are presented on Fig.6 curves 618, 614 and 616 selection of fluid on depression for three values of the mobility of the fluid 10, 1.0 and 0.1 MJ/SP:
in which the flow of fluid from the rock in the sampler at time step n is calculated in accordance with the following expression:
Because to calculate in equation (9) requires a value of pnthat it is necessary to solve equation (8), we used an iterative method. For smaller values of mobility when using pn-1as a first approximate estimate of p convergence of the results was fast. However, for the curve corresponding to 10 MJ/SP, for each time step required a much larger number of iterations, and if the mobility of 100 MJ/SP and above, this procedure has become unstable. You need to use smaller time steps and/or a much larger attenuation (or a method using solvers, not an iterative method).
To initiate the restoration of the pressure piston pump stop (or slow down). When the piston is stopped, the volume of the system remains constant, and the flow of fluid from the reservoir into the sample probe leads to that contained in the volume of system fluid is compressed, respectively, causing a pressure increase. For measurements at high mobility, when calculations are performed only in the regime of steady-state flow, the determination of the compressibility of the fluid is not required. The pressure recovery is used only to determine p*, so to restore the pressure piston pump stops completely. Under the conditions described for 6, cooldown pressure up to R* plus or minus 0.01 f the NT for each square meter is for curves 618, 620 and 622 corresponding to the mobility of 10, 100 and 1000 MD/CP, respectively 6,0, of 0.6 and 0.06 seconds.
For measurements in low mobility when fluid selection mode steady-state flow is not achieved, the pressure recovery is used to determine how p*, and k/μ. However, to carry out measurements throughout the recovery process pressure is not required. It takes a prohibitively long time, because the final segment of the curve recovery pressure is the driving force that brings the pressure to p*tends to zero. In the following part of the description presents a technique that allows to dispense with the measurements on this long recovery phase pressure.
The equation describing the recovery process pressure, assuming constant temperature, permeability, viscosity and compressibility, has the following form:
Rewriting and prointegrirowany this equality, we obtain:
where t0and R0accordingly, the time and pressure in the sampling probe at the beginning of the recovery pressure or at any arbitrary point on the curve of the pressure recovery.
Figure 7 shows the graph corresponding to the initial portion of the curve recovery pressure 630 for mobility 1 MJ/SP, which nachine is the absolute pressure of 4200 lb psi and full restore pressure reached the reservoir pressure p*, equal to 4600 pounds per square inch. This value is calculated from equation (11). In addition to the options shown on this figure, it should be noted that R0=4200 lb on the square inch.
Determination of reservoir pressure p* part-time curve of the pressure recovery can be seen in the example. The table presents data of a hypothetical experiment. The problem is to accurately determine the value of R*, get that any other way is not possible. To obtain R* empirically would require at least 60 seconds instead of 15 seconds, is shown in Fig.7. The only hypothetically known information are system values given for 6, and volume of the system Vsistequal 269,0 cm3. The compressibility, C, is determined using equation (6) according to the data obtained at the beginning of the downward pressure from the hydrostatic pressure in the well.
|These hypothetical recovery pressure reservoir with a moderately low permeability|
|Time t-t0with||Absolute pressure, R, pounds per square inch||Time t-t0with||Absolute pressure, R, pounds per square inch|
The first group of parameters in the right part of equation (11) and the previous logarithmic group can be considered to restore the pressure as the time constant τ. Therefore, by adopting this definition and transforming equation (11), we obtain:
A graph showing the dependence of the left-hand side of equation (12) from (t-t0), is a straight line, for which the tangent of an angle equal to 1/τand cut, clip on the coordinate axis, is equal to zero. On Fig shows graphs constructed according to the data given in the table, using equation (12) under different assumptions, the values of R*. This figure shows that only when the exact value of absolute pore pressure equal to 4600 pounds per square inch, you can get direct 640. In addition to assumptions smaller than the exact value p* (curve 646), the slope of the curve (angle) at an earlier smaller than later. And, nabor is t, for too high of assumptions (curves 642 and 644), the slope of the curve in the earlier sections of more than later.
These observations can be used to create a quick way to find the exact values of R*. First, we calculate the average value of the slope of the curve at an arbitrary early interval of the data presented in the table. The calculation of the tangent of the angle starts at t1and R1and ends at t2and R2. Then calculate the average tangent of the angle of inclination of the later portion of the curve for the later interval data of the specified table. Subscript indices for parameters at the beginning and end of this calculation are respectively 3 and 4. Now divide the tangent of the angle of the early portion of the curve to the tangent of the angle of inclination of the later portion of the curve, having a coefficient R:
Suppose that at the beginning of the early portion of the curve we take from the table the second set of experimental points: time 2,0825 C and absolute pressure of 4,300 pounds per square inch. Suppose also that at the end of the early portion of the curve, the beginning and the end of the later portion of the curve, with subscripts 2, 3 and 4, we take from the table, respectively, 5-th, 9-th and 11-th sets of experimental points. If now we assume that p* is equal to 4700 pounds per square inch, we substitute e and the numbers in the equation (13), and the calculated value of R is equal to 1,5270. Because this value is greater than one, the guess was too high. The results of the evaluation of this and other assumptions relating to the value p* using the same data as discussed above, is presented in the form of the curve 650 figure 9. The exact pressure value p*equal to 4600 pounds per square inch corresponds to a ratio R=1. These calculations can easily be incorporated into the solver, which will quickly lead p* to its exact value, not system charts. By setting the exact value of p*, the mobility is calculated based on the transformation of equation (11) using the compressibility obtained during the initial depression relative to hydrostatic pressure.
In General, for real data when calculating the value of p*, then k/μ avoid using an early interval data recovery pressure. This is the most rapid phase of the recovery process pressure, high differential pressure, has the highest thermal distortion of the data caused by heat compression, and also the greatest likelihood that the flow of incoming fluid will not obey the law Darcy. After determining the values of R* as described above the entire set of data should be presented graphically in accordance with 7. If n is the initial part of this schedule increases the slope of the curve over time, after the curve gradually straightens up, it may be a good indication that the flow of fluid at higher differential pressures is not subject to the law Darcy.
Another method proposed in the present invention, will be explained below with reference to figure 10. Figure 10 presents the relationship between the pressure 602 in the device and the speed of qPP604 inflow of fluid from the reservoir, as well as the impact of the exit velocity of flow above and below certain thresholds. The Darcy law says that the pressure is directly proportional to the velocity of fluid flow in the reservoir. Thus, if we plot the dependence of pressure on the speed of movement of the piston during the pumping, at a constant pressure in the device during movement of the piston with some given velocity of such a graph will be in the form of a straight line. Similarly, a graph of the relationship between the velocity of flow and stable pressure in the area between some lower and upper limits will be in the form of a straight line, usually with a negative slope (m) 606. The tangent of this angle is used to determine the mobility (k/μ) fluid in the rock formation. To obtain the rate of fluid flow from the reservoir equation (8) can be converted as follows:
Equation (14) is true for conditions postanowi what happened inflow, as well as established. The rate of flow from the reservoir qPPcan be calculated by equation (14) for the conditions of unsteady flow, when the parameter is known quite accurately, that allows to define the points to plot, shown in figure 10.
