System and method of correction of well shaft direction based on stress field

FIELD: oil and gas industry.

SUBSTANCE: method includes stress inducing in formation around well shaft in order to generate in it some special feature related to induced stress. Measurements presenting well shaft geometry are performed using assembly of drilling string bottom rotated in well shaft, which geometry presents induced stresses in formation. Creation of well shaft image based on its geometry measurements. Evaluation of azimuth variation of induced voltage in formation by well depth. Change of parameter of drilling mode for assembly of drilling string bottom using evaluation of azimuth variation of induced voltage in formation by well depth.

EFFECT: using data obtained in real-time mode, checking stress model for certain region, so that the path may be corrected constantly for achievement of optimum ratio with measured characteristics of stress for this region.

21 cl, 12 dwg

 

The technical field to which the invention relates.

The present invention relates in General to the exploration and production of oil and gas and, more particularly, to a method and system for correcting the trajectory of the wellbore.

The level of technology

In the early stages of drilling and oil production wells were drilled, mainly on land, at an average depth and with a relatively small horizontal offset. The development of ideas about the influence of geological forces and properties of rocks in the drilling mode and the practice field development occurred empirical way from region to region. Successful technologies were found by trial and error - sometimes expensive and revealing. Only over time the analysis of situations in specific fields has led to the understanding of drilling and completion of new wells with a sufficient degree of confidence to ensure the security and economic success of the development of the following fields. However, the technique proved successful in one field, was not necessarily that of others, and therefore the process of trial and error often had to be repeated.

Since wells has become increasingly expensive and complex in terms of their geometry (deviation from the vertical and length), access to deep-lying horizons, modes with high values the pace of the atmospheric temperature, pore pressure and stress, it became clear that the economic success of field development can be ensured only if the geological and tectonic aspects and planning on the basis of their operations on the field. Further, restrictions on engineering activities on environmental and social considerations dictate the need to develop special formulations of drilling fluids and methods of drilling. Developing and applying the latest in a very strong degree depends on the understanding of the processes operating in the earth's thicker, and the impact of these processes on the practice of drilling and completion. The discipline dealing with the study of these processes, the relationship between them and their impact on rocks, called geomechanics.

Professionals in this field know that the forces acting in the earth's crust, quantitatively expressed by the stress tensor, the individual components of which are voltage (dimension "force per unit area"), acting perpendicular and parallel to the three planes, which, in turn, orthogonal to each other. Normals to the three orthogonal planes define a Cartesian coordinate system (x1x2x3). Figa, 1b and 1c together illustrate the definition of the stress tensor in Cartesian coordinates (figa), convert the irreducible tensor through the guides of the cosines (fig.1b) and the principal axes of stress (figs).

The stress tensor has nine components, each of which has a direction and magnitude, as shown in figa. Three of them represent the normal stress, in which case the force is applied perpendicular to the plane (S11a component of the stress acting normal to the plane perpendicular to the axis of x1); the remaining six are shear stresses, in which case the force is applied along the plane in a certain direction (for example, S12a force in the direction of x2along the plane perpendicular to the axis of x1). In all cases, Sij=Sjithat reduces the number of independent stress components to six.

At each point there is a certain axis orientation of the stresses to which all shear stress components are zero, and their directions are called the directions of the principal stresses at a given point. Three principal stresses acting in these directions, have a value of S1(maximum), S2(intermediate) and S3(minimum). The coordinate transformation between the tensor principal stresses and any other arbitrarily oriented stress tensor are made by turning. In most places around the globe at depths where comes the drill bit, the stress acting vertically on the horizontal plane (defined as the vertical stress S v), is the main voltage. From this it follows that the other two horizontal voltage must lie in the horizontal plane. Because the horizontal stress will almost always have a different size, they are called the maximum (SHmax) and minimum (SHminhorizontal stresses.

In the earth's thicker there are a number of different sources of stress. Forces driving the tectonic plates have a constant direction over vast areas. Their appearance is due to various reasons, including the formation of seamounts in the area of mid-oceanic ridges, pushing blocks of rocks in the subduction zones of the plates, the forces of resistance in the collision at the edges of the converging plates, such as Trinidad or the Himalayas, the forces acting along the transform shifts, where plates move side by side with each other (for example, the San Andreas fault in California), and absorption over the subduction zones (northeast Australia).

Another source of stress in the earth's thicker associated with the so-called topographic loads caused by large mountain ranges, such as the canadian Rocky mountains or the Himalayas, increasing or removing loads due to ice cover, or changes in sea level. This category otnosyashchayasya load, for example associated with sedimentation in the basins, and the descending volume of load within the active sedimentary complexes.

Another category of sources of stress in the earth is thicker lithostatic buoyancy. Due to the fact that the density of the lithosphere is lower than its underlying asthenosphere, it "floats" on the underlying substance, and sedimentation load and gradient changes in the thickness or density of the lithosphere can lead to bending forces. Voltage of the other categories, causing flexure curves, are formed due to localized topographic loads and forces acting on the descending slabs in subduction zones. Finally, earthquakes (offset reset), active volcanism and salt diapirism are all examples of processes that lead to changes in local stresses.

From all the above categories stresses the main contribution to the stress field in the area of natural occurrence contribute forces responsible for the movement of tectonic plates, and gravity load. These forces result in the movement of lithospheric plates that form the crust of the earth. The force of gravity loads include topographic loads and loads caused by the density gradient and the buoyancy of the lithosphere. They can mutate under the influence of the local manifestations of such a process is in, as volcanism, earthquakes (vertical offset) and salt diapirism. Human activities such as mining and extraction or injection of fluids, may also cause local changes in stress.

Because the components that make the greatest contribution to the stress field (gravitational load and voltage when tectonic movements of the plates), there are large spaces, the orientation and magnitude of stresses in the earth's crust differ noticeable regularity. However, when using geomechanical analysis in drilling and engineering fields important to consider local perturbations, both natural and anthropogenic origin. There are countless examples of real regions where the orientation of the individual stresses within the field exactly the same, but the voltage varies systematically between the individual fields. Specialists in this field it is also known that the voltage can be different within different geological layers or different tectonic areas of the earth's crust and neighbouring local sources of disturbance voltages can be varied by changing coordinates literally through each foot.

The vertical stress can be the maximum, intermediate or the minimum principal stress. For descriptions of these three possibilities is used a classification scheme based on the type of reset that occurs in each case. Table 1 shows the definition of a maximum (S1) and minimum (S3) principal stresses for different types of discharges.

TABLE 1
RESETS1S3
NormalSVSHmin
Horizontal offsetSHmaxSHmin
ReverseSHmaxSV

Under normal reset maximum is the vertical stress. If the vertical stress is the intermediate, this indicates the horizontal offset reset. If the vertical stress is the minimum, the reset is defined as the reverse. At a given depth of the horizontal stress will be the least under normal reset anymore when shifted horizontally, and the highest is in a reverse reset. Typically, the vertical hole, ocas which are all less stable during the transition from the normal reset through horizontally shifted to reverse and therefore require the drilling fluid of greater density during drilling operations.

Specialists in this field it is known that in many cases it is desirable to drill wells in specific areas, focusing on the in-situ stress, existing along the trajectory of the wellbore. In particular, the planning of the borehole trajectory in a particular direction with regard to the existing in-situ stress field or in a specific geological horizon, selected on the basis of stress analysis, can greatly improve (and degrade) the parameters of the finished hole. Regarding the latter case, it is well known that a transaction is well within the horizon with low voltage can increase the efficiency of hydraulic fracturing (fracking), as well as its effectiveness in relation to the volume extracted or injected fluid. This is partly due to the fact that in the case of low values of voltages to generate cracks by injection of fluid requires a relatively low pressure, and partly because at low values of voltage easier to maintain the required disclosure crack and rheological parameters during well operation.

