Facility and procedure for estimation of oil reservoir

FIELD: oil and gas industry.

SUBSTANCE: invention refers to well survey, particularly to procedures of underground reservoir estimation by means of downhole instrument. For this purpose a viscosity gage-densimetre for a downhole tool is arranged in well borehole drilled through an underground reservoir. The downhole tool is designed for supply of at least a portion of reservoir fluid into the viscosity metre-densimetre. The viscosity metre-densimetre consists of a sensitive block and of a design diagram for calculation of at least two parametres of fluid, notably, viscosity and density. The sensitive block is located inside the downhole tool and contains at least two distanced in space connectors, a string suspended with tension between the connectors, and at least one magnet generating magnetic field interacting with the string. The string interacts with reservoir fluid when the viscosity metre-densimetre is inserted inside the downhole tool, and the downhole tool is located in the underground reservoir and intakes fluid from the underground reservoir. The connectors and the string are made out of materials with similar ratios of heat expansion and form a frequency oscillator.

EFFECT: increased reliability of device operation in well; upgraded accuracy of measuring parametres of reservoir in well.

18 cl, 17 dwg

 

The technical field to which the invention relates.

The present invention relates to a method of evaluating a subterranean formation through a downhole tool located in a wellbore through a subterranean formation. More specifically, but without limitation, the present invention relates to methods for determining the parameters of the fluid such as viscosity and density of the formation fluid flowing in the downhole tool and/or measured by the downhole tool.

The level of technology

Wells are drilled for the discovery and production of hydrocarbons. Downhole drilling tool with a chisel on the end deepen into the ground for the formation of the wellbore. Advancing the drilling tool through the drill tool pumped drilling mud and let it out on the drill bit to cool the drilling tool and the removal of debris drilling. In addition, the drilling fluid forms a mud cake, which lines the well bore.

During drilling operations it is desirable to perform various evaluations of formations penetrated by the wellbore. In some cases, the drilling tool can be removed, and the descent on the cable, the tool can be deployed in the wellbore for investigation and/or sampling from the reservoir. In other cases, the drilling tool may be provided with devices which mi for investigation and/or sampling of the surrounding layer, and drilling tools can be used for research or sampling. These samples or test results can be used, for example, to determine the location of large hydrocarbon deposits.

For evaluation of the formation often requires that the reservoir fluid extracted in the downhole tool for investigation and/or sampling. Various devices, such as probes, are from the downhole tool for establishing messages fluid reservoir surrounding the wellbore, and to extract the fluid in the downhole tool. A typical probe is a circular element, acting on the downhole tool and the opposite side wall of the wellbore. Rubber packer on the end of a probe is used to create a seal with the wall of the wellbore. Another device used to form a seal with the wellbore, known as the dual packer. In the case of the double packer two elastomeric rings extend to radii around the tool to isolate the portion of the wellbore between them. Rings form a seal with the wall of the wellbore and provide the ability to extract fluid in the isolated portion of the wellbore and into the inlet hole in the downhole tool.

Clay crust, lining the wellbore, it is often useful to have the latania probe and/or dual packers with the wall of the wellbore. After sealing the reservoir fluid extract in the downhole tool through the inlet opening by lowering the pressure in the downhole tool. Examples of probes and/or packers, used in downhole tools are described in U.S. patents№№6301959, 4860581, 4936139, 6585045, 6609568 and 6719049 and in the application for U.S. patent No. 2004/0000433.

Evaluation of the reservoir is usually performed on the fluids taken in the downhole tool. Currently there are ways to perform a variety of measurements, preliminary studies and/or sampling fluids, which are included in the downhole tool. However, it was found that when the layer of fluid included in the downhole tool, various pollutants, such as borehole fluid and/or drilling fluid can enter into the tool along with formation fluids. These pollutants can affect the quality of the measurements and/or samples of reservoir fluids. Moreover, the pollution may be the cause of costly delays in the operation of the wells due to the need for more time for incremental research and/or sampling. In addition, such problems can lead to erroneous results that are false and/or useless.

Therefore, to obtain reliable readings, it is desirable that the layer of fluid that is included in the downhole tool, was dostat is a rule of "clean". In other words, wireline fluid should have low pollution or not to have it. Attempts have been made to eliminate the occurrence of pollutants in the downhole tool together with the reservoir fluid. For example, as described in U.S. patent No. 4951749, to prevent entry of contaminants into the downhole tool with the formation fluid in the probe set filters. In addition, as described in U.S. patent No. 6301959 probe provide a protective ring for separating the contaminated fluid from the clean fluid when it enters the probe. The fluid included in the downhole tool, generally passes through the bypass line and can be captured from the selected camera or dropped into the wellbore. Various valves, measuring devices and other components can be included throughout the drainage lines to reject, research, and/or seizure of fluid when it passes through the downhole tool.

The fluid flowing through the downhole tool may be analyzed to determine various downhole parameters or properties. Thermophysical properties of hydrocarbon reservoir fluids, such as viscosity, density and phase behavior of fluids at reservoir conditions, can be used to estimate potential reserves, determination of flow in a porous medium, as well as for systems design completion, the division, processing and measurement.

Various methods have been developed to determine the viscosity of fluids. Viscometers having a weight suspended between the fixation points of the torsional thread, have also been proposed and described, for example, in U.S. patent No. 5763766 and 6070457. In addition, viscometers have been developed, formed of the vibrating elements. One such viscometer used in borehole apparatus for measuring viscosity, density and dielectric constant of formation fluid or filtrate in a hydrocarbon production well. For example, in published international application no WO 02/093126 revealed tuning fork resonator in a tube designed for real-time measurements and estimates of viscosity, density and dielectric constant of formation fluid or filtrate in a hydrocarbon production well. Another viscometer having a fixed string between two poles, used in laboratory conditions that are described in the publication “The viscosity of pressurized He above TλPhysica, 76, (1974), 177-180; “Vibrating wire viscometer”, The Review of Scientific Instruments, volume 35, No. 10 (October, 1964), str-1348.

The invention

The technical task of the present invention is to provide a device and method that provides viscosity measurements in the borehole, preferably, regardless of the provisions of the Oia downhole sensor relative to the gravitational field. It is desirable that such a system was able to provide validation to obtain repeatability and/or accuracy. It is also desirable that such a system had a simple configuration, designed for use in harsh downhole environment.

The task according to the present invention is solved by creating a viscometer-densimeter for a downhole tool positionable in a wellbore through a subterranean formation. The downhole tool is designed to transfer at least a portion of the fluid from the reservoir into the viscometer-densimeter. Viscometer-densimeter includes the sensing unit is positioned within the downhole tool. The sensing unit includes at least two spaced connector, string and at least one magnet. String suspended from a tension between at least two connectors so that the string is available for interaction with the fluid, when the viscometer is densimeter is located within the downhole tool and the downhole tool is located in the underground reservoir and receives fluid from an underground reservoir. The connectors and the string form of the frequency oscillator. At least one magnet creates a magnetic field that interacts with the string.

Connectors and string made of m is materials, having similar coefficients of thermal expansion to generate frequency oscillator. For example, the connectors and the string can be made of similar material to essentially eliminate variations of the resonant frequency of the string due to thermal and elastic deformation caused by downhole conditions. Viscometer-densimeter can also be equipped with an outlet tube in which the string is suspended by means of connectors, in this case, it is desirable that breather pipe, connectors, and the strings were made from materials having similar coefficients of thermal expansion to form a frequency oscillator.

Preferably the sensing unit is further provided with means to prevent rotation of the string with respect to the connectors. Means for preventing rotation of the string may include a sleeve that is attached to the string, and the sleeve has a non-circular cross-section.

Preferably viscometer-densimeter is further provided with a calculation circuit, receiving a response from the strings, to calculate at least two settings (e.g., viscosity and density) of the fluid interacting with the string.

According to another aspect of the present invention relates to a downhole tool for placement in the wellbore, with stink and passing through the underground reservoir. The layer usually contains a fluid, such as natural gas or oil. The downhole tool is provided with the housing, a device for fluid movement and viscometer-densimeter. The housing surrounds at least one of the evaluation cavity. Device for supplying fluid passes from the housing and forms a seal with the wall of the wellbore. Device for supplying fluid has at least one inlet opening that communicates with the evaluation cavity for receiving fluid from the reservoir and the fluid within the evaluation cavity. Viscometer-densimeter has sensitive unit, located within the evaluation cavity. The sensing unit provided with at least two spaced connectors, wire and a magnet. String suspended from a tension between at least two connectors, so that is ensured by its interaction with the fluid within the evaluation cavity. Connectors and string designed to generate a frequency oscillator. At least one magnet creates a magnetic field that interacts with the string. The viscometer can be any of the options discussed above.

Preferably, the downhole tool may be provided with a camera comparison containing fluid with known properties, such as viscosity and density. Downhole conditions, such as pressure and temperature inside the ameres compare similar (and preferably, identical downhole conditions within the evaluation cavity. The downhole tool also has sensitive block inside camera comparison, so that the downhole tool includes a sensing unit located in the fluid with unknown parameters estimated inside the cavity, and other sensitive block located in the fluid with known parameters inside the camera comparison. Then evaluate the signal indicating at least two unknown parameter of the fluid (e.g., viscosity and density) within the evaluation cavity.

