Dual-mode formation pressure testing device and method of formation tester

Abstract

The invention provides a dual-mode formation pressure testing device and method for a formation tester, and the device comprises a hydraulic drive pre-testing module, an electric drive pre-testing module and a control system, and the hydraulic drive pre-testing module and the electric drive pre-testing module are electrically connected with the control system. The output end of the hydraulic drive pre-test module and the output end of the electric drive pre-test module are connected with the same fluid pipeline in a sealed mode, and a pressure meter is arranged in the fluid pipeline. Operation of the hydraulic drive pre-test module and the electric drive pre-test module can be controlled through the control system, and then different to-be-detected stratums can be detected in a targeted mode; large-volume common pressure measurement of high-permeability stratums and conventional-permeability stratums can be met, small-volume accurate pressure measurement of low-permeability stratums can also be met, and adaptability and universality of the stratum tester to the stratums with the complex permeability are improved.

Description

Technical Field

[0001] This invention belongs to the field of formation pressure measurement technology, specifically relating to a dual-mode formation pressure testing device and method for a formation tester. Background Technology

[0002] Formation pressure is entirely borne by the fluid itself. Before the oil and gas layer is drilled through, the formation pressure in various parts of the oil layer remains in a relatively balanced state. Once the oil and gas layer is drilled through and put into production, the balance of oil and gas layer pressure is disrupted. Under the pressure difference between the oil and gas layer pressure and the bottom hole pressure, the fluid in the oil and gas layer will flow into the wellbore and sometimes even gush to the surface. Therefore, the detection of bottom layer pressure is particularly important during the oil and gas extraction process.

[0003] When performing formation pressure testing, formation testers need to draw in formation fluid and monitor pressure changes. One common method is to use a hydraulic pump to drive a piston, creating a pressure difference to draw in the formation fluid. This method calculates the piston displacement using the hydraulic pump's displacement, resulting in a relatively fast draw speed. It is suitable for measuring high-permeability and conventional-permeability formations. However, this method is affected by the accuracy of the hydraulic system and hydraulic leakage issues, leading to lower measurement and control accuracy. Another method is to use a motor to directly drive a piston, creating a pressure difference to draw in the formation fluid. This method calculates the piston displacement using the motor's rotation speed, resulting in higher measurement and control accuracy. It is suitable for measuring low-permeability formations. However, this method requires a complex precision transmission system to convert the motor's rotational motion into the piston's linear motion, making it difficult to achieve high draw speeds. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a dual-mode formation pressure testing device and method for a formation tester, so as to solve the technical problem that the existing technology cannot switch the detection mode according to the actual formation pressure conditions.

[0005] This invention is achieved through the following technical solution:

[0006] A dual-mode formation pressure testing device for a formation tester includes a liquid-driven pre-test module, an electric-driven pre-test module, and a control system. The liquid-driven pre-test module and the electric-driven pre-test module are both electrically connected to the control system. The output terminals of the liquid-driven pre-test module and the electric-driven pre-test module are respectively sealed and connected to the same fluid pipeline. A pressure gauge is installed in the fluid pipeline.

[0007] Furthermore, the liquid-driven pre-test module includes a hydraulic cylinder and a metering pump located at the output end of the hydraulic cylinder. The output end of the metering pump is sequentially equipped with a check valve and a reversing valve. The reversing valve is connected to a piston cylinder, and a first piston is installed inside the piston cylinder. The output ends of the reversing valve are respectively connected to both sides of the driving end of the first piston, and the output end of the first piston is sealed and slides against the inner wall of the fluid pipeline.

[0008] Furthermore, the metering pump is driven by a first motor, and the first motor is equipped with a first motor monitor; the one-way valve is also connected to an overflow valve.

[0009] Furthermore, a switching valve is provided on the side of the directional valve output end that is connected to the first piston drive end near the output end.

[0010] Furthermore, the electric drive pre-test module includes a motor drive assembly and a lead screw and a second piston disposed at the output end of the motor drive assembly. The lead screw is threaded inside the second piston, and the free end of the second piston is sealed and slides against the inner wall of the fluid pipeline.