Further, it is well known that the orientation of the well, taking into account stresses may also improve or worsen the efficiency of completion when using other methods, such as first cu is the accumulation of casing pipes, and then perforating the casing in the hole for connection of the latter with the reservoir full of fluid. The orientation of the well, taking into account stress can also have an impact on costs in relation to the assembled structures necessary to achieve the goals set during the drilling of wells. These goals are discussed in detail in the patent US 7181380, M. dusterhoft chief (Dusterhoft) and others, the assignee of which is the same person as the present invention, the content of which is incorporated into this description by reference. As follows from the above-mentioned application, information obtained from simulation of hydrocarbon production in the reduction of the pore pressure, stress values and orientation, and strength of rocks, is used to determine the optimal project completion, including the selection of the type of completion, the trajectory and the coordinates. In addition, the process can also be considered possible mechanisms of occurrence of accidents, to determine the requirements for completion and their influence on the selection of the completion.

Example benefits from the optimal orientation of the borehole trajectory, taking into account the stresses can serve as a case collector with natural fractures. In this case, the rheological characteristics of natural fractures (which can byteoriented arbitrary or parallel) depending on their orientation relative to the principal stresses. In many cases, the highest permeability among cracks in rocks has their subsystem with the optimal orientation for displacement under the influence of the stress field. In any case, the orientation of the natural fractures is most likely permeability (optimally oriented fractures) can be identified, if known, the orientation and the magnitude of the stresses. Because wells drilled perpendicular to the optimally oriented fractures that intersect the largest number of these cracks and, thus, they correspond to the highest probability of maximum coupling of fluid flow with these cracks, there is a choice - simply due to the availability of information on the magnitude and orientation of stresses - the best orientation of the wells to maximize fluid flow between the well and the natural cracks in the rock.

In many cases, maximizing productivity or injectivity requires maximizing natural cracks. In other cases, it is preferable to minimize communication with the permeable cracks. Well that solved the last problem, have an orientation, which can also be calculated by known methods, but only if a known orientation and the magnitude of the stresses. Since the voltage change with a change of location is ogene, it is advisable to have in each case the method of determining stresses and their orientation during drilling and to be able to change the orientation of the borehole when changing voltages. Knowledge of the stresses and their orientation allows foot by foot to determine in probatively well the extent of its connection with natural permeable cracks, which, in turn, provides in each case, the choice of the best points perforations in cased wells with operational profile column.

Another example of the advantages of optimizing the orientation of the borehole is the case when the well must be terminated by stimulation with the use of hydraulic fracturing. It is known that the crack propagated in the majority of rocks in the areas where they are perpendicular to the least principal stress. Therefore, when stimulation through hydraulic fracturing in wells drilled parallel to the least principal stress (SHmin), will be obtained cracks perpendicular to the axis of the borehole. In cased wells with profile production column selective perforation through discrete intervals and selective stimulation of each interval separately will lead to the formation of a number of parallel cracks, radially extending outwards from the borehole. In particular the military circumstances it is optimal for the effective achievement of the maximum flow rate on the Deposit (or, in the case of the so-called absorbing wells for maximum pick-up order injection of reservoir water). In other cases, it is desirable to drill the hole so that the intensification of the flow through hydraulic fracturing was formed only crack located along the axis of the borehole. In this case, it is desirable to drill a borehole parallel to the intermediate or maximum principal stress. If the orientation of the drilled wells only slightly deviates from this optimal orientation, these wells will be much harder to stimulate, and the geometry of cracks in them will differ considerably from the desired. Since the voltage change with location, it is desirable to have detailed information (for example, foot by foot) about the local orientation of the stress field to perform in order to achieve the desired result, selective stimulation of only where well the best way is oriented relative to the local stress field.

Although these and other advantages of the optimal orientation of the boreholes relative stress fields known to specialists in this field, there is an unmet need for improved methods by which you can Orient the trunks of wells so the m optimal way.

Disclosure of inventions

One of the objects of the present invention is a method of evaluation of reservoir rocks.

The method includes shipping (descent) BHA (BHA) into a borehole, measurements, reflecting the tension in the reservoir during rotation of the BHA, using the results of measurements, depending on stress formation, to estimate the azimuthal variation of stresses in the layer and change any of the settings mode for drilling BHA based on the evaluation of the azimuthal variation of stresses in the layer.

Another object of the invention is a system for the evaluation of reservoir rocks. This system includes the layout of the bottom hole Assembly (BHA)configured with delivery into the well, the module with sensors mounted on the BHA for measurements, reflecting the tension in the reservoir during rotation of the BHA, and at least one processor is configured to use measurements that reflect stress in the reservoir, to assess the azimuthal variation of stresses in the layer and change any of the settings mode for drilling BHA based on the evaluation of the azimuthal variation of stresses in the layer.

Another object of the invention is a machine-readable medium accessible to the processor (for direct participation in its work) and includes teams who, allowing for the performance of their processor to use a measurement that reflects the voltage in the reservoir, to assess the azimuthal variation of stresses in the layer, and change any of the settings mode for drilling BHA based on the evaluation of the azimuthal variation of stresses in the layer.

Brief description of drawings

The above and other characteristics and features of the present invention will be better understood from the detailed description of specific embodiments of the invention in conjunction with the attached drawings on which is shown:

figa - schematic illustration of the determination of the stress tensor S in an arbitrary system of Cartesian coordinates,

figb is an illustration of the transformation tensor corresponding to the rotation axes of the system, presented at Figo,

figw - schematic illustration of the definition of the tensor principal stresses S' in Cartesian coordinates, including the maximum (S1), intermediate (S2) and minimum (S3) main voltage

figure 2 is a block diagram illustrating a preferred methodology for the practical implementation of the present invention,

figure 3 - schematic illustration of a drilling system suitable for use with the present invention,

figure 4 is an illustration of the matching of the ellipse with the experimental points,

5 - depending settled between the maximum principal stress and artificially educated tension cracks in the layer,

figa is an example of an acoustic imaging of the wall of the well bore,

figb is an example of visualization of a wall of a wellbore according to logging resistance

7 - analysis of wood thrown on the section of the wellbore, where the angle of the end face of the drilling tool is within the zone of fall,

Fig - analysis of wood thrown on the section of the wellbore, where the angle of the end face of the drilling tool is outside fall,

Fig.9 - wellbore weakened by stress,

figure 10 - simulated picture of the distribution of stresses and breaks in the horizontal wellbore drilled parallel to the direction of maximum horizontal stress,

11 - simulated picture of the distribution of stresses and breaks in a horizontal wellbore, when the azimuth of the maximum horizontal stress at 10° greater than the azimuth of the wellbore

Fig - simulated picture of the distribution of stresses and breaks in a horizontal wellbore, when the azimuth of the maximum horizontal stress at 5° less than the azimuth of the wellbore.

The implementation of the invention

Figure 2 shows a block diagram illustrating geomechanical the correction of the direction of the wellbore in accordance with one embodiments of the invention. As shown in figure 2, data layer in the region of dedalena to be drilled borehole, can be received and processed (270) to create a preliminary model for the stress in this region. In an alternative embodiment of the invention information about the stress field can be obtained during drilling operations, as discussed below.