According to another aspect of the present invention relates to a method for measuring at least two unknown parameters of the unknown fluid inside the wellbore through a formation containing a fluid. In this way the feeder fluids downhole tool is placed with the seal in the wall of the wellbore. Then the fluid removed from the reservoir and serves in the evaluation cavity within the downhole tool. The data of the fluid within the evaluation cavity are selected through a viscometer-densimeter with the string located within the evaluation cavity and suspended between the two connectors. The wire and connectors are designed for education frequency oscillator.

Preferably, the estimated cavity may be idler whether the Oia or the selected camera. In the case of data selected by viscometer-densimeter at least two parameters can be calculated by using the data taken within the evaluation cavity. These at least two parameters include viscosity and density.

The method may further comprise the step of selecting data relating to known fluid inside the chamber comparison with the temperature and pressure associated with the temperature and pressure of the fluid within the evaluation cavity. In this case, the method typically further includes the step of calculating at least two parameters of the unknown fluid within the evaluation cavity by using data taken from camera comparison, and data selected from the evaluation cavity.

In an additional aspect, the present invention relates to machine-readable medium, which may be either provided in the settlement scheme or included in the calculation scheme for the calculation of the at least two parameters of the fluid such as viscosity and density of the fluid. In this case, the machine-readable medium includes logic device for receiving a response from at least two sensor units, one sensing unit is located in the fluid with unknown parameters, and other sensitive block location is in fluid with known parameters, and calculating a signal indicating at least two unknown parameter of the fluid, which is one of the sensitive block, when in essence the exception of variations in the conditions of the wellbore surrounding the sensing unit in fluid with unknown parameters. Logic device to calculate the signal may include, for example, a logical device to perform a comprehensive treatment of the data received from the sensitive blocks.

In each of the aspects of the present invention described above, it is preferable that at least two parameters of the fluid was calculated at the same time.

Brief description of drawings

Further the present invention is illustrated by description of preferred embodiments with reference to the accompanying drawings, in which:

figure 1 depicts a schematic partial section view of the downhole descent on cable tool having an inner viscometer-densimeter, while the descent on the cable tool suspended from a rig;

figure 2 - section of the well with a downhole drilling tool having an inner viscometer-densimeter, while the downhole drilling tool suspended from a rig according to the invention;

figa - part of a downhole tool having a probe positioned opposite the side wall of the barrel is well, and viscometer-densimeter located within the estimated line in the downhole tool according to the invention;

figv another embodiment of a downhole tool having a clean discharge line, used in combination with a dual packer, according to the invention;

4 is a side view of the viscometer-densimeter located within the evaluation cavity, according to the invention;

5 is a cut-sensitive block viscometer-densimeter illustrating suspended from a string according to the invention;

6 is a General view of the spatial separation of the elements of the sensing unit viscometer-densimeter, shown in figure 4, according to the invention;

figa - block diagram of the operational sequence of the method for the simultaneous calculation of the viscosity and density according to the invention;

fig.7b - block diagram of the sequence of operations of another embodiment of a method for the simultaneous calculation of the viscosity and density according to the invention;

Fig - chart illustrating the surface characteristics of the Chi-square crossed by the hyperplane fixed values of f0illustrating at least used to calculate the density and viscosity according to the invention;

figure 9 is a General view of the spatial separation of elements other sensitive block viscometer-is encimera according to the invention;

figure 10 is a top view of the sensing unit shown in Fig.9, according to the invention;

11 is a side view of the sensing unit according to another variant of the invention;

Fig - sectional view of the sensor unit along the line XII-XII of figure 11 according to the invention;

Fig - diagram of the downhole tool having two or more viscometers-densitometer, one of viscometers-densitometer is located in the fluid with unknown viscosity and density, and the other viscometer-densimeter is in fluid of known viscosity and density, another variant embodiment;

figa - block diagram of the operational sequence of the method of simultaneous calculation of viscosity and density by using the construction shown in Fig, according to the invention;

fig.14b - block diagram of the sequence of operations of another method for the simultaneous calculation of the viscosity and density by using the construction shown in Fig, according to the invention.

A detailed description of the preferred embodiment variants of the invention

Definition

In the present description, certain terms are defined when they are first used, and some of the terms used in this description are defined below.

"The ring" for ring or to the formation of ring means, for example, line the floor of the su or design in the form of a closed curve, such as a circle or an ellipse.

"Contaminated fluid" means a fluid, such as gas or liquid, which is usually undesirable when the sampling and/or evaluation of the hydrocarbon fluid, since the fluid contains contaminants, such as mud filtrate used for drilling wells.

"Downhole tool" means instruments that are deployed in the wellbore, for example through the drill string, a wireline or columns flexible pipes to perform downhole operations associated with the evaluation, extraction and/or control one or more layers of interest.

"Functionally coupled" means directly or indirectly connected to transmit or pass information, force, energy, or substances (including fluids).

"Pure fluid" means an underground fluid, such as gas or liquid, which is sufficiently pure, original, relic or otherwise deemed acceptable degree representing a specific layer for selection of reliable sampling and/or evaluation of hydrocarbons in the sample fluid and the analysis of the field.

"Fluid" means either "pure fluid"or "contaminated fluid".

"Clip" means a device designed for compression or squeezing, or pressing two or more parts with each other is at the same time, so they gripped.

"Connector" means any device or host, such as a clamp for rigid connection or capture area of the string.

"Frequency oscillator means resonant frequency of a stretched string in vacuum (hereinafter referred to as "f0that is so predictable that changes in conditions in the wellbore, such as temperature and pressure, do not have a significant effect on the resonant frequency of a stretched string, resulting in the changing conditions in the wellbore data obtained on the basis of a stretched string, with an acceptable degree of accuracy are characteristics of the fluid interacting with a stretched string.

Figure 1 shows in the barrel 14 of the borehole of the downhole tool 10 according to the present invention is suspended from the drilling rig 12. The downhole tool 10 can be a tool of any type capable of performing the evaluation of the reservoir, such as a drilling tool, a tool for flexible tubing string or other downhole tool. In this case, the downhole tool 10 is a normal descent on the cable tool deployed from the rig 12 in the bore 14 of the borehole using a wireline 16 and located near the reservoir F. the Downhole tool 10 is equipped with a probe 8, designed to seal with the wall 20 of the barrel 14 wells (hereinafter "wall 20" or "wall 20 of the wellbore") and, as shown by the arrows, extracting fluid from the formation F into the downhole tool 10. Reference pistons 22 and 24 facilitate the pressing of the probe 18 of the downhole tool 10 to the wall 20 of the wellbore.

Figure 2 shows another example of the downhole tool 30 according to the present invention. In this embodiment, downhole tool 30 is a drilling tool which can be delivered in one or more (or may be delivered separately) of the drilling tool with measurement while drilling (IPA), the drilling tool with logging while drilling (PBC) or other drilling tool, which is known to specialists in this field of technology. The downhole tool 30 is attached to the drill string 32, driven drilling rig 12 for forming barrel 14 hole. The downhole tool 30 includes a probe 18, is arranged to seal with the wall 20 of the barrel 14 wells and used to extract fluid from the formation F into the downhole tool 30 (shown by arrows). Viscometer-densimeter or sensitive blocks, described below, can be used in the downhole tool 10 and the downhole tool 0.

On figa presents schematically a portion of the downhole tool 10 illustrating a system 34 for conveying fluid. Preferably, for entering into engagement with the wall 20 of the wellbore probe 18 protrudes from the housing 35 of the downhole tool 10. The probe 18 is equipped with a packer 36, designed to create a seal with the wall 20 of the wellbore. Packer 36 is in contact with the wall 20 of the wellbore to form a seal with clay 40 cortex lining the barrel 14 hole. Clay crust 40 seeps into the wall 20 of the wellbore and forming zone 42 penetration around the trunk 14 of the well. Area 42 penetration contains drilling mud and other downhole fluids that contaminate the surrounding layers, including the layer F and the plot is pure fluid 44 contained therein.

Preferably, the probe 18 has been provided with the estimated bypass line 46. Examples of devices that provide a fluid flow, such as probes and dual packers are used when removing the fluid in the discharge line are disclosed in U.S. patent No. 4860581 and 4936139.

Estimated delivery line 46 is held in the downhole tool 10 and is used for transmission of fluid, such as pure fluid 44 in the downhole tool 10 for investigation and/or sampling. Estimated delivery line 46 continues until the selected camera 50, designed to collect the item is about pure fluid 44. To eject fluid through the outlet line 46 can be used to pump 52.

Although figa shows the approximate configuration of the downhole tool used to extract fluid from the reservoir, specialists in the art should be understood that the invention is not limited to, can be used in different configurations of probes, drop lines and downhole tools.

On figv the scheme part of the downhole tool 10 according to other variant embodiments, equipped with a modified probe 18a and system 34a for supplying fluid designed to extract fluid in a separate discharge line. System 34a for fluid movement (pigv) is similar to the system 34 for movement of fluid (figa), except that the system 34a includes sewage treatment discharge line 46a in addition to the estimated bypass line 46 and pumps 52a and 52b associated with drainage lines 46 and 46a. The probe 18a (pigv) is similar to the probe 18 (figa), except that the probe 18a has two separate cavities 56a and 56b, and the cavity 56a communicates with the outlet line 46 and the cavity 56b communicates with the outlet line 46a. Cavity 56b is located around the cavity 56 so that the cavity 56b is extracted "contaminated fluid from the formation F to permit the extraction cavity 56a "touchpad the local fluid from the formation F. The contaminated fluid is discharged from cleaning the drain line 46a into the barrel 14 of the well through outlet 57. Examples, provides for the movement of fluids in devices such as probes and dual packers are used to extract fluid in a separate discharge lines described in U.S. patent No. 6719049, in published application U.S. No. 20040000433 and in U.S. patent No. 6301959.