Conditions steady-state flow will simplify equation (14)as (Rn-1-Rn)=0. In the steady state inflow to determine points a straight-line segment of the graph in figure 10 you can use the known parameters of the device and the measured values. On this segment in the equation, you can substitute the pumping rate of qus. Then, using qusin equation (9), we obtain:
In equation (15) m=(p*-pmouth)/qus. The units for k/μ MD/SP, for absolute pressure pnand R* - pounds per square inch, for risee, for qPPcm3/s, for Vusand V0cm3for With - (pound per square inch)-1and for t seconds. Each value of pressure on the straight-line segment represents the settled pressure at a given rate of flow (or speed suction).
In practice, care of the graph away from direct near zero speed of the inflow of reservoir fluid (filtrate) can be an indicator of a penetration device of the drilling fluid (flow rate PR is approximately equal to zero). At high intensities of the inflow of this deviation is usually associated with a mismatch between the inflow to the law Darcy. However, the reservoir pressure can be defined by extending a straight line segment to the intersection with the ordinate axis corresponding to zero speed selection. The calculated value of the reservoir pressure p* should be equal to the measured Plast pressure within a negligible margin of error.
Task hydrostatic reservoir testing is determining the pressure in the rock collector and determining the mobility of the fluid in the collector. Correction of the movement of the piston of the pump to obtain constant values of the measured pressure (zero slope) for a particular method gives the necessary information to determine the pressure and mobility regardless of the method restore pressure to stable level using constant volume.
Certain advantages of this method are the quality control due to the automatic validation of test results by observing a stable recovered pressure, and quality control by comparing the mobility determined in the process of pressure reduction, mobility, defined in the recovery process pressure. In addition, if you are unable to use R. the results of testing, providing a pressure recovery (in case of loss of device integrity or excessive recovery time pressure), the pressure value p*.
Figure 11 presents an example of a graph of change of pressure in the device at the time when you use another method proposed in the present invention. This graph illustrates the method, involving the change of speed of movement of the piston when creating a depression on the basis of the slope of the pressure change over time. Sensor data received at any point in the test, can be used together with equation (14) to generate a plot similar to that shown in figure 10, or typing in the computer-controlled automated solvers. Separate measurements characterizing the steady-state pressure at various speeds the flow, can be used for validation tests.
The implementation proposed in the invention method begins with the deployment of the instrument IPA, similar to the one shown in figure 4, or descent on the cable of the device, similar to the one shown in figure 5. First, the sampling probe device 420 is pressed against the wall of the wellbore, and in test volume 405 is essentially only the drilling fluid, the pressure of which is equal to the hydrostatic pressure is the pressure in the annular space. On a command transmitted from the surface at time 702 begins phase I trials. Next steps it is preferable to make running the downhole controller 418. Using this controller for controlling the suction pump 426 with the piston, the pressure in the test volume is reduced at a constant speed by setting the speed of retraction of the piston of the suction pump to the preset value. For measuring parameters of at least the pressure of the fluid in the unit intervals of time used sensors 424. These intervals set so that in each phase of testing to produce at least two dimensions. Additional benefits can be obtained by measuring the respective sensors system capacity, temperature and/or rate of change of the volume of the system. Phase I determines the compressibility of the fluid in the device, using the above methods of calculation.
Phase II testing begins at time 704, when the pressure in the device drops below the reservoir pressure p*. The slope of the pressure change, due to the early receipt of the formation fluid in the test volume. This change of angle is determined using a downhole processor that calculates the angle of the curve based on the measurement results obtained for two period of time in pre is Elah one phase. If the rate of absorption of fluid maintained at a constant level, the pressure in the instrument sought would be set at some level, lower R*.
At a given point in time 706, the absorption rate increases, taking the test in phase III. Due to the increased speed of the suction pressure in the device is reduced. With decreasing pressure the rate of flow of formation fluids into the device increases. The pressure in the apparatus will tend to be smaller than that to which it sought in phase II, because the absorption rate in phase III than in phase II. When the results of interval measurements show that the pressure in the device is approaching stabilization, the absorption rate at time 708 again reduce the starting phase IV trials.
Then the absorption can be slowed down or stopped so that the pressure in the device began to grow. When the pressure starts to rise, the slope will change sign, and this change gives rise to phase V (point 710), then the absorption rate increases to stabilize the pressure. About stabilizing pressure is judged by the fact that the results of measurement of the pressure curve pressure becomes zero. Then the speed of retraction of the piston is reduced, allowing the pressure in the phase VI, starting at time 712, grow as long as it is not the camera is literoitca again. After the pressure has been established, phase VII, starting at time 714, the piston of the suction pump is stopped and the pressure in the device is allowed to grow as long as it is not located at the level of the reservoir pressure pPL. After this test is completed, the controller aligns the pressure in the test volume 716 of the hydrostatic pressure in the annular space. Now the device can be set in the retracted position and move to a new location or removed from the well.
The value of the established pressure obtained in phase V (starting at point 710) and phase VI (beginning at point 712), and the corresponding speed of the piston is used by the downhole processor to build a curve similar to that shown in figure 10. On the discrete results of the measurements, the processor calculates the pressure p*. Then the calculated value of R* is compared with the measured reservoir pressure pPLreceived by the device in phase VII (the starting point 714) test. This comparison is performed to check the validity of the values measured reservoir pressure pPLthat allows you to do without separate control tests.
Other ways of carrying out similar tests with one or more of the techniques discussed above method are also considered under atentie claims to this invention. Continuing to consider 11, it should be noted that the implementation of the method in another embodiment, including phase I-IV, and then phase VII. This option is useful when testing the rock layers of moderate permeability, when it is necessary to measure formation pressure. In this embodiment, the profile of the percolation phase IV is usually slightly different from those shown. Phase VII begins when the measurement results show that the slope of the curve of pressure was almost zero (cut 709). Before moving the device in this embodiment is also necessary operation 716 equalize the pressure.
Another variant implementation of the present invention provides for the conduct of phase I (beginning at point 702), phase II (beginning at point 704), phase VI (beginning at point 712) and phase VII (starting at point 714), and operation 716 adjustment pressures. This variant of the method used in the formations of very low permeability or loss of tightness of the sampling probe. In phase II, the deviation of the curve is not as pronounced as shown in the graph, so straight section 703 of phase I, obviously, should go significantly below the reservoir pressure pPL.
On Fig shown aprooval layers on the cable that is deployed in the borehole without the use of packers. Fig illustrates the implementation of the present invention from the point of the vision is the device of the instrument or tool for formation testing, also called probowalem layers. On Fig given image probovatel layers, taken from patent US 5303775 (Michaels, and others), the content of which in full is included in this description by reference. In the patent US 5303775 the proposed method and the device used in the selection of the sample contained in the rock of the fluid in the undisturbed phase condition using downhole probovatel reservoirs for delivery of this sample in a sealed receiving tank in the laboratory complex. The pressure in one or more placed in the tool receiving tanks for sampling the equalized with the fluid pressure in the borehole at the level of the studied reservoir, and these tanks are filled with samples of formation fluids so that during filling of the receiving tank pressure formation fluid is maintained within a specified interval greater than the saturation pressure of the sample fluid. Receiving tank contains located inside the free-floating piston, which divides the receiving tank to the chamber for placing the sample and the camera equalize the pressure in which is maintained a pressure acting in the wellbore. Receiving tank equipped with a shut-off valve that allows you to maintain the pressure of the sample fluid after extraction probovatel formation from the borehole for transportation to the laboratory complex. DL the compensation of the reduction of pressure during cooling of the inlet tank and its contents mechanism of the reciprocating pump of this device is made with the possibility of increasing the sample pressure to a level exceeding the saturation pressure by a sufficient margin, so if there is any pressure drop due to cooling of the pressure of the sample fluid does not drop below its saturation pressure.