In some cases, may be conducted prior to drilling, so that may have some a priori information on the basis of which it is possible to simulate, at least preliminarily, the stress field in the region. Alternatively or in addition in the region can be carried out drilling of one or more peripheral or pilot wells to obtain data through measurements during and/or after drilling using the selected devices, examples of which are too numerous to list in this description. From these measurement data can be obtained voltages within a given region.

In many cases such an experienced well may be a simple hole with a vertical stem. In practice, the oil and gas industry frequently perform drilling experienced or peripheral wells to the implementation of directional drilling, although, as mentioned above, it is not essential for an effective and useful application of the present invention in practice./p>

According to figure 2 operation begins drilling. Detailed description of the drilling system is provided below. Information about the stress field can be obtained using measurement while drilling. Measurement data in real time during the drilling process are processed to obtain a model of stress in real time (274). After this is accomplished through control of the drilling system to obtain the desired trajectory and achieve pre-defined goals. Below are discussed in detail drilling system.

Next, figure 3 presents a schematic representation of the drilling system 300, applicable in various illustrative embodiments of the invention. A drilling system 300 includes a drill string 320, carrying the drill layout 390 (also referred to as the layout of the bottom of the drill string, or "BHA"), descent vehicle what is used in the well bore 326, probatively in the rock mass 395. A drilling system 300 may include conventional oil rig 311 mounted on the floor 312, which may rely on the table of the rotor 314, which can rotate the primary engine, for example an electric motor (not shown), with the required speed. Drill column 320 may include tubing (tubing), such as drill pipe 322, or coiled tubing (flexible tubing - coiled tubing)extending from the top of the spine in the bore 326. Drill string 320 can be pushed into the well bore 326 when using drill pipe 322 as tubing. When using coiled tubing may be, however, used a feeder (not shown) in the well bore 326 continuous columns coiled tubing with any drive, such as a drum (not shown). By the end of the drill string 320 can be attached drill bit 350, destroying rocks 395, when it rotates in the process of drilling a well bore 326. When using drill pipe 322 drill column 320 may be associated with the winch 330 through the leading drill pipe 321, swivel 328 and rope 329 on the pulley 323. In the course of drilling operations on the winch 330 may be regulated load on the drill bit 350, which is an important parameter affecting the mechanical speed of drilling in rocks 395. The winch 330 is well known to specialists in this field and therefore not described in detail.

During drilling operations in various illustrative embodiments of the invention may occur appropriate circulation of the drilling fluid 331 (known and/or also named as "drilling mud" or "washing fluid"), coming under pressure from the barn (source) 332 through the channel in the drill string 320 under the action of the mud pump 334. Drilling fluid 331 may pass from the drill the first pump 334 in a drill string 320 through a compensation of the hydraulic shock (not shown), the pipeline 338 and a leading drill pipe 321. Down to the bottom 351 of the well drilling fluid 331 can be fed through a hole (not shown) in the drill bit 350. Drilling fluid 331 can circulate up through the annular space 327 between the drillstring 320 and the well bore 326, walking back to the barn 332 through the return pipe 335. Drilling fluid 331 can lubricate the drill bit 350 and/or the removal of the last fragments of drilling cuttings and/or drill cuttings present in the well bore 326. The sensor S1consumption and/or dynamic pressure of the drilling fluid 331 is usually located in the pipeline 338 and can provide information respectively about the consumption and/or dynamic pressure of the drilling fluid 331. Land measuring torque sensors (S2) and speed (S3associated with the drillstring 320 may provide information respectively about the torque and speed of rotation of the drill string 320. As a complement and/or alternative, can be used at least one sensor (not shown)associated with the rope 329 and showing the load on the hook of the drill string 320.

Drill bit 350 may rotate only when the rotation of the drill pipe 322. In other illustrative embodiments in the arrangement of the bottom of the drill string is (BHA) 390 to rotate the drill bit 350 may be placed downhole motor 355 (mud motor), and the rotation of the drill pipe 322 is usually in addition to torque downhole motor 355 (if necessary) and/or to perform changes in the direction of drilling. In various illustrative embodiments, the implementation of electricity can be provided by the power supply unit 378, which may include sub with batteries and/or electric generator and/or inverter that generates electricity using a turbine connected to a generator and/or inverter and/or leading them in motion. Measurement and/or control the amount of electric power at the generator output, is included in the power supply unit 378 may provide information about the flow of the drilling fluid (mud) 331.

Downhole motor 355 may be associated with the drill bit 350 via a drive shaft (not shown), housed in a bearing unit 357. When drilling fluid 331 passes under pressure through the downhole motor 355, the latter may rotate drill bit 350. Bearing unit 357 can withstand radial and/or axial load on the drill bit 350. The stabilizer 358 may be associated with a bearing unit 357, acting as a centralizer for the lowest part of the downhole motor 355 and/or BHA (BHA) 390.

Next to the drill bit 350 may be located sensor module 359. The module is tchikov 359 may contain sensors, circuits and/or software for receiving and processing data about dynamic drilling parameters. These dynamic parameters are usually jumping on the drill bit 350 on the bottom, intermittent supply BHA (BHA) 390, backward rotation, torque, shock, pressure in the wellbore and/or in the annular space, the acceleration and/or other measured parameters characterizing the state of the drill bit 350. As shown in the drawing, the layout of the bottom hole Assembly (BHA) 390 may also be provided for the sub telemetry and/or communication 372, which is used, for example, two-way telemetry. The sensor module 359 can handle the initial information from sensors and/or transmit the primary and/or processed information from sensors, for example, shown in the drawing, a ground control system 345 and/or the processor 340 via the telemetry system 372 and/or the inverter 343 associated with the pipeline 338.

The sub communication 372, power supply 378 and/or device for estimating parameters (OPP) 379, such as the appropriate instrument for measurement while drilling, can be combined with the drillstring 320. To activate the device, OPP 379 part of the BHA (bottom hole Assembly) 390 can be used, for example, flexible periodni is I. Such subs and/or devices OPP 379 can make the layout of the bottom hole Assembly (BHA) 390 between the drillstring 320 and the drill bit 350. The layout of the bottom hole Assembly (BHA) 390 may be implemented in the process of drilling a well bore 326 different dimensions, for example, electrical measurements, measurements on pulsed nuclear magnetic resonance (NMR) and/or nuclear density. In various illustrative embodiments, implementation of the layout of the bottom hole Assembly (BHA) 390 may include one or more sensors of the RPF and/or other devices and/or sensors 377, for example, one or more acoustic transducers and/or acoustic detectors and/or acoustic receivers a capable, in the process of drilling, measure the distance from the center of the downhole tool OPP 379 to different points on the surface of the well bore 326, and/or one or more mechanical or acoustic cavernomas 377b.

Mechanical cavernomas can contain multiple radially spaced probes, each of the radially spaced probes may participate in the measurement of the distance from the center of the downhole tool OPP 379 to various points on the wall of the well bore 326, for example in the drilling process. Acoustic cavernomas may include one or more acoustic transducers, the forehand is the corresponding acoustic signals in the downhole fluid, and measuring the time between their emission and return after reflection from the wall of the wellbore. In one embodiment of the invention, the transducer emits a collimated beam of acoustic radiation, so that the received signal can represent the energy scattered in the areas of collision of the beam with the wall of the wellbore. In this respect, measurement of acoustic cavernarum similar to measurements made using mechanical cavernoma. The following discussion of the invention based on this design.