According to the present invention viscometer-densimeter 60 (a, b, c) is associated with the evaluation cavity inside the downhole tool 10, for example with evaluative outlet line 46, cleaning the drain line 46a or selected by the camera 50, for measuring the viscosity of the fluid within the evaluation cavity. For clarity, figv viscometer-densimeter 60 marked positions 60a, 60b and 60 C. the Viscometer-densimeter 60 in more detail is shown in figure 4, 5 and 6.

Similarly, the downhole tool 30, as the downhole tool 10 (figa and 3B), can also contain a housing, a probe, a system for conveying fluid, packer, estimated discharge line, clean the discharge line, a sampling chamber, a pump (pumps) and viscometer-densimeter (viscometers-densitometer).

Viscometer-densimeter 60 will be described in detail below in the description of the evaluation cavity inside the estimated bypass line 46. However, it should be clear that the following description is equally applicable to the evaluation cavity inside of Estoi outlet line 46a or selected camera 50. Although viscometer-densimeter 60 will be described in conjunction with the downhole tool 10, such description is equally applicable to the downhole tool 30. Moreover, although the viscometer-densimeter 60 shown in figa and 3B are located along drainage lines 46 and 46a, but for measuring downhole parameters viscometer-densimeter 60 may be positioned in various locations relative to the downhole tool 10.

Viscometer-densimeter 60 (figure 4, 5, 6) has a sensing unit 62, one or more magnets 64 (a, b), the processor 66 signals and settlement scheme 68. In the example in figure 4 viscometer-densimeter 60 provided with two magnets 64A and 64b. The sensing unit 62 is provided with at least two spaced connectors 72 and string 74 (5), suspended between at least two connectors 72 so that the string 74 is available for interaction with the fluid, when the sensing unit 62 viscometer-densimeter 60 is located within the downhole tool 10 and the downhole tool 10 is in the subterranean formation F and receives fluid from the formation F. the Magnets 64A and 64b create a magnetic field that interacts with the sinusoidal current flowing through the string 74. The processor 66 of the signals is electrically connected with the string 74 via signal paths 75A and 75b. The signal paths 75A and 75b can be wired, ka is compulsory or air lines. The processor 66 provides signals to the excitation voltage, creating in the string 74 sinusoidal current, which usually causes the string 74 to vibrate or resonate in accordance with the signal applied to it. Typically, the signal applied to the string 74 with processor 66 signals, can be regarded as a signal sweep with a constant current, the frequency of the signal changes the specified image.

Calculation circuit 68 receives the response from the strings 74. Through the string 74 flows sinusoidal current, and when the frequency is close to the resonance frequency, is usually to fashion the lowest order, creates a find associated with the movement of the electromotive force ("EMF"). The excitation voltage and associated with the movement of the electromotive force is measured as a function of frequency above resonance. Usually calculation circuit 68 receives the response from the strings 74 indicating the resonant frequency of the string 74. The resonant frequency of the string 74 is changed in a predictable way depending on the viscosity of the fluid that provides the ability to determine the viscosity of the fluid. The manner in which the viscosity is determined by a response from the strings 74, will be discussed in more detail below. Calculation circuit 68 may be a scheme of any type capable of receiving a response from the strings 74 and to calculate the viscosity of the fluid. Usually calculation circuit 68 includes the process is R computer performing auxiliary program stored in a machine-readable medium such as storage device or disk, to enable calculation of viscosity calculation circuit 68. However, it should be understood that in some embodiments, the payment scheme 68 can be implemented through the use of analog devices or devices of other types. For example, to calculate the viscosity of the fluid calculation circuit 68 may include an analog-to-digital Converter followed by a decoder. Although figure 4 calculation circuit 68 and the processor 66 of the signals are shown separately, it should be clear that the calculation circuit 68 and the processor 66 signals can be implemented in a single circuit or implemented as separate circuits. In addition, although the calculation circuit 68 and the processor 66 of the signals shown in figure 4 inside the downhole tool 10, it should be clear that the processor 66 of the signals and/or calculation circuit 68 can be placed outside the downhole tool 10. For example, the processor 66 of the signals intended for the formation of the oscillating signal frequency, can be placed inside the downhole tool 10, while the calculation circuit 68 is placed outside of the barrel 14 wells in the control center, which is located at or near the stem 14 wells, or away from the shaft 4 of the well.

The sensing unit 62 viscometer-densimeter 60 also includes a housing 76. The housing 76 includes a channel 78 (figure 5 and 6), the inlet opening 80 that communicates with the channel 78, and the exhaust port 82 that communicates with the channel 78. Fluid flows (figure 4) estimated through the outlet line 46 in the direction 84. Therefore, when the fluid collides with the sensing unit 62, the fluid flows through the inlet 80 into the channel 78 and extends from the housing 76 through the outlet 82. When the external size of the case 76 is smaller in comparison with internal size estimated outlet line 46, a certain amount of fluid will also flow past the body 76 through the channel 87 (figure 4)formed between the outer surface 88 of the housing 76 and the inner surface 89 valuation outlet line 46.

String 74 is located in the channel 78 so that the fluid came in contact with essentially the entire string 74 between the connectors 72, when it passes through the housing 76. This ensures the flow of fluid along the length of the strings 74 between the connectors 72 for cleaning strings 74 between the fluids. String 74 is made of conductive material, is able to vibrate at multiple resonance frequencies of the main fashion (or its harmonics), depending on the tension of the strings 74 and the viscosity of the fluid surrounding the string 74. It is desirable to make the string 74 from a material having a greater density is here, because, the larger the difference between the density of the string 74 on the density of the fluid, the higher the sensitivity. String 74 must also have a high young's modulus to provide a stable resonance, and density provides sensitivity to the fluid around the strings through the relationship of the density of the fluid to the density of the strings. For the manufacture of strings 74 can be used a number of materials. For example, the string 74 may be made of tungsten or chromel. When the string 74 is used to measure properties of a gas, for example natural gas, it is preferable that the string 74 had a relatively smooth outer surface. In this case, chromel is the preferred material for the manufacture of strings 74.

As shown in figure 4, it is preferable that the magnets 64 are located on the outer side of the estimated bypass line 46 and is attached to the outer surface of the appraisal outlet line 46. In addition, the magnet 64 may be embedded in the housing 76. Alternatively, the housing 76 may be made of magnetic material.

The housing 76 (figure 5, 6) can be formed in the first body element 90 and the second housing element 92, which are combined to form the channel 78. It is preferable to make the first corpus element 90 and the second corpus element 92 of conductive non-magnetic material to mA the magnetic field, created by the magnets 64, could interact with the string 74 without significant interference from the housing 76. For example, the first corpus element 90 and the second corpus element 92 can be made of a material that is compatible with the conditions in the well, such as Monel K500, tungsten or non-magnetic material of another type, for example stainless steel.

The housing 76 is also provided with an insulating layer 96 (figure 5), located between the first body element 90 and the second housing element 92 to electrically isolate the first corpus element 90 from the second body element 92. String 74 is stretched between opposite sides of the insulating layer 96 for electrical connection of the first body element 90 with the second body element 92. An insulating layer 96 may be formed in the first insulating element 98 and the second insulating element 100. String 74 has a first end 102 and second end 104. The first insulating element 98 is adjacent to the first end 102 of the strings 74 and the second insulating element 100 adjacent to the second end 104 of the string 74. String 74 overlaps the channel 78 and serves for the electrical connection of the first body element 90 with the second body element 92.

In the sensing unit 62 (figure 4) each of the first body element 90 and the second body element 92 can be characterized by small, high is n as having a first end section 108, the second end section 110 and the middle portion 112 located between the first end section 108 and the second end section 110. The first end section 108 and the second end section 110 are the cross-sectional area or diameter that is smaller than the cross-sectional area or diameter of the middle section 112. Therefore, the first corpus element 90 and the second Cabinet element 92 has a shelf 114 separating the first end section 108 and the second end section 110 from the middle part 112. The inlet 80 and outlet 82 in the first case element 90 and the second case element 92 is formed directly on the ledges 114, so that the channel 78 passes through the middle portion 112 of the housing 76. For directing fluid to the inlet 80 ledges 114 have the proper form, shown in figure 4.

To connect signal paths 75A and 75b to sensitive block 62 viscometer-densimeter provided with a first clamp 116 attached to the first vessel element 90 and the second clamp 118 attached to the second vessel element 92. Therefore, the processor 66 signals and calculation circuit 68 are connected with the first and second terminals 116 and 118 via the signal paths 75A and 75b. It should be noted that the signal paths 75A and 75b are usually estimated through the outlet line 46 through one or more Proudnikov 120. Prohonice 120 create erotyczne seal for the fluid to pass signal paths 75A and 75b estimated through the outlet line 46 to prevent leakage of fluid through the openings, educated in the evaluation outlet line 46.