[0011] Furthermore, the motor drive assembly includes a second motor, a reducer, and a second motor monitor. The reducer is located at the output end of the second motor, and the second motor is equipped with a second motor monitor.

[0012] The feature is that, based on the dual-mode formation pressure testing device of the formation tester according to any one of the claims, the second motor monitor is capable of detecting at least a fraction of a revolution of the second motor.

[0013] Furthermore, the fluid pipeline and the second piston are provided with a rotation limiting mechanism.

[0014] Furthermore, the fluid pipeline includes a first pipeline, a second pipeline, and a third pipeline. The first pipeline is connected to the output end of the liquid drive pre-test module, the second pipeline is connected to the output end of the electric drive pre-test module, and the third pipeline is used to connect to the formation.

[0015] A dual-mode formation pressure testing method using a formation tester includes the following steps:

[0016] When testing the formation permeability of high-permeability formations and conventional-permeability formations, the control system only activates the liquid-driven pre-test module. The liquid-driven pre-test module draws formation fluid through the fluid pipeline. Based on the actual drawing volume and drawing speed of the liquid-driven pre-test module, as well as the pressure in the fluid pipeline collected by the pressure gauge, the formation permeability is obtained using the formation fluid calculation method.

[0017] When testing the formation permeability of low-permeability formations, the control system activates only the electric drive pre-test module. The electric drive pre-test module draws formation fluid through the fluid pipeline. Based on the actual drawing volume and speed of the electric drive pre-test module, as well as the pressure in the fluid pipeline collected by the pressure gauge, the formation permeability is obtained using the formation fluid calculation method.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] This invention provides a dual-mode formation pressure testing device for a formation tester, comprising a liquid-driven pre-test module, an electric-driven pre-test module, and a control system. Both the liquid-driven and electric-driven pre-test modules are electrically connected to the control system. The output terminals of the liquid-driven and electric-driven pre-test modules are respectively sealed and connected to the same fluid pipeline. A pressure gauge is installed within the fluid pipeline. This application, through the control system, can control the operation of the liquid-driven and electric-driven pre-test modules, thereby enabling targeted testing of different formations. It can meet the requirements of large-volume general pressure measurement for high-permeability and conventional permeability formations, as well as small-volume precise pressure measurement for low-permeability formations, improving the adaptability and versatility of the formation tester for complex permeability formations.

[0020] This invention provides a dual-mode formation pressure testing method for a formation tester, comprising the following steps: When testing the formation permeability of high-permeability and conventional-permeability formations, the control system activates only the liquid-driven pre-test module. This module draws formation fluid through a fluid pipeline. Based on the actual draw volume and velocity of the liquid-driven pre-test module, and the pressure within the fluid pipeline collected by the pressure gauge, the formation permeability is calculated using a formation fluid calculation method. When testing the formation permeability of low-permeability formations, the control system activates only the electric-driven pre-test module. This module draws formation fluid through a fluid pipeline. Based on the actual draw volume and velocity of the electric-driven pre-test module, and the pressure within the fluid pipeline collected by the pressure gauge, the formation permeability is calculated using a formation fluid calculation method. This method, through its control system, can switch the testing mode based on the properties of the formation under test, improving testing accuracy and convenience. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the dual-mode formation pressure testing device of the formation tester of the present invention.

[0022] In the diagram: 1. Hydraulic drive pre-test module; 2. Electric drive pre-test module; 3. Control system; 4. Fluid pipeline; 5. Pressure gauge; 7. Formation fluid; 10. Hydraulic cylinder; 11. Metering pump; 12. First motor; 13. First motor monitor; 14. Check valve; 15. Overflow valve; 16. Directional valve; 17. Piston cylinder; 18. First piston; 19. Switch valve; 20. Second motor monitor; 21. Second motor; 22. Reducer; 23. Lead screw; 24. Second piston; 40. First pipeline; 41. Second pipeline; 42. Third pipeline. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] This invention provides an embodiment of a dual-mode formation pressure testing device for a formation tester, such as... Figure 1 As shown, it includes a liquid-driven pre-test module 1, an electric-driven pre-test module 2, and a control system 3. The liquid-driven pre-test module 1 and the electric-driven pre-test module 2 are both electrically connected to the control system 3. The output terminals of the liquid-driven pre-test module 1 and the electric-driven pre-test module 2 are respectively sealed and connected to the same fluid pipeline 4. A pressure gauge 5 is installed in the fluid pipeline 4.