On pig picture shown with the block diagram, which shows performed in accordance with the invention, the formation tester located in the bore at the level of the test layer contributes through its sampling probe with a reservoir rock for testing and obtaining one or more samples contained in the rock fluid. On Fig in vertical section shows the area of the borehole 10, passing in the area of rocks 11. Into the well 10 on the cable 12 is lowered, the device 13 for sampling and measurement (aprooval-meter). This device consists of a hydraulic power system 14, section 15 of the sample fluid and section 16 of the sampling mechanism. Section 16 of the sampling mechanism includes a selectively retractable clamping Shoe 17, leaning on the wall of the drilled hole, selectively sliding the sampling probe 18 to the inlet of the device of the fluid, and the pump 19 bilateral actions. If necessary, the pump 19 may be located above the sampling probe 18.
When working device 13 for sampling and measurements have in the borehole 10, raising or lowering it to the cable 1 by means of the winch, on the drum which is wound the cable 12. When the device 13 will enter the zone of the investigated layer, information about the position of the device on the depth obtained from the pointer 20 depth, is entered in the processor 21 of the signal processing and recording unit 22. Electrical wires of the cable 12 in the device 13 are transmitted to the electrical control signals from the control circuit 23, including not shown on the drawing processor.
These electrical control signals is activated hydraulic pump power hydraulic system 14 that provides hydraulic power for operation of the device, in particular, to move the clamping Shoe 17 and sampling probe 18 across the axis of the device 13 to the stop in the breed 11, and the pump 19 bilateral actions. Then the element for intake of fluids, i.e. the sampling probe 18, you can enter in contact with the fluid breed by passing from the control circuit 23 electrical control signals to selectively operate located in unit 13 solenoid valves with the aim of sampling fluids contained in the rock.
On Fig depicts the pump is double acting, used for pumping formation fluid into the wellbore to obtain a sample that does not contain leachate, as well as for injection does not contain leachate sample fluid into the receiving the tank. On Fig shows part is made in accordance with the invention, a multifunction tester layers representing schematically a piston pump and two located in the instrument receiving reservoir for fluid samples. Fig and 13 taken from patent US 5303775, where they are described.
As can be seen in partial schematic form in cross section, shown in Fig, the device 13 for formation tests (the test or probovatel), shown in Fig, is a piston pump unit of a double-action, marked on Fig common position 24. In the case of the device 13 also includes at least one, and preferably two receiving tank 26 and 28 for samples, which optionally can have the same performance. In the piston pump unit 24 has two opposite chambers 62 and 64 through supply channels 34 and 36 are communicated with the respective receiving tanks. Control the release of fluid from the respective chambers in the supply channel of the selected receiving tank 26 or 28 is an electric trepalium valves 27 and 29 or any other suitable valve mechanism to selectively fill the receiving tank. As shown in the drawing, the respective pump chamber can communicate with the breed lies beneath the earth for what ernestu the studied reservoir through the feed channels 38 and 40 cameras educated shown in Fig sampling probe 18 and having a corresponding valve control. The feed channels 38 and 40 may be provided with check valves 39 and 41, if necessary, discharging the pressure in the chambers 62 and 64 when excessive pressure increase. Potentiometer 47 to measure the translational motion tracks the position of the pistons 58 and 60 and the speed of their travel, and then when the known size of the piston cylinder can determine the volume pumped out over time.
On Fig the data analysis rate of fluid flow from the reservoir to three cycles of a pump intended for pumping formation fluid. On Fig presents the graphs of the variation of the pressure in the suction pump, the pressure under the packer, flow rate of linear movement of the piston of the pump and pumped out volume for the three cycles of the pump for sampling in the first example of a process for pumping formation fluid passed without complications.
On Fig shows the graph of the change of pressure in the pump depending on the speed of fluid flow from the reservoir to the three cycles of the pump, characterized in pig and 15. It should be noted that the correlation coefficient (R2) Fig and 14 exceeds 0.99, that is a good indicator of the speed negotiation pumping speed of fluid flow from the reservoir. On Fig PR is dstable second example of process dynamics pumping charts with pressure changes in the suction pump, pressure under the packer, flow rate of linear movement of the piston of the pump and pumped out volume for the three cycles of the pump for sampling the second example of the process of pumping formation fluid, obviously complicated.
On Fig shows the graph of the pressure changes depending on the speed of fluid flow from the reservoir for all cycles of the pump, the appropriate presents for Fig example, for which the correlation coefficient (R2is 0,052, indicating the presence of complications. On Fig shows the graph of the pressure changes depending on the speed of fluid flow from the reservoir to the first two shows on Fig cycles of the pump, showing the correlation coefficient (R2), equal 0,9323, indicating good quality of the sample up to this point.
The present invention provides performance ASPF at the end of each stroke of the piston on the suction side of the pump in the recovery process pressure to determine the mobility, compressibility and coefficient of correlation. The invention allows the construction schedule of changes in mobility over time, which can be delivered to the customer of works on formation test as a measure of confidence that the sample collection is complete. According to OSPF graph of pressure dependence of the speed of flow of the fluid from the reservoir, such pok is related to Fig. The closer the plot to a straight line, the higher the correlation coefficient. Obtaining the correlation coefficient over 0.8 is an indication that the pumping speed is in good agreement with the ability of the rock to give the layer of fluid.
Graph of pressure against time allows you to set pressure P* as a result of solving the equation P(t)=P*-[reciprocal mobility]×[the rate of flow from the reservoir]. This graph has a negative slope angle and intersects the vertical axis, on which deferred the pressure P, at the point corresponding to the value of R*. Reverse behaves depending on the speed of the inflow of reservoir fluid mobility. The degree of approximation of the graph to a straight characterizes the correlation coefficient. If the correlation coefficient falls below 0,8, it shows the complication of the process of pumping. The invention allows the operator to signal the up arrow to increase the speed of pumping, if the breed is able to give the fluid in a single phase state at a higher speed, pumping, or signal the down arrow to decrease the speed of pumping, if the pumping rate exceeds the ability of the rock to give the fluid in a single phase condition.
The working volumes of the chambers 62 and 64 are known in advance, and the position and speed of movement of the pistons 58 and 60 are measured by the potentiometer 47, d is the query result which OSPF is held at the end of each stroke of the pump is double acting. Because the absorption rate and the working volume of the known position of the piston and the speed of its change, as well as the size of the chambers 62 and 64, the volume that creates depression, also known or can be calculated.
It is true that Psaturation-P*=-(1/mobility) (speed of flow from the reservoir). The difference of Psaturation-R* represents the amount of pressure that separates the sample from the transition in two-phase state. Using OSPF, you can determine the mobility of the formation fluid based on the calculated rate of flow from the reservoir, and the corresponding pumping rate of qddin equation (16) is calculated in such a way as to be consistent with the rate of flow from the reservoir, as discussed below. The controller downhole tool automatically adjusts the pumping speed, sending feedback signals to control the hydraulic valves of the pump, or sends the operator a signal to adjust the pumping speed in such a way as to achieve the optimal speed of pumping consistent with the mobility of the formation fluid.