The first clamp 116 and the second clip 118 may be identical in construction and function. To implement the first clamp 116 and the second clamp 118, the first corpus element 90 and the second Cabinet element 92 may be provided with screw holes 124 formed on the first end section 108, and the second end section 110 of the first body element 90 and the second body element 92. Figure 5 the first corpus element 90 and the second Cabinet element 92 provided with screw holes formed on the first end section 108, and the second end section 110. As shown in Fig.4-6, the first clamp 116 and the second clamp 118 is also provided with threaded fasteners 126 to attach each of the signal paths 75A and 75b to the first vessel element 90 and the second vessel element 92.

The first corpus element 90 and the second corpus element 92 is connected by mechanical or chemical Assembly. Viscometer-densimeter 60 (6) is equipped with a large number of threaded fasteners 130, intended for attaching the first body element 90 to the second vessel element 92. It should be noted that the threaded fasteners 130 are typically made of conductive materials, such as steel or aluminum. In order to prevent the formation of R is siloviki fasteners 130 electrical paths between the first body element 90 and the second housing element 92, viscometer-densimeter 60 is also provided with a large number of insulating Proudnikov 132 to electrically isolate each of the threaded fasteners 130 from the respective first body element 90 or the second body element 92.

The sensing unit 62 viscometer-densimeter 60 may be secured within the estimated bypass line 46 using any suitable Assembly process. It should be clear that the sensing unit 62 shall be secured to prevent longitudinal movement and rotational movement within the estimated bypass line 46. It is preferable to give the signal paths 75A and 75b sufficient stiffness to prevent longitudinal and/or rotational movement of the sensing unit 62 within the estimated bypass line 46. To prevent displacement of the sensing unit 62 within the estimated bypass line 46 can also be used an additional means of fastening. For example, the estimated delivery line 46 can be narrowed downstream from the sensing unit 62, to prevent longitudinal displacement of the sensing unit 62 within the estimated bypass line 46.

The first corpus element 90 and the second corpus element 92 when docked with each other by threaded fasteners 130 interact with education is denitely 72. String 74 is attached and pull in the following way. First fix one end of the string 74. The other end is passed through the second connector 72, but do not pull. Mass (not shown) attached to one end, the speaker of the loose connector 72. The mass value, which hang on the string 74, within the Earth's gravitational field determines the tension on the diameter of the string and hence the resonant frequency. Resonance frequency of about 1 kHz can be obtained with a weight of 500 g hanging from a string with a diameter of 0.1 mm to change the range of the measured viscosity, it is possible to change the diameter of the string 74. After about 24 h the string 74 is clamped at the second end, and a mass delete. This procedure reduces the twisting of the string 74. Then the string 74 is heated and cooled, to obtain a string with the resonant frequency, which is quite stable between heat cycles. For viscometer-densimeter 60 it is necessary that the resonant frequency of the string 74 was stable during the time required to determine the integrated voltage as a function of frequency above resonance, which is about 60 C.

To calculate the viscosity, through the string 74 miss sinusoidal current in the presence of a magnetic field. The magnetic field is perpendicular to the string 74 and in the presence of sinusoidal current induces trono 74 to move. The resulting induced electromotive force (associated with movement EMF) or the integrated voltage is added to the excitation voltage. Associated with the movement of the electromotive force can be detected by calculation scheme 68 together with the signal processor, which includes a synchronous amplifiers, in which the excitation voltage may be removed or reduced to zero, or spectrum analyzers. String 74 resonates when the current frequency is close to or equal to the frequency of the main resonance. The integrated voltage is usually measured at frequencies above resonance, and the results of observations combined with the working equations, density and radius of the string to determine the viscosity of a fluid with a known density. The amount of current depends on the viscosity of the fluid, and change it so that by means of the detection schemes to obtain an acceptable signal-to-noise ratio. Usually use a value lower than 35 mA, and receive the result of the complex associated with the movement of the electromotive force component of a few microvolts. The diameter of the strings 74 also defines the upper limit of the working viscosity, i.e. with the increase of the diameter of the strings increases the upper limit of the working viscosity. There are other methods of excitation and detection of the movement of the strings, and not as comfortable as through the normal sync the local amplifier.

When calculating the viscosity and density of fluid on the response received from the strings 74, calculation circuit 68 operates as follows. String 74 is placed in a magnetic field and excite with the formation of the steady-state transverse vibrations by passing through it AC. The resulting voltage V developed on the string consists of two components:

The first member of the V1due to simply the electrical impedance of the fixed strings, while the second member of the V2due to the motion of the string in the presence of a magnetic field. V1is expressed as

In equation (2) f is the frequency at which the string 74 is excited in the presence of a magnetic field, whereas a, b, and C are adjustable parameters, which are determined by the regression relative to the experimental results. The parameters a, b and C accounted for electrical impedance strings and also campfires offset used in the synchronous amplifier in order to guarantee the detection voltage signal in perhaps a more sensitive area. The second component of V2is determined from the working equations of the tool in the form

where ∧ is the amplitude: f0resonance frequency of the string in a vacuum; Δ0internal dampfi the Finance strings; β - added mass due to fluid shifting string; β' damping due to viscosity of the fluid.

The mechanical properties of the vibrating string, which is detected attached weight β of the fluid and the viscous resistance of the β'can be represented in the form

and

where k and k' are defined as

and

In equations (6) and (7) a is a complex value that is specified in the form

where

In equation (8) K0and K1are the modified Bessel functions, and Ω is related to the Reynolds number characterizing the flow around a cylindrical strings or strings of radius R. In equation (9) viscosity and density of the fluid is defined as η and ρ, respectively. Therefore, the viscosity and density of the fluid can be determined by adjusting the values so that in-phase and quadrature voltage found from equations (1)-(9)were consistent with the experimentally found values within the interval based on the frequency. The frequency range within which the collected data is usually around fr±5g, where g is the half-width of the resonance curve, and frthe main often is and transverse resonance. Electrically perfect device, in which the ratio of signal to noise is high, and the electrical crosstalk, which increase with increasing frequency, equal to zero, the choice of bandwidth is not critical. However, he is critical in the case when Q{=f/(2g)} tends to unity, which occurs when the bandwidth increases, what happens to the increased viscosity, and, if the excitation current is not increased, followed by a corresponding decrease in signal to noise. The importance of determining the bandwidth within which measurements are performed, will become apparent below.

In equations (4) through (9) derived from the following assumptions: (1) the radius of the strings 74 compared with the length of the string 74, (2) the compressibility of the fluid is negligible, (3) the radius of the housing 76 containing fluid, compared with the radius of the strings, so that boundary effects are negligible, (4) the amplitude of oscillations is small. In a known viscometers with the vibrating string, the resonant frequency is sensitive to string tension and density of the fluid that surrounds it. This sensitivity to density often increases by fixing the string at the upper end and the fixing of the mass at the lower end, thereby using the principle of Archimedes. However, if the density is determined from al the alternative source, for example, from the equation of state, only the width of the resonance line must be stable.

In General viscometer with a vibrating string, for example viscometer-densimeter 60, is the ultimate device for which, theoretically, is not required to determine the calibration constants. In practice, however, some physical properties of the strings 74, such as density and radius cannot be determined with sufficient accuracy by an independent ways, therefore, these properties are usually determined by calibration. To do this, carry out measurements both in vacuum and in the fluid, which is known viscosity and density. The first gives Δ0. Only the radius R of the strings is another unknown variable that is required to perform viscosity measurements. Knowing the viscosity and density of the calibration fluid, the radius of the strings can be defined in one dimension.

1. Modification of the working equations

The complex voltage V developed on the string 74, consist of V1caused by an electrical impedance strings 74, and V2resulting from the movement of the strings 74 in the presence of a magnetic field (equation 1). In addition to the contribution of the electrical impedance using the V1also take into account background noise, such as electrical crosstalk or other types of communication. Such interference give ascending is the growth of a relatively smooth background within the frequency range near the resonance frequency of the vibrating string 74. To adequately reproduce the measured complex voltage depending on frequency, in equation (2) includes additional frequency-dependent parameter, that is,

Without regard to the additional frequency-dependent term in equation (10) the measured complex amplitude is often not fully consistent with the working equations and, therefore, are responsible for significant error of the density and viscosity of the fluid. This is especially true for fluids with high viscosity.

2. Determination of density and viscosity of fluids on a vibrating string

To determine the density and viscosity of fluids is required, consistent with the working equations of the vibrating string 74. The method of approximation by the least squares method is based on the fact that the optimal description of the characteristics of the data array is the one that minimizes the sum of the squared deviation of the data from the fitted model (or working equations). The sum of squares of deviations is closely related to statistics agreement, called statistics Chi-square (or χ2)

where fi- rate; D(fi) and V(fi) is the complex voltage, registered and working equations, respectively; ν is the number of degrees of freedom in the selection of N data points.

The criterion of the least squares method is formulated as finding unknown parameters, including the density and viscosity of the fluid, with minimization measures Chi-square, defined in (11), that is,

,

where ρ, η, f0, Λ, a, b, c, and d are unknown parameters.

The Levenberg-Marquardt's algorithm [14] provides a nonlinear regression procedure to resolve this problem of minimizing.