[0027] Preferably, in this embodiment, the liquid-driven pre-test module 1 includes a hydraulic cylinder 10 and a metering pump 11 disposed at the output end of the hydraulic cylinder 10. The output end of the metering pump 11 is sequentially provided with a one-way valve 14 and a reversing valve 16. The reversing valve 16 is connected to a piston cylinder 17. A first piston 18 is disposed inside the piston cylinder 17. The output end of the reversing valve 16 is respectively connected to both sides of the driving end of the first piston 18. The output end of the first piston 18 is sealed and slides against the inner wall of the fluid pipeline 4.

[0028] Furthermore, the metering pump 11 is driven by a first motor 12, and the first motor 12 is equipped with a first motor monitor 13; the one-way valve 14 is also connected to an overflow valve 15.

[0029] Furthermore, a switching valve 19 is provided on the side of the output end of the reversing valve 16 that is connected to the drive end of the first piston 18 near the output end.

[0030] It should be noted that in this embodiment, the cylinder 10 is used to supply hydraulic oil, and the metering pump 11 is used to provide a preset rated pressure and flow rate. The flow rate provided by the metering pump 11 is the same per revolution, which facilitates accurate calculation of the displacement. The first motor 12 is used to drive the metering pump 11. The first motor monitor 13 is used to monitor the number of revolutions of the first motor 12, with an accuracy of several fractions of a revolution. In this embodiment, the accuracy of the first motor monitor 13 can reach one-twelfth of a revolution. The one-way valve 14 is located at the output end of the metering pump 11 and is used to prevent liquid backflow. The overflow valve 15 is used to release the overflowing liquid when the pressure exceeds the rated value. The system collects data; the reversing valve 16 is used to switch the direction of the oil circuit and change the direction of movement of the first piston 18. There is a first piston 18 in the piston cylinder 17. The output end of the first piston 18 is located in the first pipeline 40 and is used to draw in or discharge the formation fluid 7; the switching valve 19 is used to allow or prevent the movement of the first piston 18. Specifically, when the hydraulic pre-test module 1 is working, the switching valve 19 needs to be in the open state so that the first piston 18 can move. When the electric pre-test module 2 is working, the switching valve 19 needs to be switched to the closed state to prevent the first piston 18 from moving due to pressure changes of the formation fluid 7.

[0031] Preferably, in this embodiment, the electric drive pre-test module 2 includes a motor drive assembly and a lead screw 23 and a second piston 24 disposed at the output end of the motor drive assembly. The lead screw 23 is threadedly sleeved inside the second piston 24, and the free end of the second piston 24 is sealed and slides against the inner wall of the fluid pipeline 4.

[0032] Furthermore, the motor drive assembly includes a second motor 21, a reducer 22, and a second motor monitor 20. The reducer 22 is disposed at the output end of the second motor 21, and the second motor 21 is provided with the second motor monitor 20.

[0033] Furthermore, the second motor monitor 20 is capable of detecting at least a fraction of a revolution of the second motor 21. Specifically, the second motor 21 reduces its output speed and increases its torque through the reducer 22. The second motor monitor 20 is used to monitor the number of revolutions of the second motor 21, with an accuracy of a fraction of a revolution. In this embodiment, the accuracy of the second motor monitor 20 is one thirty-sixth of a revolution.