When in the process of pumping the piston 58, 60 of the pump is double acting completes its working stroke, the suction side of the pump is OSPF. Before the piston 58, 60 of the pump will begin to move, using OSPF based data recovery pressure the formation fluid at the end of the corresponding stroke of the pump stroke of its piston) for the pumped fluid are determined compressibility, mobility and the correlation coefficient. Thus provided by the present invention perform ASPP during pumping allows for the selection of single-phase samples to obtain data on the potentiometer and the size of the pump the exact amount in which you are creating the depression, and the rate of absorption. Obtained by OSPF data in relation to mobility, compressibility and graphs of pressure differentials provide validation of assay data and hydrodynamic testing. Therefore, the holding OSPF in the process of pumping ensures that for accurate hydrodynamic testing and obtaining single-phase samples, characterizing wireline fluid used properly-speed suction.
In accordance with the existing option of the present invention, shown in Fig-19, a device and method for controlling the pumping of fluids from oil - and gas-bearing rocks and ensuring quality control of pumping by applying the above method ASPF after each stroke of the pump. OSPF is held on the suction side of the pump control process recovery pressure of formation fluids provided by the invention using OSPF to calculate mobility, compressibility, coefficient of correlation and p* time. Proposed in the invention method enables to analyze rez is ltati measurements, obtained by the formation tester on the cable against the formation pressure and mobility of formation fluids, by applying the above method ASPF after each step shown in Fig pump double acting. With the help of test layers usually are pumping formation fluid into the wellbore or pumping formation fluid, prior to sampling to ensure the absence of mud filtrate. Pumping fluid to obtain a clear filtrate samples can last for hours. In addition, the important point is the need to maintain the most effective pumping speed, avoiding complications such as blockage of the downhole device, the leakage of the packer, sand or rock. In accordance with the invention OSPF is conducted with respect to process parameters pumping using a known displacement chambers 62 or 64 of the pump is double-acting.
As shown in Fig, OSPF is performed after each stroke of the pump or multiple bars together. OSPF accompanied by one or more cycles of the pistons 58 and 60 in the chambers 62 and 64 of the pump is double acting to determine the mobility of the fluid in the rock, the compressibility of the fluid and the correlation coefficient. Mobility, defined according to OSPF, shows the ability of the rock to give uglevodorov the s. For efficient production, it is extremely important to ensure the ability of the rock to give the contained fluid and an acceptable rate of pumping. Knowledge of the ability of the rock to give the contained hydrocarbons accordingly allows this ability to adjust the pumping speed, or reducing the rate of low mobility or increasing it at high mobility. Maintain pumping accordingly the ability of the rock to give the fluid helps to achieve efficient pumping. Using the value of mobility defined using OSPF in the process of pumping, calculated the maximum pumping speed at which the pressure in the flow of formation fluid remains above the saturation pressure, or the beginning of the evaporation. The adoption rate of pumping, determined by calculation, using OSPF in the process of pumping, increases the chances to take nerazgadannoi sample in-phase condition and reliably characterizing the header.
The definition of the correlation coefficient according to OSPF allows you to get the quality indicator process pumping and the presence of possible complications. When pumping fluid can be faced with numerous challenges. The identifying characteristic such problems at an early stage provides an important opportunity to avoid costly, if not catastrophic the ski, failure of the downhole tool and allows the operator of the device to change the pumping speed, pause pumping out or even stop it. In a typical embodiment of the invention the processor, which is equipped with a downhole tool, informs the operator in relation to the desired speed and whether the pumping speed to increase or decrease, displaying on a screen located on the surface of the operator of the arrow "up" or "down" or stop pumping, either automatically adjusts the pumping speed or stops the pumping to eliminate in the study revealed when pumping complications.
If the pumping is without complications, the correlation coefficient, defined by OSPF for a series of continuously following each other cycles of the pump is relatively high, i.e. more than 0,8-0,9, but in case of complications, the correlation coefficient according to OSPF fall again. Compressibility determined by OSPF, is used as an indicator change type of fluid during pumping. By constantly monitoring the compressibility of the reservoir fluid, you can quickly notice a change in the type of fluid pumped from the reservoir. Thus, if the compressibility of the mud filtrate and the compressibility of the reservoir fluid, there is a significant difference, it is relatively easy to control the degree of purification of the rocks of the reservoir leaked from her mud filtrate as as the compressibility will vary from values indicating the mud filtrate, to the value indicating the layer of fluid. To determine the purity of a sample of formation fluid control measurements of the spectral optical density in the near-IR region, combined with the compressibility according to OSPF.
As shown in Fig-19, in this embodiment, the invention features an apparatus and method for quality control of pumping through the analysis of the rate of fluid flow from the reservoir, or abbreviated OSPF, over time for each stroke of the pump. Pumping can last hours, and the conduct of the process in the most efficient manner, avoiding complications such as blockage of the downhole device, the leakage of the packer or the caving is a very important question. The present invention provides for OSPF in relation to the characteristics of the process of pumping at a known working volume of the pump. OSPF is carried out for each stroke of the pump or to a few bars together. Holding ASPF after one or more cycles gives the mobility of the fluid in the rock, the compressibility of the fluid and the correlation coefficient. In accordance with the invention, the mobility was determined using OSPF, is used as an indicator of the ability poro the s layer to give the contained fluid. In this embodiment of the present invention determining the ability of the rock to give the fluid is used to select the appropriate speed pumping, allowing a smaller value (for example, if the data ASPF indicate low mobility) to reduce the pumping speed, receiving a fluid with less intensity, or increase the pumping speed, if the breed has a higher return (in case of high mobility)that provides increased efficiency due to the additional correction speed pumping to bring it into conformity mobility contained in the rock fluid. Measuring in the process of pumping mobility contained in the rock fluid through OSPF, in accordance with the invention, it is possible to calculate and implement the corresponding maximum mobility pumping speed at which the pressure of the sample flowing through the pump and the downhole tool, will exceed the saturation pressure, and the pumping process will take no more time than would be required to obtain samples at too slow pumping. The chances of getting nerazgadannoi a representative sample increase, if you apply the maximum pumping rate, calculated according to the invention using OSPF in accordance with the mobility of the fluid at the end of each pumping cycle of the pump is double-acting.
Requirementsdoresti pumping fluid from the breed in accordance with the mobility of the fluid in this breed optimizes the process of pumping by speed negotiation pumping intensity of the return fluid breed. Negotiation speed pumping with the ability of the rock to give the fluid ensures that injected into the receiving reservoir sample reservoir fluid will remain in single-phase state throughout the process of pumping, which is achieved by eliminating the possibility of conducting pumping intensity that exceeds the ability of the breed to give fluid, not allowing the pressure in the sample fluid to drop below the saturation point. The present invention also allows the quality control in real time to detect signs of any complications as they arise and to issue the appropriate signals or automatically change the settings of pumping to minimize adverse effects. The degree of purification of the breed from pollution control to change the compressibility of the fluid based on the data ASPH. Thus, the present invention allows to optimize the process of pumping by complex OSPF in the process of pumping. Accordingly, the invention provides a win, which consists in obtaining a representative sample of formation fluid.