In one of alternative embodiments of the invention the acoustic transducer can emit a beam with wide angle coverage. In this case, the signal received by the transducer may be a mirror image of the acoustic beam from the wall of the wellbore. For such cavernoma you want to modify the method of analysis described below.

Further, the sub communication 372, shown in figure 3, can receive signals and/or measurement data, and to transmit signals, for example using two-way telemetry, for processing by the ground control system and/or processor 340 and/or other ground-based processor (not shown). As an alternative and/or Supplement the signals can be processed in the well using, for example, the downhole processor 377c in the layout of the bottom hole Assembly (BHA) 390.

Nasamnatam management and/or the processor 340 may also receive signals from one or more other sensors and/or devices and/or signals from the sensor of the flow rate of the drilling fluid (S 1), surface torque sensor (S2and/or ground-based sensor speed (S3and/or other sensors used in the drilling system 300, and/or may process these signals in accordance with programmed commands provided in the ground control system and/or processor 340. Ground control system and/or the processor 340 may display the desired drilling parameters and/or other information on the display/monitor 342, which can be used by the operator (not shown) to control the drilling operations. Ground control system and/or the processor 340 may generally include a computer and/or the processing system based on a microprocessor, at least one storage device for storing programs and/or models and/or data recording device for recording data and/or other peripherals. In the ground control system and/or processor 340 typically provides a device alarm 344, are activated if any dangerous and/or undesirable conditions in the process.

In the present invention may be used various ways of determining the principal stresses in the rock mass. In one of the methods of measurements made with acoustic cavernoma, part of the BHA are used dlawrence shape of the wellbore, as well as the location of the BHA in the wellbore during drilling operations. The methodology used in the present invention, the assumption that the wellbore has an uneven surface, approximately and partially described by an ellipse (surface 400 figure 4). Center drilling tool is in position, marked as 455. A distance of 450 from the center of the drilling tool to the wall of the wellbore is measured by cavernarum during rotation of the drilling tool. In the example shown, the wall of the wellbore can be approximately described by two ellipses, denoted by 410 and 420. Large axes of the two ellipses are marked, respectively, by 451 and 465. Point 400a, 400b are typical points on the wall of the wellbore in which the distance is measured.

For the case when the drilling tool is in a fixed position in the center of a circular borehole, the wall of the wellbore can be represented by the equation:

(x-x0)2+(y-y0)2=R2(1),

where (x0, y0) - CCW is dinati center speaker cavernoma, a R is the radius. The distance R can be expressed as

R=r1=νΔt2(2),

where r1is the radius of the drilling tool, ν is the speed of sound in the borehole fluid, a Δt - time signal back and forth, the measured acoustic cavernarum. For mechanical cavernoma the second term in the right-hand side of equation (2) is simply the distance measured by cavernarum. Measure the distance R and angle θ determines the borehole wall in the polar coordinate system whose origin is at the center of the drilling tool.

Elliptical wellbore can be represented by the equation in the following form:

ax2+by2+cxy+dx+ey+f=0(3).

In real conditions, the center of the drilling tool is not in a fixed position, the measurement process through cavernoma exposed to noise, and the wall of the well bore is rough. The combination of all these factors makes it difficult to determine which of the actual displacement sensor for the estimation of reservoir parameters on the BHA from the wall of the wellbore. This problem is solved in the application Hassan (Hassan), the contents of which are incorporated into this description by reference. The method described in the application Hassan, includes evaluating the geometry of the wellbore by applying the least squares method to the measurement distance. Evaluation of the geometry of the wellbore may further include a drop dramatically different measurement values and/or definition of the virtual point where the measured values of the distances are limited divergence. This method may also include creating an image showing the distance to the wall of the wellbore. This method can also include creating a three-dimensional image of the wellbore showing the emptiness of leaching and/or defects in the casing. This method can further include using the estimated geometry of the wellbore to determine the speed of propagation of longitudinal waves in the fluid of the well. This method can, in particular, to include binning the measurements made by a sensor for the estimation of reservoir parameters.

An important point to be noted is that the geometry of the wellbore obtained in this way is characteristic of certain principal stresses in the reservoir rocks. Dependencies for the case when the wellbore and one of the main is atragene are vertical, presented in figure 5. Here is shown the cross-section of the wellbore 500. The North direction shown by 509 and maximum principal stress in the horizontal plane denoted by SHmax501. Under the action of the voltage form the borehole may be changed to elliptical in the direction 507. The actual amount of elastic deformation under the action of voltage is usually too small to be detected using cavernoma. However, in the direction 507 can be formed wood thrown, and in the direction 503 (near the minor axis 501 of the ellipse) - breaks. These wood thrown can be detected by measurement through cavernoma. Therefore, the direction of the maximum principal stress can be determined from the azimuth of wood thrown and/or breaks. This specific direction can then be used to control the direction of drilling, as discussed above. The stress value can be estimated on the basis of the strength of the rock formations. This is discussed in the application US 11/601950, Mooc (Moos), the assignee of which is the same entity as the present invention and the contents of which are incorporated into this description by reference.

On figa shows an example of acoustic imaging of the wall of the wellbore. The vertical axis represents depth, and the horizontal circumference of the wall of the wellbore deployed on p is Ascoli. In this particular example, the center of the image corresponds to the South. Image shows gaps 551, oriented at a 90° angle to the wood thrown 553. Noteworthy is the fact that wood thrown characterized by weaker signal (dark color)than the rest of the image, which indicates a smaller difference in the acoustic properties relative to the borehole fluid. A detailed analysis of wood thrown below.

Wood thrown and breaks (also called "cracks induced by drilling) can also be seen in other images of the wall of the wellbore. For example, on fig.6b presents a sample visualization of a wall of a wellbore according to logging resistance. The image obtained using logging microprobe resistance. Gaps identified through 561, and the wood thrown through 563. Thus, images obtained by logging resistance, can be used to determine the directions of the principal stresses. It should be noted that the image of another type, for example obtained by logging density, also showing cracks formed as a result of wood thrown and breaks, and therefore can be used to determine the directions of the principal stresses.

7 shows the analysis of wood thrown on the walls of a typical wellbore. Points connected by line 601, presented Aut angle end of the BHA as a function of depth. In the context of the present description, the angle of the end face is determined by the orientation of the reference mark on the BHA. The orientation of the BHA can be determined using a magnetometer or gyroscope. The horizontal lines marked through 603, show intervals of wood thrown measured in the wellbore (corresponding to the width of the dark areas figure 6). It is seen that the angle of the end face of the drilling tool falls within the zone of fall throughout the depicted area. Another part of the same wellbore shown in Fig. It is evident that the angles of the edge, denoted by 701 are beyond fall 703. The difference between 7 and 8 is that drilling in the depth interval 7 was carried out by BHA, the end of which is selectively oriented in the direction of extension of the wellbore, which makes difficult the orientation of the barrel in any other direction. The result is obvious: in these circumstances, the borehole will be predominantly oriented in the direction of the wood thrown.

In contrast, drilling in the interval shown in Fig, were conducted using various BHA and with active control over the orientation of the wellbore. It is seen that in the presence of active management of the orientation of the wellbore becomes possible to overcome the natural tendency to passage of the wellbore in napravleniya (the direction of the minimum principal stress). Example layout for directional drilling is described in the patent US 7287604, Aronstam (Aronstam) and others, the holder of which is the same entity as the present invention, the content of which is incorporated into this description by reference.