[0034] Furthermore, the fluid pipeline 4 and the second piston 24 are provided with a rotation limiting mechanism. Specifically, the second pipe 41 and the second piston 24 have a rotation limiting mechanism, which is used to make the second pipe 41 and the second piston 24 rotate at the same angular velocity. Furthermore, the top of the second pipe 41 is swivelly sealed to other pipes, and the bottom side wall of the second piston 24 is provided with a limiting structure that engages with the outer wall of the second pipe 41. When the second piston 24 rotates, it will drive the second pipe 41 to rotate at the same angular velocity. Specifically, one end of the lead screw 23 is connected to the reducer 22, and the other end is connected to the threaded second piston 24. When the lead screw 23 rotates, it can drive the second piston 24 to perform linear reciprocating motion. The limiting structure prevents the second piston 24 and the second pipe 41 from rotating relative to each other. The second piston 24 is used to suck or discharge the formation fluid 7 in the second pipe 41.

[0035] Furthermore, the fluid pipeline 4 includes a first pipeline 40, a second pipeline 41, and a third pipeline 42. The first pipeline 40 is connected to the output end of the liquid drive pre-test module 1, the second pipeline 41 is connected to the output end of the electric drive pre-test module 2, and the third pipeline 42 is used to connect to the formation.

[0036] In this embodiment of the invention, the control system 3 is used to monitor data and issue commands. The control system 3 can receive data from the first motor 12, the first motor monitor 13, the second motor 20, the second motor monitor 21 and the pressure sensor 5, and can also send commands to the first motor 12, the second motor 20, the reversing valve 16 and the switching valve 19.

[0037] This invention provides a dual-mode formation pressure testing method for a formation tester, comprising the following steps:

[0038] First, it should be noted that in this embodiment, the pressure gauge 5 is used to measure the pressure of the formation fluid 7. When the first piston 18 or the second piston 24 moves and extracts the formation fluid 7, a pressure drop will occur. As the formation fluid 7 continues to infiltrate and replenish, the pressure value will recover to a certain extent. By analyzing the data of pressure drop and pressure recovery, the formation permeability can be calculated.

[0039] When testing the formation permeability of high-permeability formations and conventional-permeability formations, the control system 3 activates only the liquid-driven pre-test module 1. The liquid-driven pre-test module 1 draws formation fluid through the fluid pipeline 4. Based on the actual drawing volume and drawing speed of the liquid-driven pre-test module 1, as well as the pressure in the fluid pipeline 4 collected by the pressure gauge 5, the formation permeability is obtained using the formation fluid calculation method.

[0040] Specifically, assuming that within a time period t, the number of rotations of the first motor 12 is measured by the first motor monitor 13 as N1 rotations, the displacement per rotation of the metering pump 11 is known to be C, and the areas of the left and right ends of the first piston 18 are S1 and S2 respectively, it can be calculated that: the actual flow rate entering the piston cylinder 17 is equal to N1×C, the actual suction volume of the formation fluid 7 is N1×C×S2 / S1, and the suction speed is N1×C×S2 / S1 / t. Finally, combined with the data collected by the pressure gauge 5, the formation permeability is calculated using the formation fluid mobility calculation method.

[0041] When testing the formation permeability of low-permeability formations, the control system 3 activates only the electric drive pre-test module 2. The electric drive pre-test module 2 draws formation fluid through the fluid pipeline 4. Based on the actual drawing volume and drawing speed of the electric drive pre-test module 2, as well as the pressure in the fluid pipeline 4 collected by the pressure gauge 5, the formation permeability is obtained using the formation fluid calculation method.