Method OSPF in relation to the characteristics of pumping can be easily integrated in the test and probovatel layers as additional features that can be turned on and off. After enabling optimization of the pumping mobility, gripping the edge of your is resistant and the correlation coefficient according to OSPF constantly monitored in real time. In this embodiment, the invention preferably includes the following steps.
The present invention provides for the use of OSPF based on the known volume of the chambers 62 and 64 of the pump is a double-action or pump chamber unilateral action. Method OSPF can be used in relation to one stroke of the pump or of several such cycles, calculating mobility, compressibility and coefficient of correlation for the corresponding single clock cycle or multiple cycles. On the basis of specific data ASPF mobility of the fluid in the rock, the invention provides for the calculation of the optimal speed pumping to maintain pressure flow level above the saturation pressure, and informing the control device engineer about whether to change the parameters of the process of pumping to achieve the optimum pressure and automatically adjust the speed pumping to achieve the optimum pressure at which the pumping speed is consistent with the ability of the rock to give the contained fluid. The invention provides for continuous monitoring during the process of pumping for mobility, compressibility and coefficient of correlation, based on OSPF on the subject of significant changes in the above variables to determine the ability to breed Ottawa the ü fluid or detection of complications when pumping.
Method OSPF allows to determine the rate of fluid flow from the reservoir for subsequent analysis. At the heart of this analysis lies in the following equation:
In the right part of equation (16) the second term in brackets - (CsistVsist(dp(t)/dt)+qdd) - fully represents the rate of fluid flow from the reservoir, calculated by correcting the moving speed of the piston (qddon the basis of the parameters and conditions downhole tool. Withsistis the compressibility of the fluid in the hydraulic line of the device, and Vsist- volume hydraulic lines. G0- this is a geometric factor, and riis the radius of the sampling probe.
On Fig-19 the following symbols are used: APQK - curve of pressure according to the gauge on the pump, pounds per square inch; APQL - curve of pressure according to the gauge of the packer, the pound per square inch; LMP - curve linear movement of the piston changes the volume of the pump chamber or inlet chamber for sampling. The positioner piston pump is shown in Fig potentiometer 47 to measure the translational motion. Potentiometer for measuring the parameters of the translational motion is used to track how the piston position and speed of its movement. On this curve, using the cross-sectional area of the piston us the sa in centimeters, calculate the volume (DDV), which creates a depression, and pumped volume (PTV). Curve evacuated volume (PTV-BB) is constructed from data measured in cm3. OSPF you can use when pumping with pump a small amount, equal to 56 cm3when the volume of the pump chamber are shown on the graph evacuated volume (PTV).
On Fig as an example, the data ASPF when conducting evacuation pump a small volume. These figures include R* 1410, mobility 1412, compressibility 1414 and the correlation coefficient 1416. Process data pumping were considered and analyzed for each cycle. Then the data for each of the three cycles 1402, 1404, 1406 were mixed 1408. On Fig shows graphs used data process pumping in time. As shown in this figure, were used in the analysis three working stroke of the pump a small volume. The results of the analysis are summarized in Fig. It should be noted that to calculate the rate of absorption instead of volume (DDV), which creates a depression, was used curve evacuated volume (PTV).
On Fig shows the pressure 1506 in the pump, the pressure 1504 under the packer (hydraulic cuff), the position 1502 of the piston and pump out the volume 1508. On Fig shows the change in the parameters of pumping in time three working stroke of the pump-type "BB" with a double-seat valve (abbr. "blue bearings") for sampling of 56 cm 3. On Fig given the graph of the results ASPF characterizing three working stroke, shown in Fig together. Presented at Fig dynamics of the process of pumping in time is characterized by the correlation coefficient 0,9921 obtained for three shows on Fig ticks.
As shown in Fig, on each stroke of the pump mobility and compressibility of the fluid change, but their values are very close. Mobility increases only slightly. The results ASPF obtained for three cycles of the pump, taken together, i.e. in combination with each other, in fact, represent the values of the compressibility and mobility, averaged over three work cycles. Presented at Fig graph 1604 results ASPF for three cycles in the aggregate, shows a relatively good correlation of the results obtained with direct 1602 (correlation coefficient 0,9921). The above example shows that OSPF succeeds in relation to the process parameters pumping when using the RCI device (Reservation Characterization Instrument) with pump type "BB" volume 56 cm3and using curves evacuated volume (PTV). OSPF is performed for each beat or to save time calculations can be carried out in relation to several measures taken together.
On Fig shows the results ASPF for several measures in the ri, the complication of the process of pumping. As shown in Fig and 18, the first few cycles have passed without problems, but then the behavior of the pressure gives the signs of complications (e.g., low permeability reservoir, high viscosity or clogging downhole tool). On Fig shows the graph of the pressure changes depending on the speed of fluid flow from the reservoir based on the results ASPF for the whole population cycles where the correlation is barely noticeable, if noticeable at all (the correlation coefficient is very low, 0.03). However, for the first few cycles result OSPF, as shown in Fig, quite good: the correlation coefficient is 0.93; mobility - 1040 MJ/SP, and the compressibility of 4.1×10-4(1/lb on the square inch). This example illustrates the use of OSPF in the process of pumping in the quality of execution pumping. The present invention allows OSPF for several cycles of evacuation and to calculate or to note the change on the graph data ASPF or correlation coefficient to detect possible signs of complications during pumping. In this embodiment, the invention allows to determine any such significant change, then the operator sent the corresponding request or message, or automatically adjusts the pumping speed, the system checks for possible complications, either because the crust is Evesham state, requiring the cessation of pumping, the pumping stops.
The saturation pressure of formation fluid or a mixture of formation fluid from the filtrate can be assessed by well test fluid expansion or on the basis of known data extracted from databases and representing the correlated values. After by ASPF received the mobility of the fluid in the rock formation, using OSPF calculates the maximum pumping rate that can maintain pressure when pumping at a level exceeding the saturation pressure. In addition, any significant change in the value of compressibility according to OSPF, for example, half of the order or on the order involves changing the type of arriving in the device of the fluid, which will serve as an indicator of clearing rocks from contamination (in the near-wellbore area of the formation).
In accordance with the present invention from the total number of cycles completed by the pump when creating depression, few are chosen, and on the basis of the calculated speed of the suction receive data ASPH. For the parameters of the process of pumping the analyzed interval is selected based on the number of cycles of the pump, and not the rate of absorption. The invention provides for pumping at a variable number of cycles of the pump, and in the beginning of the process selects a few small bars, for example two or three steps, and post the foam by increasing the number of cycles of the pump to the specified maximum for example, ten cycles, which in this example corresponds to about 500 cm3drained fluid.
On Fig schematically presents the sampler. The present invention allows the use of OSPF when pumping from the rock sample fluid. Execution OSPF allows us to calculate the characteristic changes of compressibility, permeability and mobility over time. Tracking changes in permeability over time allows us to estimate or determine the degree of contamination of the sample filtrate. Since the compressibility of the reservoir fluid is greater compressibility of the filtrate, compressibility curve steadily goes down and as the pumping fluid from the reservoir rock and the disappearance of the filtrate impurities in the fluid asymptotically rectified at some fixed value.