Of all the unknown parameters in the amplitude (i.e. Λ) oscillations and constant related to the electric impedance of the fixed strings and other background noise (i.e. a, b, c and d), also determined by the minimization procedure. However, the fundamental uncertainty between the density, viscosity and f0prevents approximation as such in the selection of the true values of density and viscosity. To eliminate this fundamental uncertainty, additional correlations between density, viscosity, and f0use as bounding conditions in the approximation procedure. Mathematically, the relationship between these variables can be written in the General functional form as

Alternatively, the ratio may also include the results of additional measurements, such as the half-width (g) the reason the sa and the resonant frequency (f r), which can be obtained from the data

Equation (13), (14) can be tested experimentally using calibration procedures or empirically on the basis of field data. In this application the preferred implementation is a special case of equations (13), (14), i.e. the case of hyperplanes, given a fixed f0. As shown in the publication Retsina and others (Retsina, T., Richardson S.M., Wakeham W.A., Applied Scientific Research, 1987, 43, 325-346; and Retsina, T., Richardson S.M., Wakeham W.A., 1986, 43, 127-158), f0can be defined as the resonant frequency of the string 74 in vacuum, which is directly related to the tension acting on the string 74. If f0known or specified, can be limited to the minimum search on the hyperplanes defined fixed f0.

On figa shows a block diagram 134 sequence method for the simultaneous calculation of the viscosity and density described above. First, in step 134d calculations introduce constants for the diameter of the strings, the density of the string and the index of internal friction; the initial estimate for the density and viscosity of the fluid and the resonance frequency f0and constraints G (density, viscosity and the resonance frequency f0). Then in step 134d calculate initial response strings. The initial response strings can is set in the form of in-phase and quadrature voltages.

Next, in step a receive input data, such as in-phase and quadrature voltage depending on the frequency, and then calculates at step 134f the Chi-square based on the difference between the data and the computed response. Update estimates of density, viscosity of the fluid and then get the resonant frequency, lambda, a, b, c and d. As shown in step 134g, to receive updates can be used by any non-linear regression analysis. Next, the calculation circuit 68 is the test for convergence (step 134h), based on criteria Chi-square, and updated estimates. If you check on the convergence proves convergence to a specified or appropriate degree, the process proceeds to step 134i, which displays the density and viscosity of the fluid. However, if the test for convergence indicates convergence outside a specified extent, the process goes back to step 134d, where the response string is recomputed based on the updated density, viscosity of the fluid and the resonant frequency. Steps 134d, 134e, 134f, 134g and 134h repeat until, while checking convergence will not indicate convergence within a given class.

On fig.7b shows a block diagram 136 sequence for simultaneous calculation of viscosity and density in exactly the same way as described above with reference to figa, with the following exceptions.

In the calculation of the viscosity and density (fig.7b) sensitive block 62 test to determine the resonant frequency f0. To sized the sensing unit 62, it is placed in the artificial climate chamber with a known fluid, and then the temperature and pressure change, in order to obtain calibration data. Next, the calibration data is injected (step 136b) in the calculation circuit 68, and these calibration data are used (step 136) to calculate the resonant frequency f0.

On Fig is a diagram illustrating the surface characteristics of the Chi-square crossed by a fixed hyperplane f0where there is a global minimum. Chart has axes F, D and V. the Axis F represents the frequency f0in Hertz. Axis D represents the density of the fluid surrounding the string 74, in kg/m3. Axis V represents the viscosity of the fluid surrounding the string 74, SP. The meaning of the shading is the representation of the values distributed according to the law Chi-square, with darker colors indicate lower values, distributed by law Chi-square. The location of the minimum 137 provides estimates of the density and viscosity.

If f0stable and known with an accuracy of ±1 Hz, for a broad class of fluid density of the fluid can be determined with an accuracy of 3-4%. For high-viscosity fluids error will lower the (1-2%). If f0known with a precision of ±0.5 Hz, the error for the density is reduced to about 1-2% for a wide class of fluids. The uncertainty of the viscosity is typically lower than the margin of error for the density (about 3%), if f0known with an accuracy of ±1 Hz. Similarly, the uncertainty of the viscosity is generally lower for high-viscosity fluids. For the simultaneous measurement of density and viscosity of the fluid in the preferred embodiment, requires sensitive block, forming a variable frequency oscillator that is designed to obtain a stable and predictable f0in a wide range of temperatures and pressures. The typical ranges of temperature and pressure downhole conditions are in the range from 50 to 200°C and from 2.07 to 172,4 MPa (300 to 25000 lb/in2).

Figure 9 shows the sensing unit 150 according to other variant embodiments of the invention, intended for use in the viscometer-densimeter 60. As will be discussed in more detail below, the sensing unit 150 is similar in construction and operation of the sensing unit 62 described above, except that the sensing unit 150 is equipped with a pair of conductive connectors 152, separated by insulating the outlet tube 154 surrounding the string 156, instead of the conductive first body element 90 and the second body element 92, separated by the outstretched parallel to the layer 96. The sensing unit 150 will be described in more detail below.

The sensing unit 150 forms a frequency oscillator that is designed to obtain a stable and predictable frequency f0to at least two different parameter, such as density and viscosity of the fluid, in which the sensing unit 150 shipped, could be computed simultaneously by the data generated by the sensor unit 150.

For clarity, figure 9 connectors 152 indicated by the position 152a and 152b. Connectors 152 are identical in construction and operation. Therefore, the following paragraphs will describe only the connector 152a. Connector 152a provided with a clamping element 158, the presser plate 160 and at least one fastener 162, intended for connection to the pressure plate 160 to push the element 158. The clamping element 158 is attached to the outlet tube 154 through any suitable conjugated node. For example, the clamping element 158 equipped with terminal support 166, which is associated with a specific area of the outlet tube 154 so that the end bearing 166 is supported by the outlet tube 154. Delivery tube 154 provided with a narrowed section 168 and end bearing 166 forms a clamp that is located on top of the narrowed section 168. In addition, the clamping element 158 has a flange 170 that is attached to the end supports 166 and stretched from her. The flange 170 is provided what about the at least one locking pin 174 to center the strings on the flange 156 170. Preferably, the clamping element 158 has been provided with at least two spaced apart a distance locking pins 174 to string 156 could be threaded between the locking pins 174.

Fasteners 162 attach the presser plate 160 to push the element 158 to clamp the string 156. Fastener 162 may be any type of device capable of connecting the clamping element 158 with anti-squeak plate 160. For example, fastener 162 may be a screw.

Preferably, the delivery tube 154 is made of a material that has the same thermal expansion coefficient as the string 156. When the string 156 are made of tungsten, delivery tube 154 may be made of ceramics, such as processed on the machine ceramics based on silicon nitride (Shapal-M).

At least one hole 180 formed in the locking element 158 for inflow or outflow of fluid in the outlet tube 154 and out through the opening 180. The clamping element 158 may be provided with at least two holes 180, with each hole 180 is polukrugom form. However, it should be clear that the shape of the holes 180 may vary depending on the desires of the developer. More precisely, it should be clear that the holes 180 can be any asymmetric, symmetric, or fanciful form.

trono 156 is made similarly to the string 74, considered above. String 156 is supported and tensioned within the outlet tube 154 in the same manner as string 74 is supported and tensioned within the housing 76. The signal paths 75A and 75b from processor 66 signals and calculation circuit 68 is attached to the appropriate connectors 152 by any suitable means, such as screws, bolts, clamps, etc.

As discussed above, if f0resonance in vacuum from equation (1) of the sensing unit 150 is stable, it is possible to determine both the density and the viscosity measured complex voltages depending on the resonance frequency. The sensing unit 150 includes two metal connector 152 separated outlet tube 154 formed of insulating material. These materials have different elasticity, and in some cases also and thermal properties. Preferably, the connectors 152 and delivery tube 154 are held together only by the string tension 156.

Preferably, the sensing unit 150 had f0independent of fluid properties and pressure. The dependence on pressure can make a small, but still identifiable contribution to the compressibility of the material of the strings. In addition, the response strings 156 to temperature changes, which includes differential thermal expansion, arose the abuser due to the use of dissimilar materials in the construction of the resonator, must be measurable or ischislenii. String 156 is stretched and forced to move in the transverse direction by passing through it an electric current in the presence of a perpendicular magnetic field. These points suggest that the sensing unit 150 may be improved by eliminating rotational movement of the string 156, which may occur due to the elliptical cross-section strings 156, and in addition, each end of the string 156 in the sensing unit 150 must be electrically isolated to allow flow through it of an electric current.

Despite the roughness of the surface, the tungsten is the preferred material for the strings 156, designed for measurements of properties, including liquid, because the module E is young's modulus (≈411 GPA)and density ρs(≈19300 kg·m-3) are high compared with other materials. When the string 156 pull, the first indicator of the above helps to ensure a stable resonance, whereas the density provides sensitivity to the fluid around it due to the ratio ρ/ρsin equations (4) and (5). The influence of surface roughness is negligible provided that the amplitude of vibration is small, and the Reynolds number less than 100. For measuring the density of W is lateline, to the density of the string sought to the density of the fluid, it is theoretically derived from the concept of added masses. So it can be used tungsten, but depending on the expected density of the fluid being measured, other materials with lower density are also acceptable.