[0042] Specifically, assuming that within a time period t, the number of rotations of the second motor 21 measured by the second motor monitor 20 is N2 rotations, the reduction ratio of the reducer 22 is D1, the reduction ratio of the lead screw 23 is D2, the pitch of the lead screw 23 is M, and the area of ​​the second piston 24 is S3, the actual suction volume of the formation fluid 7 can be calculated as N2×D1×D2×M×S3, and the suction speed is N2×D1×D2×M×S3 / t. Finally, combined with the data collected by the pressure gauge 5, the formation permeability is calculated using the method for calculating formation fluid permeability.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-mode formation pressure testing device for formation testing, characterized in that, It includes a liquid-driven pre-test module (1), an electric-driven pre-test module (2), and a control system (3). The liquid-driven pre-test module (1) and the electric-driven pre-test module (2) are electrically connected to the control system (3). The output ends of the liquid-driven pre-test module (1) and the electric-driven pre-test module (2) are respectively sealed and connected to the same fluid pipeline (4). A pressure gauge (5) is installed in the fluid pipeline (4).

2. The dual-mode formation pressure testing device for a formation tester according to claim 1, characterized in that, The liquid-driven pre-test module (1) includes a hydraulic cylinder (10) and a metering pump (11) located at the output end of the hydraulic cylinder (10). The output end of the metering pump (11) is sequentially provided with a check valve (14) and a reversing valve (16). The reversing valve (16) is connected to a piston cylinder (17). A first piston (18) is provided inside the piston cylinder (17). The output end of the reversing valve (16) is connected to both sides of the driving end of the first piston (18). The output end of the first piston (18) is sealed and slides against the inner wall of the fluid pipeline (4).

3. The dual-mode formation pressure testing device for a formation tester according to claim 2, characterized in that, The metering pump (11) is driven by a first motor (12), and the first motor (12) is equipped with a first motor monitor (13); the one-way valve (14) is also connected to an overflow valve (15).

4. The dual-mode formation pressure testing device for a formation tester according to claim 2, characterized in that, The output end of the reversing valve (16) is provided with a switching valve (19) on the side of the drive end of the first piston (18) near the output end.

5. The dual-mode formation pressure testing device for a formation tester according to claim 1, characterized in that, The electric drive pre-test module (2) includes a motor drive assembly and a lead screw (23) and a second piston (24) located at the output end of the motor drive assembly. The lead screw (23) is threaded inside the second piston (24), and the free end of the second piston (24) is sealed and slides against the inner wall of the fluid pipeline (4).

6. The dual-mode formation pressure testing device for a formation tester according to claim 5, characterized in that, The motor drive assembly includes a second motor (21), a reducer (22), and a second motor monitor (20). The reducer (22) is located at the output end of the second motor (21), and the second motor (21) is equipped with a second motor monitor (20).

7. The dual-mode formation pressure testing device for a formation tester according to claim 6, characterized in that, The second motor monitor (20) is capable of detecting at least a fraction of a revolution of the second motor (21).

8. The dual-mode formation pressure testing device for a formation tester according to claim 5, characterized in that, The fluid pipeline (4) and the second piston (24) are provided with a rotation limiting mechanism.

9. The dual-mode formation pressure testing device for a formation tester according to claim 1, characterized in that, The fluid pipeline (4) includes a first pipeline (40), a second pipeline (41) and a third pipeline (42). The first pipeline (40) is connected to the output end of the liquid drive pre-test module (1), the second pipeline (41) is connected to the output end of the electric drive pre-test module (2), and the third pipeline (42) is used to access the formation.

10. A dual-mode formation pressure testing method for a formation tester, characterized in that, A dual-mode formation pressure testing device based on any one of claims 1-9 includes the following steps: When testing the formation permeability of high-permeability formations and conventional-permeability formations, the control system (3) activates only the liquid-driven pre-test module (1). The liquid-driven pre-test module (1) draws formation fluid through the fluid pipeline (4). Based on the actual drawing volume and drawing speed of the liquid-driven pre-test module (1) and the pressure in the fluid pipeline (4) collected by the pressure gauge (5), the formation permeability is obtained using the formation fluid calculation method. When testing the formation permeability of low-permeability formations, the control system (3) activates only the electric drive pre-test module (2), which draws formation fluid through the fluid pipeline (4). Based on the actual drawing volume and drawing speed of the electric drive pre-test module (2), and the pressure in the fluid pipeline (4) collected by the pressure gauge (5), the formation permeability is obtained using the formation fluid calculation method.

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