It should further be noted that when in the wall of the well bore no wood thrown, trunk, apparently, can have a circular shape, however, it should be expected to reduce the amplitude of the reflected signal cavernoma, if some parts of the wall of the wellbore begin to flake off. This is schematically illustrated using figure 9, where all the well bore denoted by 801. The voltage causes the appearance of a weakened area defined by the area between the circle 801 and ellipse 803. The wellbore shown in the diagram using the locus of the first arrivals of the reflected waves, has, obviously, form 801, but reflections from site 807 will be weaker than from section 805 (see Fig.6). In addition, if the wellbore is displayed using the hodograph of the second arrival of the reflected waves, it turns out the form, denoted by 803. To determine the directions of the principal stresses in the present description to take account of changes in the amplitude of the reflected signal cavernoma.

In the example of the possible options being experienced vertical wells is in, then run the logs through electrocoating display device. Image analysis using the methods described above allows to detect induced by drilling the cracks in the walls, indicating a relatively constant direction of maximum horizontal stress. Then from experimental wells can be drilled lateral wellbore, the drilling of which is above the productive interval and which opens to the horizontal within the depth interval, experienced uncovered the well for which the obtained images discontinuous cracks of the walls, indicating the orientation of the maximum horizontal stress. The orientation of the sidetrack is chosen identical to the orientation of SHmaxidentified through analysis of wireline logs for vertical wells, so that when the frac cracks will be held along the axis of the wellbore. The situation with stress is that cracks are vertical (i.e. the value of Shminwill be less than the value of Sv). In other examples, the well may be drilled at an angle of 90° to the azimuth of SHmax to ensure the development of radial cracks perpendicular to the wellbore.

In the process of drilling horizontal wells are used downhole control drilling parameters to control Orient the AI of the well and its position in the manifold. To obtain real-time information about the gaps in the wall of the well also perform logging while drilling, diagrams which help to identify the orientation of the borehole relative to the principal stresses. The images are analyzed during drilling to detect induced characteristic features that occur at specific points around the circumference of the wellbore and, furthermore, formed under the bit because of excessive load on it and find out after proburivaya through them well. In some cases, gaps can be created deliberately in order to determine the voltage changing mode of drilling. An example is the increase in the speed of circulation for cooling of the wellbore to form gaps. Another example is the increase in the load on the bit to increase the probability of induced breaks under the bit. First, the images are identified discontinuous cracks 1003 in the wellbore 1001, oriented in the axial direction. Note that depicted in figure 10 the graph, the resulting rendering data logging resistance, x-axis angles the circumference of the wellbore, and the y - axis drilling depth. The stress analysis required to create these axial cracks, confirms that the well was drilled in the ol directions of principal stress and therefore, there is no need to change the azimuth of the well.

At some greater depth discontinuous cracks of the walls have the shape indicated through 1103 figure 11. For this model, the azimuth of the wellbore is 90°, and the azimuth of SHmax- 100°. On Fig shows breaking crack 1203, when the azimuth of the wellbore is equal to 100°, and the azimuth of SHmax- 95°. From this simulation it becomes clear when it is necessary to increase the angle of deflection, and when to reduce the latter to maintain the desired path.

At the end of the drill of the flight, you can produce images with higher resolution than allow visualization device through logging while drilling through the use of logging devices on the cable, re-entry horizontal wells by well known methods. For stimulation, you can choose the intervals, the images of which are manifested by cracks propagating in the axial direction, because in this case, stimulation requires the least pressure, and the most probable is the formation extending in the axial direction of the cracks, having good communication with the borehole. After this you can mount the well casing, and then perforating the casing at selected intervals in order to conduct hydraulic fracturing, avoiding, thus, is of tervalon, where the visualized data show that drilling occurs at a finite angle to the local direction of SHmaxand, consequently, the formation of hydraulic fractures will be more difficult and they will be worse associated with the wellbore.

This approach can be applied regardless of whether directed well or main voltage vertical or deviation from it, as well as in cases when the desired direction is parallel or inclined relative to any directions of the principal stresses at the site of occurrence of the breed, when characteristic features (structural elements)used to determine the orientation of the stress field relative to the wellbore, are wood thrown, discontinuous cracks or any other violation or when the orientation of the stress field is determined using other measurements, such as acoustic or electric. Below is a discussion of these alternative methods.

Specialists in this area known fundamental principle that the majority of the earth (rock) rock has elastic properties, which are functions of stress. In the absence of other influences, these rocks are less elastic in the direction that has the most compressive stress. Dipole probes offering the th logging stir in the borehole Flexural vibrations, which naturally divided into two independent waves in the case when the hole is drilled so that the stress acting on the edges differ from each other (for example, a vertical borehole in a formation with different horizontal stresses, so that SHmaxmore SHmin). One of these waves Flex well in the direction of greatest tension, which in the case of vertical wells is a SHmaxand the other Flex well in the direction of least stress, which in the case of vertical wells is a SHmin. Wave, bending the borehole in the direction of SHmaxmoves faster than the waves, bending the borehole in the direction of SHmin. By recording the orientation of the device and wells, conduct cross-dipole acoustic logging and subsequent analysis of the data register propagation using known methods, you can define the orientation of the maximum and minimum voltages by determining the directions in which two waves bend well. During cross-dipole logging measures the speed of transverse waves in a formation having two different polarization. In inclined or horizontal wells, the geometry is more complex, but this method is still applicable in many cases. This way is discussed in US patent 6098021, Tang (Tang) and others, the holder of which is the same entity as the present invention, the content of which is incorporated into this description by reference.

An alternative way of using acoustic data to determine the orientation of the stresses is the use of acoustic logging including azimuth. During this logging speed of propagation of acoustic waves along the surface of the wellbore, is recorded as a function of orientation. Due to local stress concentration, the speed of such acoustic waves is a function of the orientation along the wellbore. Because stress affects the speed of propagation of waves in the rock, there is the possibility to determine the orientation and relative magnitude of the stresses in situ by measuring the azimuthal dependence of the propagation velocity of acoustic waves.

Another way to determine the direction of the stresses in the rock mass are used to measure the electrical resistivity during multicomponent induction logging. This is described in the patent US 7359800, Rabinovich (Rabinovich) and others, the holder of which is the same entity as the present invention, the content of which is incorporated into this description by reference. In particular, the values of measurements of H xxHyyand Hxyare sensitive to the anisotropy of electrical resistivity, which can have several sources, including thin stratified layers and suites, as well as the crack - natural and induced drilling and hydraulic fracturing. It was found that even in the absence of cracks these measurements indicate the direction in which cracks would be formed, whether the voltage is more strong. It should also be noted that the direction of discontinuous fractures in the rock mass, determined by measuring the resistivity perpendicular to the direction of fall, so posting directional wells, probatively with the aim of intersection of these cracks may be carried out in the preferred direction even without control the azimuth of the wellbore.

Professionals in this field know that the principal stresses are not always vertical and horizontal, and that the stress field can rotate due to the presence of wells. If the effect of the presence of well significantly alter the magnitude and orientation of the local stress field in comparison with field stress away from the borehole, it is possible to analyze the measurements in the course of a multicomponent logging, apparent resistivity by induction probe with a large for the sake of the som research held by devices on the cable, and in the process of drilling, with the aim of determining the orientation of the stress field with transverse and biaxial anisotropy. In a thick layer of homogeneous anisotropic material, the appearance of discontinuous cracks determines the direction of anisotropy, which can be determined on the basis of data of multicomponent induction logging, which can be processed using, for example, multifrequency focusing to eliminate the influence of the borehole environment to determine the orientation of discontinuous cracks and, therefore, the conclusion conclusions about the orientation of the principal stresses in the remote field.