While minimizing the effects of differential thermal expansion of such a choice of material of the string determines the material used for connectors 152, outlet tube 154 and tensioning mechanism. It is desirable that the mechanical properties of the dielectric material from which is formed breather pipe 154, were as close as possible to the mechanical properties of the materials used for strings 156 and connectors 152. For example, the effect of differential thermal expansion on the string tension when the temperature deviates from the ambient temperature, can be reduced by selecting a material with a linear thermal expansion coefficient equivalent to the coefficient of linear thermal expansion of tungsten. Shapal-M, which is processed on the machine ceramics with high thermal conductivity, compressive strength of 1 GPA, has a coefficient of linear thermal expansion α=(1/L)dL/dT=5.2 x 10-6K-1at T=298 K, while α (W, 298 K)≈4,5·10-6K-1. Alternate the main materials, intended for use as insulating material may include aluminum nitride or Makor, however, α for these materials is not equivalent to α for W.

To reduce changes to f0due to temperature , pressure and fluid properties, the criteria described in the preceding paragraph, were used for the formation of another embodiment of the sensor unit 200 to the viscometer-densimeter 60 with a vibrating string (11 and 12). The sensing unit 200 is similar in construction and operation of the sensing unit 150, except that the effect of temperature and pressure is reduced due to the production of the sensing unit 200 mainly from the same material, such as tungsten, with the same thermal expansion and elastic properties, it also minimized the rotation of the string 156 to reduce the influence of variations of fluid properties on f0. The sensing unit 200 (11) consists of two connectors 204 and 306, both formed from tungsten and an outlet tube 208 is located between the connectors 204 and 206 within which is held the string 202. String 202 are rigidly connected to each connector 204 and 206. In the example shown at 11 and 12, the string 202 is welded to electronic welding to each connector 204 and 206.

The connector 204 includes a sleeve 212 and end on the hoist 214. The sleeve 212 is attached to the string 202 and is designed to prevent rotation of the string 202. For example, to prevent rotation of the string 202 sleeve 212 may have a noncircular cross section, for example square. The sleeve 212 is located within a cavity formed in the end part 214. To facilitate alignment with the connector 206 of the sleeve 212 is shaped. The sleeve 212 may be of any shape suitable to facilitate alignment of the connector 206. For example, to facilitate alignment with the connector 206 of the sleeve 212 may have a tapering or conical end. String 202 may be attached to the sleeve 212 using any suitable means which rigidly attaches the string 202 to the sleeve 212. For example, the string 202 may be located inside the slit (not shown)formed in the sleeve 212, and, as described above, are welded by an electron beam, so that the sleeve 212 forms a collar around the strings 202.

The connector 206 is supplied with the end Assembly support 216, sleeve 218, insulator 220 and adjusting the node 222 to regulate the relative position of the sleeve 218 and the end Assembly support 216. The sleeve 218 is attached to the string 202 as well as the sleeve 212 is attached in the string 202. The sleeve 218 is designed to prevent rotation of the string. For example, to prevent rotation of the string 202 sleeve 218 may have a noncircular cross with the increase, for example square. The sleeve 218 is located within the cavity 224 formed in the end part 216.

The insulator 220 provides electrical isolation between the end piece 216 and sleeve 218. In the embodiment shown in 11 and 12, the insulator 220 is formed in the form of a sleeve covering the cavity 224 inside end parts 216 and continuing on the outer surface 226 of the end parts 216. The insulator 220 can be formed from any insulating material that can withstand downhole conditions. For example, the insulator 220 can be made of a ceramic material, such as machined on the machine tool ceramics based on aluminum nitride (Shapal-M).

The adjusting unit 22 can be any device capable of adjusting the relative position of the sleeve 212 and the end part 216 to enable the tension of the string 202. For example, a regulating unit 222 may include a nut 230 string tension, which screw on the sleeve 212. Of course, many other famous designs, which can be used to hold down the strings 202 to the housing to enable the tension of the string 202. For example, between two clamps or connectors, as shown, or with the use of springs.

As stated above, it is desirable that stretched vibrating string 74, 156 or 202 had Stabi is inuu resonant frequency with respect to temperature, pressure and fluid. Stable resonant frequency significantly weakens the condition of a constant string tension. Although it is acceptable to construct a stable oscillator on the basis of mechanical considerations, another solution is provided by the concept of relative measurements. On Fig presents the downhole tool 10A according to other variant embodiments of the invention, which is similar in design and operation of the downhole tool 10 described above, except that the downhole tool 10A has two or more viscometers-densitometer 60, one of viscometers-densitometer 60 (60A) is located in the fluid with unknown viscosity and density, and the other one of the viscometers-densitometer 60 (60b) is in fluid of known viscosity and density. Each of viscometers-densitometer 60A and 60b provided with magnets 64a, 64b. This solution uses two such sensitive unit 250a and 250b, while one is immersed in the fluid with unknown properties of density and viscosity, and the other in a fluid of known properties. Sensitive units 250a and 250b can be constructed by the method described above for sensitive blocks 62, 150 or 200 described above.

The sensing unit 250a is estimated inside the drain line 252, which can be estimated diversion of the Oh line 46, cleaning the drain line 46a or selected by the camera 50, discussed above. In the downhole tool 10A is provided of a bent pipe or elbow 254, which is communicated to the fluid outlet line 252. Knee 254 forms a chamber 255 comparisons, which are known to the fluid and the sensing unit 250b. The downhole tool 10A is equipped with a node 256 pressure equalization designed to equalize the pressure inside the evaluation drain line 252. Generally speaking, a node 256 pressure equalization can be any device that is able to equalize the pressure between the estimates of the drain line 252 and Luggage 255 comparison. For example, the node 256 (Fig) pressure equalization may include a piston 258 having a reciprocating motion, which pressure equalization is moved relative to the camera 255 comparison.

As indicated above, the sensing units 250a and 250b is connected to the one or more processors 260 signals and for calculating the circuit 262 for receiving the excitation voltage and determining one or more parameters of the fluid such as viscosity and density. The processor 260 signals and calculation circuit 262 is similar in construction and operation to the CPU 66 signals and settlement scheme 68 discussed above.

The ratio of the resonances are sensitive units 250a and 250b determined as shown for example, on figa and 14b. On figa shows the process 170 for calculating the density and viscosity of the fluid by using two viscometers-densitometer 60A and 60b shown in Fig. The process 170 has steps similar to the steps on figa. For clarity, the same steps are denoted by the same positions 134a, 134b, 134d, 134e, 134f, 134g, 134h and 134i and will not be described in detail again.

In General, the density and viscosity of the fluid in the chamber 255 comparison determine the steps 172 and 174 by known methods, for example, using tables of the U.S. national Institute for standards and technology (NIST). As shown in step 176, the calculation circuit 262 receives signals from the sensor unit 250b and then at step 178 calculates the resonant frequency on the basis of known density and viscosity of the fluid inside the chamber 255 comparison. After that calculation circuit 262 calculates the viscosity and density of the method described above for figa.

On FIGU presents another way 180 calculate the density and viscosity of the unknown fluid inside the bypass line 252. In method 180 initial measurement of viscosity, density fluid and a lambda, a, b, c and d introduce the steps 182 and 183 of calculation circuit 262. In the calculation circuit 262 enter step 184 constant, for example the diameter of a string, the density of the string and the index of internal damping. Then in the analytical model 262 impose other inputs (SAG), for example temperature and pressure, subjected to the sensing unit 250a in the drain line 252. Then with sensitive units 250a and 250b read steps 188 and 190 of the input data, such as in-phase and quadrature data at step 183 calculates complex data handling with sensitive units 250a and 250b. After that, in step 192 of the design scheme 262 display the values of density and viscosity of the fluid surrounding the sensor unit 250a.

Although the above described two previously mentioned method to calculate the viscosity and density, it should be clear that can be used any way, for example a measurement of the ratio of the output signals generated by the sensor units 250a and 250b.

Assuming that the strings are inside the sensitive units 250a and 250b similar design (preferably of identical construction and are exposed to the same temperature and the same pressure, thus providing constant instability due to these variables, and obtained evidence of a stable oscillator. If both concepts are combined, that is, the comparison or measurement of attitudes and stable geometry described above in relation to sensitive blocks 150 and 200, the resonator is stable and will be able to provide as density and is Ascoli.

From the preceding description it should be clear that various modifications and changes may be made in the preferred and alternative embodiments of implementation of the present invention without deviation from its true nature. To perform a desired operation of the device included in the present application, can be actuated manually and/or automatically. Actuation can be carried out on request and/or based on data detected conditions and/or analysis of the results of downhole operations.

This description is intended for illustration only and should not be construed in a restrictive sense.

1. Viscometer-densimeter for a downhole tool positionable in a wellbore through a subterranean formation, while the downhole tool is designed to transfer at least part of the fluid from the reservoir into the viscometer-densimeter containing
the sensing unit is placed inside the well
tool and containing at least two spaced connector
string suspended from the tension between these at least two connectors so that the interaction with the fluid strings when viscometer-densimeter is located within the downhole tool and the downhole tool located the Yong in the underground reservoir and receives fluid from an underground reservoir, the design of the connectors and the strings ensures the formation frequency of the oscillator, and the connectors and string made from materials having similar coefficients of thermal expansion,
design scheme, receiving a response from the strings, to calculate at least two parameters of the fluid interacting with the string,
at least one magnet that creates a magnetic field that interacts with the string,
means for preventing rotation of the string with respect to the connectors, made in the form of a sleeve having a non-circular cross-section.

2. Viscometer-densimeter according to claim 1, characterized in that the connectors and the string is made from a material of the same type.