As shown in Fig, wireline fluid pumped from the rock 2010 pump 2018. Coming from rock 2010 the fluid is directed either to the outlet 2012 in the wellbore for pumping fluid to clean from dirt or in the receiving tank 2020 for samples, for storing samples in single-phase state, and is taken as a sample 2021, once it is established that it does not contain impurities. The present invention provides the ability to monitor the dynamics of changes of compressibility, permeability and mobility in real time, which allows the control of selected samples with the to this sample of fluid remained in the same condition in which fluid was in the breed.
On the suction side 2014 pump 2018 pressure falls below the formation pressure, causing the flow of formation fluids from the rock into the pump 2018. The magnitude of decrease in pressure below the formation pressure at the suction side of the pump is set in accordance with the present invention. In particular, this pressure difference is set so that the pressure in the sample fluid does not drop below the saturation pressure. When determining the magnitude of the pressure drop on the suction side of the pump stem also from the condition that the pressure in the sample fluid must not fall below the pressure of the beginning of asphaltene precipitation, allowing the sample fluid remains in the liquid state, in which the fluid was in the rock formation. Accordingly, there is a first differential pressure, which is set so that the pressure when pumping has not fallen below the saturation pressure and has not begun the formation of gas bubbles. There is also a second differential pressure, which is set so that the pressure when pumping has not fallen below the pressure at which the reservoir fluid begins precipitation of solid substances, such as asphaltenes. Thus, using the above-mentioned first and second differential pressure ensures the delivery of the sample reservoir is of luida without phase change, associated with the formation of additional gases or solids. The first and second pressure drops are determined by the saturation pressure and the pressure at the beginning of the deposition of asphaltenes obtained by simulation or analysis of previously obtained information about the reservoir. Control of the cleaning process samples of fluid from the filtrate ensures that the sample of formation fluid does not contain leachate or contains it in a minimal amount, so the composition of the sampled formation fluid authentically replicates the composition of the formation fluid, when it is contained in the rock formation.
In yet another embodiment, the present invention offer in the way it is implemented in the form of a set of executable computer commands that are recorded on a machine-readable data carrier, comprising a persistent storage device (ROM), random access memory (RAM), CD-ROM (CD-ROM), flash memory or computer-readable media of any type whatsoever, known or unknown at the present time, and in the performance of the computer implements proposed in the invention method.
Although in the above description were considered specific examples of the invention, a specialist should be obvious various changes may be made in the variants of the invention. L is all such changes, subject set forth in the claims of the patent claim considered as covered by the above description. In this description have been quite widely reported examples of the more important features of the invention, to facilitate understanding of the subsequent detailed description and evaluation of the contribution made by the invention in the prior art. Of course, there are also additional features of the invention which will be described later, and is available in the accompanying claims.
1. The method of estimating the rate of fluid flow from the rock (218), comprising pumping fluid from the rock (218) using placed in the borehole pump (426) and the dimension in the process of pumping pressure fluid and the pumped volume (47) using placed in the borehole sensors (424), characterized in that the track in the process of pumping evacuated volume, estimate the speed of fluid flow on the basis of the results of measurements of pressure and volume, and set the pumping speed of the fluid providing fluid almost in-phase condition.
2. The method according to claim 1, characterized in that the tracking pumped out volume includes tracking the position of the pump piston (58, 60).
3. The method according to claim 1, characterized in that the measuring pressure of the fluid is carried out by measuring the pressure in hydrauli eskay line fluid.
4. The method according to claim 1, characterized in that based on the speed of fluid flow estimate at least one of the following options: rock permeability for fluid, fluid mobility and compressibility of the fluid.
5. The method according to claim 4, characterized in that the output of the specified parameter for the specified limit detect complications with the pumping.
6. The method according to claim 4, characterized in that the measurement is specified over time the quality of the fluid.
7. The method according to claim 4, characterized in that the evaluation results of the specified parameter determine the correlation coefficient and the correlation coefficient reveals a complication when pumping.
8. The method according to claim 4, characterized in that observe the change in the specified time to determine the purity of the breed from contamination.
9. The method according to claim 1, characterized in that observe the change in velocity of fluid flow over time to determine whether the sample of formation fluid in a single phase condition.
10. The method according to claim 1, characterized in that the estimate of the correlation coefficient between the rate of fluid flow and pressure and on the basis of this correlation coefficient regulate the pumping speed.
11. The method according to claim 1, characterized in that the estimate of the correlation coefficient between the rate of fluid flow and pressure and support shall indicate the pressure of fluid above pre-measured reservoir pressure.
12. The method according to claim 11, wherein based on the specified correlation and reduce the pumping speed to maximum to get fluid in a single phase condition.
13. Device for extracting fluid from the rock in which the well containing placed in the borehole pump with the monitored volume to extract fluid and placed in the borehole sensor (424) pressure for measuring the pressure of the fluid, characterized in that it comprises a processor (418), programmed to eject fluid based on the volume and pressure and determine the speed of the pumping fluid providing fluid in a single phase condition.
14. The device according to item 13, wherein the processor (418) allows you to change the pumping speed for the optimization of the extraction fluid.
15. The device according to item 13, characterized in that it comprises a tank (26) for the extracted fluid.
16. The device according to item 13, wherein pumped by the pump from the rock fluid is supplied by this pump through a hydraulic line (22) in the chamber fluid samples.
17. The device according to item 13, wherein the processor (418) is programmed to estimate a parameter selected from the group consisting of permeability, mobility and compressibility.
18. The device according to 17, characterized in that the processor (418) is able to identify the complication of pumping at the exit of the specified pair is of the ETP during a specified limit.
19. The device according to 17, characterized in that the pump is able to extract the fluid with the speed set on the basis of the specified parameter by ensuring that the fluid is almost in-phase condition.
20. The device according to 17, characterized in that the processor (418) is able to identify the complication of pumping on the basis of the specified parameter.
21. The device according to 17, characterized in that the processor (418) is able to assess the quality of the fluid based on the measurement of the specified parameter over time.
22. The device according to 17, characterized in that the processor (418) is programmed to estimate the correlation coefficient for the evaluation of the specified parameter and identify complications of pumping on the basis of this correlation coefficient.
23. The device according to 17, characterized in that the processor (418) is able to control the change of the specified time to determine the purity of the breed from contamination.
24. The device according to 17, characterized in that the processor (418) is able to control the change of the specified time to determine whether the sample of formation fluid in a single phase condition.
10.03.2003 according to claims 1, 2, 4-6, 8, 10-24;
23.04.2003 on PP, 7, 9.
FIELD: oil and gas industry.
SUBSTANCE: invention refers to subsurface sampling and specifically to continuous measurement of concerned parameters, as well as hydrocarbon sample analysis performed on sampling point after installed in sampling chamber of the downhole device. The device contains downhole sampling chamber for formation fluid sample and control module connected by fluid channel to a part of formation fluid sample in downhole sampling chamber and designed to control concerned parameter of formation fluid sample. Besides method for controlling concerned parameter of formation fluid sample is offered.
EFFECT: provided continuous control of sample integrity including sample surfacing to its delivery to analysis laboratory.
23 cl, 4 dwg
FIELD: oil and gas industry.