In layered media discontinuous cracks often oriented normally to the seams and are the source of biaxial anisotropy. The main directions of the biaxial anisotropy determined from measurements of the electrical resistivity in a multicomponent logging, where conclusions are made about the orientation directions of the principal stresses. This is discussed in US patent 7317991, Wang (Wang) and others, the holder of which is the same entity as the present invention, the content of which is incorporated into this description by reference.

To define the shape of the wellbore can also be used in the measurement method of radioactive logging. Use the of gamma logging is discussed in the application US 11/770209, Madigan (Madigan) and others, the owner of which is the same entity as the present invention and the contents of which are incorporated into this description by reference. According to the discussion held in the above-mentioned application using heuristic models for known values of the density of the drilling fluid and reservoir rock can determine the magnitude of the deflection device density gamma-gamma logging from the wall of the wellbore as a function of azimuth. This particular deviation can then be used in conjunction with the method of Hassan for making cartograms wall of the wellbore.

The analysis of measurements made in the borehole, may be performed downhole and/or surface processor. When used to analyze downhole processor becomes possible to control the direction of drilling essentially in real time, without the delays inherent in the system, transmitting telemetry information from the well and into the well. When the data management and processing refers to the use of the computer program, ensure the implementation of these operations and contained in a suitable machine-readable media, such as: a persistent storage device (ROM), programmable permanent memory (EPROM), electrically-erasable programmable constant is the authorized storage device (EEPROM), flash memory or an optical disk.

1. Method development of the reservoir rocks, including:
the stimulation voltage in the reservoir around the wellbore for education in it characteristic features associated with stimulated voltage;
measurements reflecting the geometry of the wellbore, using a BHA (BHA), rotated in the wellbore, the geometry of which shows the induced voltage in the reservoir;
creating an image of the borehole on the basis of measurements of its geometry;
estimation of azimuthal variations of the induced voltage in the reservoir at the depth of the well; and
change the mode setting for drilling BHA using estimates of azimuthal variations in the depth of the borehole induced voltage in the reservoir.

2. The method according to claim 1, wherein the parameter change mode includes drilling control the direction of drilling.

3. The method according to claim 1, wherein a measurement that reflects the geometry of the barrel, involves measuring the travel time of the acoustic signal from the BHA to the wall of the wellbore at different azimuthal orientations of the BHA, and when assessing the azimuthal variation in the depth of the wells stimulated voltage use of time passing at different azimuthal orientations of the BHA to assess the geometry with the ox wells and the location of the BHA in the wellbore.

4. The method according to claim 3, further including:
measurements of the amplitude of the acoustic signal reflected from the wall of the wellbore, and
using the amplitude of the reflected signal to detect a fall.

5. The method according to claim 1, wherein a measurement that reflects the geometry of the barrel, includes measuring a first velocity of the shear wave with the first polarization layer and measuring a second velocity of the shear wave from the second polarization in the layer.

6. The method according to claim 1, wherein a measurement that reflects the geometry of the barrel, includes measurements by the instrument multicomponent logging resistance in the wellbore at different azimuthal orientations of the BHA.

7. The method according to claim 1, wherein a measurement that reflects the geometry of the barrel, includes measurements using at least the device for logging by the method of resistance with visualization or device for density gamma-gamma logging.

8. The method according to claim 1, in which the estimation of azimuthal variations in the depth of the borehole induced voltage in the reservoir includes determining the direction of at least the maximum principal stress or the minimum principal stress.

9. The method of claim 8, where when you change the mode setting drilling using the difference between the direction of the wellbore and the direction of the receiving discontinuous cracks in the wellbore.

10. The system of evaluation of reservoir rocks, including:
a drill string made with the possibility of stimulating voltage in the reservoir directly from the borehole for education in the reservoir characteristic features associated with stimulated voltage;
the layout of the bottom hole Assembly (BHA)that is installed on the drill string;
module with sensors mounted on the BHA with measurements that reflect the geometry of the wellbore in the reservoir during rotation of the BHA, where the geometry of the wellbore displays a characteristic feature formed in the reservoir due to the induced therein a voltage; and
at least one processor configured to:
create an image of the borehole on the basis of measurements of its geometry,
evaluation azimuthal variations on the well depth induced voltage in the reservoir on the basis of the image, and
change the mode setting for drilling BHA using estimates of azimuthal variations in the depth of the borehole induced voltage in the reservoir.

11. The system of claim 10, in which the parameters of the drilling mode, changing at least one processor, include the direction of drilling.

12. The system of claim 10, in which the sensor module includes an acoustic site that is designed to measure the time passer is placed acoustic signal from the BHA to the wall of the wellbore at different azimuthal orientations of the BHA, and at least one processor configured to estimate azimuthal variations in the depth of the well is stimulated by a voltage by use of time passing at different azimuthal orientations of the BHA to assess the geometry of the wellbore and the location of the BHA in the wellbore.

13. System according to clause 12, in which the acoustic node with measurements of the amplitude of the acoustic signal reflected from the wall of the wellbore, and at least one processor configured to use the amplitude of the reflected signal to detect fall.

14. The system of claim 10, in which the sensor module includes an acoustic emitter that is designed to generate a first acoustic wave from the first polarization layer and the second acoustic wave from the second polarization layer, and at least one processor configured to use the velocity of the first acoustic wave and the velocity of the second acoustic waves to assess the azimuthal variation in the depth of the induced voltage.

15. The system of claim 10, in which the sensor module includes a device multicomponent logging resistance in the wellbore, intended for the measurement of resistivity in the reservoir at different azimuthal orientations of the BHA.

16. The system of claim 10, in which the sensor module includes at least a device for logging by the method of resistance with visualization, designed for measurements, giving an idea about the resistivity of the formation, or the device density gamma-gamma logging.

17. The system of claim 10, in which the at least one processor is configured to change the mode setting drilling by using the differences between the direction of the wellbore and the direction of the bursting cracks in the wellbore.

18. The system of claim 10, in which the at least one processor configured to estimate azimuthal variations on the well depth induced voltage in the reservoir by an additional direction for at least the maximum principal stress or the minimum principal stress.

19. Machine-readable medium accessible to the processor and includes commands that allow the processor:
to get a measurement that reflects the geometry of the wellbore in the reservoir, reflecting the voltage induced in the reservoir for the formation of it features and measurements obtained from sensors on the layout of the bottom hole Assembly (BHA) during its rotation;
to create an image of the borehole on the basis of measurements of its geometry;
assessment is to azimuthal variation on the well depth induced voltage in the reservoir based on the image; and
to change the mode setting of the drilling BHA using estimates of azimuthal variations in the depth of the borehole induced voltage in the reservoir.

20. Machine-readable medium according to claim 19, which represents at least one of the media which includes permanent memory (ROM), programmable permanent memory (EPROM), electrically erasable programmable read-only device (EEPROM), flash memory and optical drive.

21. Machine-readable medium according to claim 19, in which the above-mentioned additional commands allow the CPU to control the direction of drilling of the BHA.