3. Viscometer-densimeter according to claim 1, characterized in that these two parameters are the viscosity and density.

4. Viscometer-densimeter according to claim 1, characterized in that it further comprises a tube for flow in which the string is suspended by means of these connectors, and tubing, connectors, and string made from materials having similar coefficients of thermal expansion, for the formation frequency of the oscillator.

5. Machine-readable medium containing a logical unit for receiving a response from at least two sensor units, with one feeling twicely block is located in the fluid with unknown parameters, and other sensitive unit is in fluid with known parameters, and to calculate a signal indicating at least two unknown parameter of the fluid, which is one of the sensitive block, when, essentially, the exception of variations in the conditions of the wellbore surrounding the sensing unit in fluid with unknown parameters, while the logical device to calculate the signal contains the logic to perform a comprehensive treatment of the data received from the sensitive blocks.

6. Machine-readable medium according to claim 5, characterized in that two unknown parameter are viscosity and density.

7. The downhole tool is placed in a well bore having a wall and passing through a subterranean formation with a fluid containing
a housing surrounding at least one of the evaluation cavity
device for conveying fluid passing from the housing and interacting with the formation of a seal with the wall of the borehole and having at least one inlet opening that communicates with the evaluation cavity for receiving fluid from the reservoir and placing in the evaluation cavity
viscometer-densimeter containing
the sensing unit is placed inside the downhole tool containing
at least two spaced connector
trono, suspended under tension between the said at least two connectors so that the interaction with the fluid strings when viscometer-densimeter is located within the downhole tool and the downhole tool is located in the underground reservoir and receives fluid from an underground reservoir, and the design of the connectors and the strings ensures the formation frequency of the oscillator, and the connectors and string made from materials having similar coefficients of thermal expansion,
design scheme, receiving a response from the strings, to calculate at least two parameters of the fluid interacting with the string,
at least one magnet that creates a magnetic field that interacts with the string,
means for preventing rotation of the string with respect to the connectors, made in the form of a sleeve having a non-circular cross-section.

8. The downhole tool according to claim 7, characterized in that the connectors and the string is made from a material of the same type.

9. The downhole tool according to claim 7, characterized in that the two parameters are the viscosity and density.

10. The downhole tool according to claim 7, characterized in that it further comprises a tube for flow in which the string is suspended by means of connectors, with the delivery tube, the connector is a string made from materials having similar coefficients of thermal expansion, for the formation frequency of the oscillator.

11. The downhole tool according to claim 7, characterized in that it further comprises a camera comparison, containing a fluid of known properties, downhole conditions inside the chamber compare similar downhole conditions inside of the evaluation chamber, the sensing unit inside the camera comparison, one sensitive block located in the fluid with unknown parameters estimated cavity, and other sensitive block located in the fluid with known parameters in the camera comparison.

12. A method of measuring at least two unknown parameters of the unknown fluid in the wellbore passing through the reservoir with fluid, namely, that
place the device for receiving fluid downhole tool, providing interaction with the wall of the well bore with seal
extract the fluid from the reservoir and direct in the evaluation cavity within the downhole tool,
perform the data selection of the fluid within the evaluation cavity through viscometer-densimeter with
the sensing unit is placed inside the downhole tool containing
at least two spaced connector
string suspended from the tension between these, at m is re, the two connectors so that the interaction with the fluid strings when viscometer-densimeter is located within the downhole tool and the downhole tool is located in the underground reservoir and receives fluid from an underground reservoir, and the design of the connectors and the strings ensures the formation frequency of the oscillator, and the connectors and string made from materials having similar coefficients of thermal expansion,
design scheme, receiving a response from the strings, to calculate at least two parameters of the fluid interacting with the string,
at least one magnet that creates a magnetic field that interacts with the string,
means for preventing rotation of the string with respect to the connectors, made in the form of a sleeve having a non-circular cross-section.

13. The method according to item 12, wherein the estimated cavity using the discharge line.

14. The method according to item 12, wherein the estimated cavity using selected camera.

15. The method according to item 12, characterized in that it further calculates at least two parameters by using the data taken within the evaluation cavity.

16. The method according to item 12, wherein the at least two parameters include viscosity and density.

17 the Method according to item 12, characterized in that it further carry out the selection data against a known fluid inside the chamber comparison with the temperature and pressure associated with the temperature and pressure of the fluid within the evaluation cavity.

18. The method according to item 12, characterized in that it further calculates at least two parameters of the unknown fluid within the evaluation cavity by using data taken from camera comparison, and data selected from the evaluation cavity.



 

Same patents:

FIELD: measuring technology.

SUBSTANCE: built-in Coriolis measuring device contains a vibration-type measuring gauge with at least one straight measuring tube for flowing a measured (two- or multiphase) medium supplied from the attached pipeline, a torsion vibration exciter from the measuring tube, a sensor for delivering the measuring signal caused by vibrations of the measuring pipe. An electronic device of the measuring device electrically connected to the measuring gauge with at least one measuring signal and/or an exciting signal generates the mass expense/density and/or viscosity of the measured medium. Besides the electronic device, on the basis of at least one measuring and/or exciting signal periodically evaluates frequency of torsion vibrations of the measuring tube and taking this frequency as a basis, controls the working condition of the measuring tube wall (thickness, weight of the formed deposition, or abrasion), as well as a site of the attached pipeline.

EFFECT: invention improves measurement accuracy.

30 cl, 7 dwg

FIELD: physics, measurements.

SUBSTANCE: method for non-contact photometric measurement of metal melts viscosity based on attenuation of torsional oscillations. At first periodic reversible twisting of elastic thread is carried out with crucible suspended on it with metal melt. Reversible twisting of elastic thread is performed by means of control with the help of computer by commutation of electromagnet unit. Besides crucible is connected with elastic thread with the help of ceramic rod. At upper end of ceramic rod, magnetic element is rigidly fixed, being arranged in the form of disk, rod or cylinder. Source of electromagnet field together with magnetic element are composite parts of electromagnet unit. Mass of magnetic element is less or equal to mass of crucible with metal melt placed in it. After disconnection of electromagnet unit, parametres of trajectory of light beam reflected from mirror fixed on ceramic rod are measured, afterwards amplitude-time parametres of sample crucible torsional oscillations attenuation are calculated.

EFFECT: reduced time of experiments, lower waste of melt components and increased accuracy of metal melts viscosity measurements results.

3 cl, 4 dwg

FIELD: physics.

SUBSTANCE: research method for structure transformation in liquids at which temperature changes take place in liquid sample under study; volume of sample is less then 1 cm3. In each cycle of monotonous and continuous cooling or heating measurements of dynamic shear viscosity versus time η(t) are made in liquid by low-frequency oscillatory viscometer. Measurements of liquid temperature change versus time T(t) are also made. Calculations of temperature process rate Θ(T) as rate-of-change of temperature versus time Θ(T) = ∂T/∂t. By measurement results dynamic shear viscosity versus temperature η(T, Θ) is measured. Based on this indicator thermal energy function E(T) and intermolecular energy ε(T) are calculated by formula , where C is constant of integration. Time duration τ of structure transformation processes in any temperature range from T1 up to T2, time period τ for any function E(T) or ε(T) required for temperature change of sample from T1 up to T2 are calculated by formula .

EFFECT: provision of authentic and reliable determination and quantitative description of time-resolved structure transformation in any homogenous and heterogenous liquids.

2 dwg

FIELD: physics.

SUBSTANCE: substance of invention consists in method for determination of properties of liquid filling layer in medium, as well as properties of medium and layer. Crack vibrations are registered. Wave characteristics of standing boundary waves that are distributed along crack surfaces are defined on the basis of registered vibrations with account of medium and liquid properties. Method is based on analysis of vibrations of areas filled with liquid on the basis of boundary waves that are distributed in their surfaces.

EFFECT: simplicity of data processing specific for it, efficient monitoring of liquid-filled areas, which may be performed on-line.

2 cl, 1 dwg

FIELD: physics.

SUBSTANCE: before trajectory parameters of mirrored light beam are recorded, synchronous detection is carried out with automatic amplitude control. Device presents synchronous detector and accommodates integrated photosensors. Light source is modulated. Besides, light source can be light-emitting diode cluster with pulses of optimal parameters.

EFFECT: reduced data loss, as well as higher measurement reliability and accuracy.

6 cl, 4 dwg

FIELD: physics.

SUBSTANCE: method involves excitation of continuous harmonic oscillation of vibratory converter inserted into the measured medium, measurement of medium temperature, as well as measurement of output signal of vibratory converter followed with calculation of density and viscosity. Output signal of vibratory converter is sampled for driving frequency period. Sample data are controlled thus resulting in automatic amplification control and rated sample data then used to calculate Fourier transform coefficients for the first signal harmonic. These coefficients are used to control noise level, search of resonance zone wherein resonant frequencies of preset phase shift is captured and kept. Related device for method implementation contains signalling processor 1, programmed frequency synthesiser 2, power amplifier 3, vibratory density converter 4, amplifier 5 of programmed amplification constant, temperature sensor 6, transceiver 7 and input-output 8.

EFFECT: higher accuracy and noise stability, extended application and enhancement.

5 cl, 1 dwg

FIELD: physics; engineering procedures.

SUBSTANCE: oscillatory viscometer contains mechanical vibrator with test body and three electromechanical converters. One of electromechanical converters is motion signal source and through rectifier is connected to one of inputs of comparator on other input of which reference voltage comes. The output of the comparator is connected with driving input of controlled amplifier main input of which is connected to limiting amplifier, and the output - to the second converting generator of mechanical force. The input of the limiting amplifier is connected to the converting motion signal source. To the second input of the comparator through the additional rectifier one more electromechanical converter mounted on vibrator and connected to the limiting amplifier is attached, on signal of which reference voltage is formed.