SUBSTANCE: invention is applicable to the oil industry and particularly to equipment used for formation testing in oil production. The sampler consists of a cylindrical housing containing a sampling module that includes a flow-type sample receptacle, valve gear, and magnetic separator strainer; hydraulic drive module including a cylindrical chamber, ballast chamber, piston, push rod, and solenoid valve; electronic module including power supply unit and set of physical metering sensors connected with an electric recording circuit. The solenoid valve is located inside the piston of the hydraulic drive module; the sampling module is additionally fitted with a sealed chamber with one end connected to the rod and the other end connected to the valve gear; and the electronic module is additionally fitted with a piston proximity sensor.
EFFECT: better quality of information measured, as well as simplified and more reliable operation of mechanism components.
FIELD: oil and gas industry.
SUBSTANCE: invention is related to oil and gas industry, in particular, to procedure of fluid and gas sampling in wells. Device consists of cylindrical casing, where the following components are installed: sample receiving chamber of suction type with separating piston, ballast chamber, module of control and information exchange interface. The following components are introduced into cylindrical casing between sample receiving and ballast chambers, leakproof relative to environment, serially connected downstream sample receiving chamber: uncontrolled adjustable reduction gear of fluid pressure and hydraulic relay controlled by electric current that is supplied from module of control and information exchange interface, which uses elastic mechanic oscillations excited on device body and noise-immune coding of information for control of device operation, and also for communication to personal computer.
EFFECT: increase of device operation reliability, monitoring of sample receiving chamber opening and time of its filling with fluid, expansion of equipment operation thermobaric range, provision of sample transport safety.
5 cl, 1 dwg
FIELD: oil and gas industry.
SUBSTANCE: invention relates to devices for sampling of horizon fluids from gas and oil wells at specified depth. The technical result is achieved in the mechanism of valve control by means of the following: in a case with a bushing and a plunger with holes for a calibrated pin positioned therein the mechanism is additionally equipped with a device in form of a cartridge located in the case of the mechanism above the bushing and interacting with the upper part of the plunger equipped with sealing rings insulating a cavity of the cartridge placed above the upper part of the plunger.
EFFECT: upgraded reliability and quality of sampling at any horizon conditions including aggressiveness of horizon and also possibility of operation of mechanism valve control with majority of employed types of samplers.
FIELD: mining; physics.
SUBSTANCE: device includes seat and ferromagnetic valve, the seat being equipped with a permanent magnet system, while the valve has ferromagnetic inserts with Curie magnetic transition point equal to oil temperature at the sampling site.
EFFECT: improved device efficiency due to actuating valve device at given oil sampling site and creating additional press force.
FIELD: petroleum industry.
SUBSTANCE: invention relates to the mining industry and can be used for taking subsurface samples of oil in production and exploration wells, mainly operating by the natural flow production method. The subsurface sampler contains the receiving chamber, the upper and the lower valves, the piston, sealing assemblies, valve rods for retaining samples in the sampler, the locking mechanism, the upper head and the lower tail piece with a hole for passing the fluid; the sampler is also provided with a stirrer located in the receiving chamber between the upper and the lower valves. The piston is of cylindrical form with axial boring, in which a spring-loaded valve is accommodated. The retaining and restricting nuts are provided in the bottom of the piston. The subsurface sampler is made so that it can be connected with the valve control mechanism in the upper and in the lower parts of the sampler.
EFFECT: increased strength of the sampler and operational reliability.
2 cl, 3 dwg
FIELD: petroleum industry.
SUBSTANCE: invention relates to investigations of subsurface samples of fluids and particularly, to taking aliquot subsurface microsamples of formation fluids for conducting in-situ express analysis. The well device contains the sampling tank and several microsampling chambers. Microsampling chambers may have at least one window for input of energy of visible emission, emissions in the near and middle fields of the infrared range and energy of other kinds of electromagnetic emission into the tank for samples collected in the microsampling chamber, in the well or downhole. Such window can be made of sapphire or another material transparent for electromagnetic emission. Besides the whole microsampling chamber can be made of sapphire or other material transparent for electromagnetic emission with a possibility of visual control or analysis of samples in the microsampling chamber. The microsampling chamber makes it possible to immediately analyse a sample obtained in situ, on the surface to determine the quality of the sample contained in the main sampling tank or to make thorough analysis of the same.
EFFECT: increased sampling capacity and express analysis of samples, more accurate determination of the parameters of the sample.
30 cl, 8 dwg
SUBSTANCE: invention relates to determination of various well characteristics in the underground formation, through which the borehole passes. For this purpose a pressure drop is created due to the difference between the internal pressure of fluid that passes through the drilling tools and pressure in the circular space in the borehole. The device contains an extension arm that can be connected with the drilling tools and has an opening that enters into the chamber in the extension arm. A piston is located in the chamber with a rod passing through the opening. The piston can move from the closed position when the rod blocks the opening to the open position when the rod is retracted into the chamber to form a cavity for intake of well fluid. A sensor is located inside the rod, which is intended for data collection from the well fluid contained in the cavity.
EFFECT: increase of accuracy of determination of well characteristics.
34 dwg, 9 dwg
FIELD: method and sensor for gas monitoring in well environment.
SUBSTANCE: method involves providing infrared light-emitting diode in well; transmitting corresponding infrared signals to the first optical path extending from the diode through well gas sample and the second optical path extending from the diode through gas sample; detecting transmitted infrared signals and determining concentration of component in well gas sample from detected signals. The first optical path is free of liquid.
EFFECT: increased accuracy of gas monitoring.
36 cl, 4 ex, 19 dwg
FIELD: equipment for reservoir gas presence in drilling mud flow passing via well during well drilling.
SUBSTANCE: device comprises at least on sensing chamber to be connected to drilling string for well drilling. Each sensing chamber contains taken gas volume and comprises membrane wall for reservoir gas penetration from drilling mud flow in sensing chamber. Sensor provides determination of said gas volume characteristics change caused by reservoir gas penetration from drilling mud flow in sensing chamber through membrane wall.
EFFECT: increased reliability and accuracy of gas detection.
16 cl, 4 dwg
FIELD: oil and gas extractive industry.
SUBSTANCE: method includes picking a sample of bed fluid under pressure by means of pump. Sample of fluid is then compressed by moveable piston, actuated by hydrostatic pressure in well through valve. Compressed sample of bed fluid is contained under high pressure inside the chamber with fixed volume for delivery to well surface. Moveable piston is in form of inner and outer bushings, moveable relatively to each other. At the same time several tanks for picking samples from several areas may be lowered into well with minimal time delays. Tanks may be emptied on well surface by evacuation pressure, to constantly provide for keeping of pressure of fluid sample above previously selected pressure.
EFFECT: higher reliability.
6 cl, 14 dwg
FIELD: oil industry.
SUBSTANCE: device has hollow body which is a fragment of force pipeline at vertically placed portion of mouth armature. Tool for controlling flow of multi-component gas-liquid substance is made in form of valve, connected to rotary support. Sample chamber is a ring-shaped hollow in hollow body, placed at same level with valve and connected at inlet to flow of multi-component gas-liquid substance through extracting channels, made on hollow body. Extracting channels are made in form of side slits, positioned symmetrically relatively to valve rotation axis. Ring-shaped hollow on hollow body is connected at outlet to locking tool, mounted at extension of valve shaft and made in form of sample-taking valve. Valve shaft and sample-taking valve are interconnected through hollow intermediate shaft. Sample-taking valve is placed in the body of locking tool with possible reciprocal movement. Valve shaft and hollow intermediate shaft are interconnected with possible mutual rotation for a quarter of one turn.