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: by-pass system of oil well pumping unit for dual pumping of a well having at least two formations consists of Y-shaped unit installed at pipe string and pumping unit and string of bypass pipes with landing nipple for setting of removable blind plug are connected to the bottom part of this unit. Fishneck is located at setting of removable blind plug in the nipple in Y-shaped unit over the string of bypass pipes while the latter is fixed to the pumping unit by means of clams. Landing nipple is manufacture so that geophysical plug can be set in it instead of removable blind plug. In the well beneath by-pass system with pumping unit there are at least two packers of mechanical, hydromechanical or hydraulic action. Each packer is installed over respective well formation and at formation level between them there is at least one chamber with union or flow adjuster or stationary mandrel or pilot-controlled valve with hydraulic, electrical or mechanical actuation and ability to adjust flow passage with two positions of open and closed. Over the top packer there is pipe string disconnector at which adapter in disengaged status is installed. At the lower end of pipe string there is a blind plug or nipple-hopper. Besides geophysical plug can be set into landing nipple in by-pass of pumping unit instead of removable blind plug and nipple-hopper is fixed at the string of bypass pipes from the bottom. Upwards the latter the string of bypass pipes and pumping unit are interconnected by supporting structure. Telescopic sleeve is installed under the landing nipple at string of bypass pipes. Removable blind plug has sliding skirt in the upper part for pressure balancing and a tip in the lower part for wire or rope fixing. Bypassing method involves trip in hole of the tool at logging cable; the tool is installed at the logging cable with geophysical plug. Two hammers with frictional insert or inner surface with jagged notches are installed at the logging cable. The bottom hammer is installed 10-20 m higher then the tool. The top hammer is installed at bigger or equal distance from location point of geophysical plug in Y-shaped unit before the lower boundary of the surveyed formation. Geophysical plug is made with slide-off bushing in order to balance pressure.

EFFECT: improving operational reliability of downhole equipment during surveys of wells in production string downstream pumping unit due to accident-free removal of removable blind plug and geophysical plug in surveying process.

5 cl, 9 dwg

FIELD: oil and gas industry.

SUBSTANCE: tool contains sectional case with installed collar locators (CL), gamma-ray loggers (GRL), pressure sensors (P), temperature sensors (T), humidimeter (W), thermoconductive flowmeter (TCF) and resistivity metre (RM) from top downward; in pressurised portion of the case there are GRL, LM and P sensors at that sensitive membrane of P sensor is connected to environment by hydrochannel, while T sensors, W, TCF and RM are located in pressurised cavities of non-pressurised portion of the case. At that T and W sensors are shifted in relation to longitudinal axis of the device at equal distances and are installed in the case at place with two pairs of mutually perpendicular reach-through windows having different width and equipped with cross bulkheads, at that the device is equipped with flowmeter module consisting of centraliser, liner, body and metre run with RPM sensor and rotation direction sensor installed along axis of the body. In the upper part of the device there is also force sensing device, and between the device and flowmeter module there is an additional docking device with clamper and double-hinged mutually perpendicular electroconductive unit with offset of rotation axes in relation to longitudinal axis of the device; the device is equipped with additional three dimensional module or humidimeter (W) or thermal moisture tester (T-W) or viscometer (V).

EFFECT: improving operational performance of the device and expansion of its application area.

6 cl, 3 dwg

FIELD: oil and gas industry.

SUBSTANCE: method consists in emission of sounding pulses by means of a generator solenoid located inside tested pipes, the axis of which coincides with axis of the tested pipes, and measurement of EMF induced in receiving coils by means of an electromagnetic field decrease process. Magnetic flux is measured, which is caused by sounding pulses of the generator solenoid, by means of sensors located along the instrument perimetre at distance r from the probe axis, opposite the end face of the generator solenoid, in N sectors on radial direction.

EFFECT: enlarging application area and improving quality of pipe flaw detection.

10 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves arrangement of an fibre-optic cable in a production well; determination of well shaft temperature; build-up of a temperature vs. well depth graph; indication on the graph of a temperature rise minimum by 10 degrees, which is the closest one to the well head; determination of depth of well liquid level as corresponding to depth of the indicated temperature rise.

EFFECT: determination of liquid level in a well with high temperature for extraction of high-viscosity oil.

1 dwg

FIELD: measuring equipment.

SUBSTANCE: for determining the characteristics of pore volume and thermal conductivity of matrix of samples of porous materials, the sample of porous material is alternately saturated with at least two fluids with different known thermal conductivity. As at least one saturating fluid a mixture of fluids from at least two fluids with different known thermal conductivity is used. After each saturation of the sample the thermal conductivity of the saturated sample of the porous material is measured, and the characteristics of pore volume and thermal conductivity of the matrix of the sample of porous material is determined taking into account the results of thermal conductivity measurements.

EFFECT: increased accuracy and stability of determining the characteristics of the pore volume and the thermal conductivity of the test samples.

14 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: standard electric logging of a well is carried out in low-temperature rocks, the area of possible bedding of gas hydrates and hydrate formation is identified in them. In the identified area of low-temperature rocks, on the basis of data of standard electric logging, zones are registered, in which measured values of the apparent electric resistance of low-temperature rocks are equal to at least 15 Ohm.m. Coolant is pumped in the investigated rock interval, afterwards thermometry is realised using highly sensitive thermometers, providing for error of temperature measurements of not more than 0.01°C, and zones are sought for, rock temperature in which, relative to the lowest registered temperature in the identified zone is at least by 0.2-0.5°C lower than the temperature of rocks adjacent to the borders of the detected zones. At the same time the latter zones are considered as zones containing gas hydrates. The area of possible bedding and hydrate formation is the area of rock bedding characterised by availability of thermobaric conditions for gas hydrates existence in rocks.

EFFECT: its higher efficiency by detection of gas hydrate rocks bedded in low-temperature rocks below a foot of permafrost rocks.

3 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes delivery of a shank with a set of packers and unions, downhole geophysical multi-purpose device to the hole end at a logging cable. Pumping into the well of a fluid containing thermal- and neutron-contrasting agents and periodical measurements. Contrasting fluid is pumped by several portions with volumes not less than interior volume of the horizontal borehole by means of subsequent switching into operation of different boreholes intervals covered by packers, by means of opening and closure control of outlet connections. Oil is used as a contrasting fluid instead of water. Movement of the contrasting fluid through the borehole is monitored by gamma-ray modules, resistivity meter or thermoconductive flowmeter.

EFFECT: improving accuracy for determination of operating intervals and sources of flooding under conditions of horizontal wells operation.

5 cl, 6 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes acquisition of log data on depth and time for a well drilling by means of a well string; log data on depth and time including data related to factors of torsional and axial loads and data related to hydraulic factor; and determination of a drill string neutral point at the moment of drilling based on factors of torsional and axial loads and hydraulic factor.

EFFECT: determination of a drill string neutral point during well drilling.

20 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes simulating of formation and recording of data on borehole processes by a geophysical instrument run-in into the tubing string at a logging cable and self-contained instruments installed at the lower end of the tubing string. At that simulation of formation is made by breaking a breakable drain valve made of a brittle material of hemisphere shape and installed with a convex part downwards in the lower part of the tubing string; for this purpose a drill stem is fixed under the geophysical instrument and the geophysical instrument is run-in with the stem into the interval with speed sufficient to break the breakable drain valve. At that upper part of the tubing sting above the breakable drain valve is not filled with water and a packer is installed in tubular annulus at the level of the tubing string lower part.

EFFECT: increase of information content and reliability for borehole investigations; reduction of labour intensity, time consumption and equipment costs; possibility to use in wells with any producibility of the investigated formation.

1 dwg

FIELD: physics.