EFFECT: expansion of measurement possibilities due to elimination of motion amplitude dependent signal invariable component.

3 dwg

FIELD: invention is assigned for measuring mass consumption, density, viscosity and pressure of medium containing in reservoir or in flow along pipeline.

SUBSTANCE: device has sensor of vibration types and electronic block connected with sensor. Sensor arrangement of sensor has first and second sensor elements for giving measuring signals (S1, S2) and first and second temperature sensors for giving temperature measuring signal (θ12). Using measuring signal (S1) and meaning (K1) of correction for measuring signal (S1), electronic block works measuring meaning (X) presenting physical parameter. At that electronic block calculates meaning (K1) of correction with aid of temporary characteristic of temperature signal (θ1) taking into consideration meanings of temperature registered before that by temperature sensor. Invention provides good compensation in measuring signal of temperature mistake in unadjusted transitional field of distribution of temperature inside sensor at using of only small number of temperature sensors.

EFFECT: measures mass consumption, density, viscosity or pressure of medium.

23 cl, 8 dwg

Viscosity meter // 2315974

FIELD: devices for measuring viscosity of fluid passing in pipeline, namely in explosion hazard zones.

SUBSTANCE: viscosity meter includes vibration type measuring pickup having at least one vibrating at operation measuring tube for passing fluid. In order to provide vibration of measuring tube excitement system through which exciting electric current is passed is used. In order to provide exciting electric current and in order to take measured viscosity value being instantaneous viscosity of fluid meter is provided with electronic circuit connected to double-wire circuit for controlling process which is connected with DC source. Electronic circuit supplies viscosity signal to said double-wire circuit for controlling process. In variant of invention electronic circuit modulates measured viscosity value with use of amplitude of direct current passing in said double-wire circuit. Invention provides possibility for working in electric current range less than 4 mA.

EFFECT: possibility for using standard interface.

28 cl, 11 dwg

FIELD: measuring technique.

SUBSTANCE: method comprises preliminary measuring of frequency and attenuation coefficient of the vibration system without the specimen, filling the specimen into the thin-walled cell, measuring the values of frequency and attenuation coefficient of the system in the presence of the specimen, determining viscosity and shear modulus of the specimen by comparing the system vibration in the presence and in the absence of the specimen. The device comprises torsion pendulum made of inertia disk, flexible member, and specimen. The fluid specimen is set into the thin-walled cell. The first end of the cell is secured to the inertia disk, and the second end is connected to the unmovable base. The flexible member is made of a rubber cord that is perpendicular to the axis of vibration. The mid point of the cord is connected with the disk at the maximum distance form the axis.

EFFECT: expanded functional capabilities.

2 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: sounding electrode assembly execute fluid medium sampling from a borehole, going through underground reservoir with a fluid medium, located beyond a contaminated fluid medium layer, surrounding the borehole. The sounding electrode assembly contains a case, executed with ability to move forward from down hole equipment and a located in the case parker, with a distal surface for the full contact with the borehole section. The parker has internal and external peripheries, at that the external one limited with a channel, going through the parker. The parker additionally equipped with a channel (channels) executed in the distal surface and located with ability to limit a ring cleaning intake nozzle between the internal and the external peripheries. A bypass channel goes through the parker for natural fluid medium bypassing and/or the contaminated fluid medium between channels. In the parkers channel a sampling tube installed densely for the natural fluid medium bypassing to the second intake hole of the case and to equipment.

EFFECT: providing of required compacting with the reservoir, increase of clean fluid medium flow into the equipment, fluid medium flow into the instrument optimisation.

26 cl, 42 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to underground formation analysis. Proposed device comprises instrument casing that can move inside wellbore extending into underground formation, probe housing carried by instrument casing and designed to isolate wellbore wall zone, actuating mechanism to move said probe unit between preset position whereat instrument casing moves and developed position intended for wellbore wall isolation. It comprises also perforator that passes through said probe unit to sink wellbore wall isolated zone section and pass through at least one of strengthened formations or casing strings, power source arranged in instrument casing and connected with perforator to control it. It uses also bypass line passing through instrument casing section and connected with at least one of the elements that follow, i.e. perforator, actuating mechanism, probe unit, and combination thereof to suck in brine fluid. It is connected also with pump arranged in instrument tool to suck in brine fluid into instrument casing through aforesaid bypass line.

EFFECT: higher accuracy.

18 cl, 24 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to device and method allowing the bench estimation in drilling. The proposed device arranged in wellbore, nearby the subsurface bench, comprises the casing, casing fluid inlet, fluid pump communicating with the said casing fluid inlet and incorporating the first piston fitted in the pumping chamber to suck in and discharge fluid when acted upon by tubing pressure.

EFFECT: device and method higher reliability and efficiency, space saving in river drill pipes.

18 cl, 10 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention refers to downhole analysis of underground bed. Specifically invention refers to sampling through perforations in well bore leading to the underground bed. Method and device for caving reduction in perforation formed in well bore and leading from well bore to underground bed are offered. The well bore contains the device body with the lever moving forward. The perforation contains one or more caving block units mounted by using the lever. Caving block unit is designed so that to prevent caving from base fluid to the body through perforation.

EFFECT: reduced contamination of base fluid.

31 cl, 20 dwg

FIELD: mining engineering, oil industry.

SUBSTANCE: invention refers to oil and gas industry, specifically to formations testers. Tester comprises of elongated case, support blade moving forward from case surface and carrying probe to make canal between case inner surface and formation, sealing washer attached to probe, anchor mechanism for case mounting. Case includes eccentric area. Support blade is installed in such a way that it is possible to keep specified clearance between case and well bore side as case is installed on level in well bore. As formation pressure-testing operation is performed case is lowered into well bore up to level of measurements, support blade and anchor mechanism are moving forward, sealing washer and probe are pressed down, and formation pressure is measured. Risk of device blocking is reduced.

EFFECT: production of formation testers ensuring process optimization and reliability improvement.

18 cl, 2 dwg

FIELD: testing the nature of borehole walls, formation testing, methods or apparatus for obtaining samples of soil or well fluids, namely downhole tools to determine reservoir parameters.

SUBSTANCE: method involves arranging downhole tool having probe in well bore, wherein the probe comprises at least one executive mechanism for probe extension and retraction; moving the probe to provide probe contact with well wall and accumulating reservoir data. Protective screen is arranged around probe. The protective member may slide between retracted position, where protective member is arranged near body, and extended position, where protective member touches well bore wall, independently of probe.

EFFECT: improved probe and well bore protection, possibility to accumulate data or take samples without erosion.

30 cl, 10 dwg

FIELD: survey of boreholes or wells, particularly measuring temperature or pressure.

SUBSTANCE: device comprises pretest piston to be arranged in flow communication with reservoir, a number of manometers installed in pressure line and valves for selectively supply one of fluid or drilling mud in measuring device. Method involves performing the first test to determine reservoir parameter to be estimated; using the first pretest for the second pretest calculation and obtaining estimated reservoir parameters for reservoir characteristics evaluation.

EFFECT: possibility of reservoir testing device usage to perform measurements at well bottom during predetermined period, decreased land-based system intervention.

36 cl, 27 dwg

FIELD: testing the nature of borehole walls and formation testing particularly for obtaining fluid samples or testing fluids, in boreholes or wells.

SUBSTANCE: device comprises tubular body to be secured inside drilling string arranged in well bore. The tubular body is provided with one or several extensions created along body axis and forming expanded axial part. Probe is arranged in expanded axial body part zone having minimal cross-section. The probe may be moved between extended and retracted positions. In extended position probe may touch well wall to gather information from formation. To protect probe during drilling operation probe in brought into retracted position. Drive adapted to move the probe between extended and retracted positions is installed on the body.

EFFECT: increased accuracy of well and formation testing.

38 cl, 29 dwg

The invention relates to drilling wells and can be used to determine the various parameters and properties of the surface layer

FIELD: testing the nature of borehole walls and formation testing particularly for obtaining fluid samples or testing fluids, in boreholes or wells.

SUBSTANCE: device comprises tubular body to be secured inside drilling string arranged in well bore. The tubular body is provided with one or several extensions created along body axis and forming expanded axial part. Probe is arranged in expanded axial body part zone having minimal cross-section. The probe may be moved between extended and retracted positions. In extended position probe may touch well wall to gather information from formation. To protect probe during drilling operation probe in brought into retracted position. Drive adapted to move the probe between extended and retracted positions is installed on the body.

EFFECT: increased accuracy of well and formation testing.

38 cl, 29 dwg

FIELD: survey of boreholes or wells, particularly measuring temperature or pressure.

SUBSTANCE: device comprises pretest piston to be arranged in flow communication with reservoir, a number of manometers installed in pressure line and valves for selectively supply one of fluid or drilling mud in measuring device. Method involves performing the first test to determine reservoir parameter to be estimated; using the first pretest for the second pretest calculation and obtaining estimated reservoir parameters for reservoir characteristics evaluation.

EFFECT: possibility of reservoir testing device usage to perform measurements at well bottom during predetermined period, decreased land-based system intervention.

36 cl, 27 dwg

Up!