EFFECT: simplified construction and maintenance, higher quality.
FIELD: oil and gas industry.
SUBSTANCE: device has body in form of calibrated cylinder. From both sides lids are connected to body. Inside the body separating piston and ball for mixing sample are placed. Also provided is hydraulic resistance for slow inlet of sample. Slide valve is used for safe inletting, pressurization and depressurization of taken fluid, is connected to lid and consists of rod with channels and bushing with clamp. Clamp is held between nuts interconnected by threads, one of which is connected to rod by thread. Needle valve consists of locking pin and axle-bearing and is used to drain pressure from closed space above slide valve prior to disconnection of sample-taking container from bed-testing equipment.
EFFECT: simplified construction, higher reliability.
FIELD: oil industry.
SUBSTANCE: device has hollow body mounted in force pipeline, inside of which body tool for controlling flow of multi-component gas-liquid substance is placed, probing chamber with extracting channels, locking tool with handle and guiding pipe, driving valve for picking sample, mounted with possible interaction with spring-loaded rod, placed inside the shaft of flow control tool. Hollow body is a fragment of force pipeline at vertical portion of mouth armature, control tool is made in form of valve of lesser diameter, then inner diameter of hollow body, and probing chamber is a ring-shaped hollow in hollow body, positioned at same level with valve and connected at input to flow of multi-component gas-liquid substance through extraction channels, made symmetrically to rotation axis of valve, and at output - to locking tool, while rod is provided with shelves for multi-start thread of appropriate cross-section, made at shaft on length of no less than quarter of axial step of this thread.
EFFECT: simplified construction, higher efficiency.
FIELD: oil industry.
SUBSTANCE: device has hollow cylindrical body, branch pipes for extraction and output of sample and locking element. Body is made thick-walled. End portions of body are made in form of truncated cone and interconnected, on the side of lesser bases by means of channel. Branch pipe for extraction of sample is made elongated, with length equal to body diameter, and is let through in transverse direction of body through the center of said channel. Within limits of branch pipe cross-section its hollow is separated by slanted solid wall on two portions, each of which is connected thereto. One portion of branch pipe hollow is meant for taking sample, other one - for feeding reagent into well product. To receive trustworthy information about sample, by setting flow to homogenous state, inner surface of cone, on the side of larger base, is provided with rigidly fixed blades for turbulization of flow flowing into body, while diameter of channel connecting cones is selected equal to diameters of their lesser bases.
EFFECT: simplified construction, broader functional capabilities, higher quality of sample.
2 cl, 3 dwg
FIELD: oil industry.
SUBSTANCE: hollow body of device is actually a fragment of force pipeline at mostly vertical portion of mouth armature. Organ for controlling flow of multi-component gas-liquid substance is made in form of valve mounted on shaft having lesser size, than inner diameter of hollow body. Sample chamber is in form of ring-shaped hollow on hollow body, positioned at same level with valve. Ring-shaped hollow is connected at input to flow of multi-component gas-liquid substance through intake channels, positioned symmetrically to valve rotation axis, and at output - with locking organ. Driving screw mounted on body of locking organ is connected to sample-taking valve with possible mutual rotation and combined axial displacement. Sample-taking valve and shaft with valve are mated with possible synchronous rotation around common axis and relative axial displacement. Working organs of device are positioned immediately near main flow of substance taken as sample to provide for lesser dimensions of device and prevented freezing in winter season.
EFFECT: simplified construction, simplified maintenance.
FIELD: oil production industry, particularly methods or devices for cementing, for plugging holes, crevices, or the like.
SUBSTANCE: device comprises inflatable packers to be lowered into well along with flow string. One flow string end is closed to provide simultaneous well bore packing, another end is connected to production equipment. Flow string is provided with centralizers located near inflatable packers. Formed in flow string are additional holes located opposite to packers. Well pump is installed inside flow string. High-pressure water conduit having low diameter is connected to above holes. Flow string has perforated orifices created between inflatable packers.
EFFECT: extended operational capabilities.
FIELD: oil-field equipment, particularly for obtaining fluid samples or testing fluids in boreholes or wells and may be used for integrated obtaining sample of multicomponent liquid-gas systems transported through pipelines.
SUBSTANCE: sampler comprises hollow body installed in high-pressure pipeline of wellhead fittings and extraction chamber with discharge channels. Rotary tool adapted for multicomponent liquid-gas medium flow regulation is installed inside the body. Sampler also has shutoff member with actuated sample extracting valve, handle and guiding tube. Sampler comprises hollow body made as a part of high-pressure pipeline and tool adapted for multicomponent liquid-gas medium flow regulation arranged in hollow body. The tool consists of flap installed on a shaft and having diameter corresponding to inner hollow body diameter, extraction chamber used to extract and mix multicomponent liquid-gas medium flow formed as annular cavity around hollow body. The cavity is divided into inlet and outlet parts by partition arranged at flap level. Inlet and outlet parts communicate with common multicomponent liquid-gas medium flow correspondingly through inlet and outlet channels on hollow body and through opening formed in the partition at sample extracting valve inlet. Drive screw installed in shutoff member body is connected with sample extracting valve so that drive screw and sample extracting valve may perform mutual rotation and move in axial direction. Sample extracting valve and shaft with flap mate each other so that they may perform synchronous limited rotation about common axis and mutual axial movement.
EFFECT: increased simplicity, provision of high-quality mixing of sample product and increased sample reliability.
FIELD: oil field equipment, particularly for take samples from wellhead, namely for integrated sampling multi-component gas-liquid medium transported through pipelines.
SUBSTANCE: device has hollow body built in pressure pipeline and formed as a part of the pipeline located on vertical part of wellhead fittings. Multi-component gas-liquid medium flow control unit is made as a gate connected to rotary support shaft. Sampling chamber is created as annular cavity arranged on hollow body at gate level. Sampling chamber inlet is communicated with multi-component gas-liquid medium flow through intake manifolds formed on hollow body. Intake manifolds are side slots arranged symmetrically about gate axis of rotation. Sampling chamber outlet is communicated with shutoff member installed on rotary gate support shaft extension. Shutoff member includes seat, hold-down screw and ball contacting with the seat and embedded in pressure screw end.
EFFECT: simplified structure and increased sampling quality.
FIELD: mining industry, particularly to take subsurface oil samples in running and exploratory wells working in flow mode.
SUBSTANCE: sampling device has tubular body with lock mechanism arranged inside the body and connected to controlling valve assembly from the first side and controllable valve assembly from the second side thereof. Joint relay is screwed on the controlling valve assembly. The controlling assembly is retained in its opened position by joint relay including body with orifices for pin receiving, pusher acting upon the controlling valve assembly and bush with fluid circulation orifices. Valve assemblies include all-rubber valves having 30° cone angles. The relay has barbs to engage with production string connector. When sampling device moves downwards the barbs are brought into folded state.
EFFECT: increased operational reliability and prevention of oil sample degassing due to improved air-tightness of sampling device interior.
2 cl, 1 dwg