SUBSTANCE: electrodes are separately exposed to the impact of periodically accumulated potential energy of a spring, which is generated by rotating screw pairs and abrupt (impact) release of energy when screw interaction of crests of the screw pairs ceases. The apparatus for realising the method is a drive structure having an output shaft which actuates the screw pairs. During forward rotation, the screw pairs open centralisers and elastically press the electric leads to the wall of the well casing, apply periodic action on the electrodes that are rigidly connected to the electric leads. The electric leads are cut into the wall of the well casing. Impact action occurs when screw interaction between the screw and nut, which is pressed by a power spring, ceases.

EFFECT: improved electrical contact between electric leads and a casing column.

10 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: model is adapted to downhole conditions by means of its coefficients changing, calculation of optimal parameters and drilling of a well in optimal modes which is determined by minimum vibration frequency of drill pipe. The method envisages multiple coefficients updating for power law model by results of well measurements, calculation of optimal parameters of control against the criterion of maximum mechanical speed, performance of drilling at calculated parameters with optimum control against minimum vibration of the drill pipe. Besides drilling model the method uses flushing model for the purpose of even drilling and cleaning of wellbore from drill cuttings and also strata model characterising ability of formations for drilling.

EFFECT: increasing accuracy for control of drilling mode and increasing mechanical speed of hole making due to optimisation of control over minimum vibration of the drill pipe.

3 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes acquisition of log data on depth and time for a well drilling by means of a well string; log data on depth and time including data related to factors of torsional and axial loads and data related to hydraulic factor; and determination of a drill string neutral point at the moment of drilling based on factors of torsional and axial loads and hydraulic factor.

EFFECT: determination of a drill string neutral point during well drilling.

20 cl, 4 dwg

FIELD: mining.

SUBSTANCE: method to calculate instantaneous speed of drilling string assembly bottom rotation at a lower end of the drilling string, with a drive from a drilling mechanism on the upper end of the drilling string exposed to oscillations of sticking-slipping, having the rated or observed main frequency, besides, the method contains stages of detecting changes in a torque on a shaft of the drilling mechanism, combining the available torsion pliability of the drilling string with changes of the torque at the shaft and generation of an output signal, which represents instantaneous speed of rotation.

EFFECT: tuning of proportional-integral or proportional-integral-differential controller for damping of twisting waves energy at sticking-slipping frequency or near it.

15 cl, 15 dwg

FIELD: mining.

SUBSTANCE: method contains the following stages: (a) damping of sticking-slipping oscillations using a drilling mechanism above a drilling string, (b) control of drilling mechanism speed of rotation using a PI controller, (c) turning of a PI controller so that the drilling mechanism absorbs a larger part of twisting energy from the drilling string at the frequency of sticking-slipping oscillations or near it.

EFFECT: tuning of proportional-integral or proportional-integral-differential controller for damping of twisting waves energy at sticking-slipping frequency or near it.

21 cl, 8 dwg

FIELD: machine building.

SUBSTANCE: construction machine includes load-carrying plant, actuating device installed with possibility of adjusting the position relative to the load-carrying plant, at least one sensor to sense the position of supporting strut of mast, and at least one sensor to sense pulling force in auxiliary rope, and computing device provided with possibility of determining (based on the data of the above sensors) at least one adjustment range of actuating device, in which the actuating device can be adjusted at pre-specified stability of construction machine against turning over.

EFFECT: determination of overturning moment of construction machine and provision of stability of construction machine.

10 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves the following stages: obtaining the entry including the specified drilling trajectory to target location; determination of predicted location of equipment of drilling string bottom of drilling system at continuous drilling; comparison of predicted location of equipment of drilling string bottom with the specified drilling trajectory for determination of deviation value; creation of the changed drilling trajectory to target location, which is chosen based on deviation value from the specified drilling trajectory; automatic and electronic creation of one or several control signals of drilling device on the well surface to direct the equipment of drilling string bottom of drilling system to target location as per the changed drilling trajectory.

EFFECT: improved control of equipment of drilling string bottom, which leads to improved response of equipment of drilling string bottom and quicker operation of equipment of drilling string bottom.

21 cl, 11 dwg

FIELD: oil and gas production.

SUBSTANCE: proposed method comprises adjusting and maintaining optimum differential pressure by defining and adjusting flushing fluid density, allowing fro mechanical rate of boring depending on formation drillability index. In compliance with proposed method, drilling parameters are controlled directly at well bottom. Here, adjusted are differential pressure above screw device bit and flushing fluid density by mounting separator there above. Note here that all components feature equal diameter while drilling rate is optimised by calculation of drilling parameters. The latter include bit rpm, load on bit, flushing fluid flow rate to be defined from mathematical expressions. Besides, drilling string bottom comprises bit, sludge trap and drilling tubes. In compliance with this invention, screw device and separator are mounted above the bit. Note here that diameter of external generator of screw, separator and other components should be equal.

EFFECT: higher efficiency of rock breaking.

2 cl, 1 dwg

FIELD: oil-and-gas production.

SUBSTANCE: invention relates to tool for geotechnical measures as, for example: fitting or removing plug, valve opening/closing, tube cutting and borehole cleaning. Proposed tool 100 comprises unit arranged on well-logging cable to work at well bottom and electric drive 40 connected with aforesaid unit to control it. Note here that proposed tool incorporates one or several transducers 25, 45, 65, 85 to measure, at least, one operating parameter of proposed unit. Also, this tool comprises linear actuator connected with drive and configured to displace the tool linearly and anchoring system connected with electric drive unit. Geotechnical parameters are optimised on the basis of, at least, one measured operating parameter.

EFFECT: monitoring of operating parameters.

36 cl, 3 dwg

FIELD: oil and gas production.

SUBSTANCE: method consists in creation of model that simulates operating mode of packed-hole assembly used for well bore drilling in drilling operation, performing drilling operation simulation with the use of model and random modification of drilling operation or packed-hole assembly on the base of simulation analysis.

EFFECT: increase of efficiency and output rate of drilling operation.

23 cl, 21 dwg

FIELD: oil and gas industry.

SUBSTANCE: automated system, which maintains preset density of drilling fluid prepared based on gaseous flushing agents and includes test equipment and remote monitors, contains also commutator, commutator of analogue-to-digital converter of computer interface card and variable speed drives for prompt control of flow of liquid or gas component of gaseous agents. Accuracy of control and responsiveness of the system is reached by use of digital form of transmission and processing of data with high accuracy of conversion. For this system density control is performed not by direct measurement but by calculation based on analytic dependences using data recorded by test equipment installed on transportation lines of foam preparation system. On-the-spot maintaining of required density of foam is performed using variable speed drives installed on compressor plant and pump for foam-forming fluid.

EFFECT: improving efficiency of control of properties of drilling fluid prepared based on gaseous flushing agents - foam solutions by means of accurate and prompt response of the system to its probable changes.

2 dwg

FIELD: mining industry.

SUBSTANCE: system includes mathematical model of drilling process in form of combined influence of conditions at pit-face and of drilling column operation. Model of drilling process is constantly renewed by results of well measurements performed during drilling operation. On basis of renewed drilling process model a set of optimal drilling parameters is determined and sent to system for controlling surface equipment. Also, system allows surface equipment control system to automatically adjust current control sets for surface equipment on basis of renewed optimal drilling parameters. Different control scenarios are generated and executed for transferring data to surface equipment control system on basis of current drilling mode.

EFFECT: optimized operation.

2 cl, 7 dwg

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