Borehole wall stability testing device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
Smart Images
Figure CN122106576A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to wellbore testing devices, and more specifically, to a wellbore stability testing device. Background Technology
[0002] In oil drilling, wellbore pressure imbalance is a significant cause of wellbore instability. During drilling operations, mud engineers typically adjust mud density based on formation conditions to ensure that wellbore pressure is approximately equal to formation pressure. This is to prevent blowouts and to prevent drilling safety accidents such as wellbore collapse, wellbore shrinkage, and stuck pipe caused by pressure imbalance. Therefore, testing the coupling between wellbore pressure and formation pressure based on actual well conditions is essential for preventing drilling accidents and improving drilling productivity.
[0003] Currently, most wellbore stability tests focus on simulating formation conditions such as wellbore temperature and pressure, and testing the changes in the wellbore diameter under these conditions. While this method can test wellbore changes to some extent, it cannot test the coupling between the influent and the formation, thus failing to accurately study the wellbore instability mechanism and consequently, fail to accurately predict wellbore stability, and cannot provide sufficient theoretical guidance for drilling operations. Summary of the Invention
[0004] One technical problem to be solved by the present invention is to provide a wellbore stability testing device that can provide accurate data support for the drilling process and reduce safety accidents caused by improper wellbore pressure control.
[0005] To address the aforementioned technical problems, this invention provides a wellbore stability testing device, comprising a simulated wellbore, a wellbore fluid supply assembly, a pressurization assembly, and a backpressure assembly. The backpressure assembly includes a backpressure valve and a formation fluid container. The simulated wellbore forms a formation pressure simulation chamber and a wellbore pressure simulation chamber. The pressurization assembly is used to inject simulated formation water into the formation pressure simulation chamber. The wellbore fluid supply assembly is used to inject drilling fluid into the wellbore pressure simulation chamber. The backpressure valve is connected between the formation fluid container and the formation pressure simulation chamber, and a backpressure valve control unit is connected to the backpressure valve to control the opening and closing of the backpressure valve based on the pressure difference between the formation pressure simulation chamber and the wellbore pressure simulation chamber.
[0006] In some embodiments, the wellbore stability testing device further includes a simulated formation disposed in the simulated wellbore to form the wellbore pressure simulation chamber in conjunction with the simulated wellbore.
[0007] In some embodiments, the pressurization assembly includes a formation pressure boosting pump and a formation pressurization intermediate container. The formation pressure boosting pump is connected to the formation pressure simulation chamber through the formation pressurization intermediate container, and the back pressure valve control unit is connected between the formation pressure boosting pump and the back pressure valve to control the opening and closing of the back pressure valve by receiving liquid injected by the formation pressure boosting pump.
[0008] In some embodiments, a formation pressure monitoring sensor is installed on the pipeline between the formation pressurization intermediate container and the formation pressure simulation chamber, and a back pressure monitoring sensor is installed on the pipeline between the formation pressure boosting pump and the control port of the back pressure valve.
[0009] In some embodiments, the system further includes a formation pressure control valve disposed on a pipeline between the formation pressure booster pump and the formation pressurization intermediate container, a back pressure control valve disposed on a pipeline between the formation pressure booster pump and the hydraulic control port of the back pressure valve, a formation fluid outlet valve disposed on a pipeline between the back pressure valve and the formation pressure simulation chamber, and a formation pressure inlet valve disposed between the formation pressurization intermediate container and the formation pressure simulation chamber.
[0010] In some embodiments, the wellbore fluid supply assembly includes a wellbore pressure boosting pump and a wellbore pressurization intermediate container, wherein the wellbore pressure boosting pump is connected to the wellbore pressure simulation chamber through the wellbore pressurization intermediate container.
[0011] In some embodiments, the wellbore fluid column pressure circulation assembly is further included for driving the drilling fluid circulation movement within the wellbore pressure simulation chamber, wherein the two ends of the wellbore fluid column pressure circulation assembly are respectively connected to the two ends of the wellbore pressure simulation chamber.
[0012] In some embodiments, the wellbore fluid column pressure circulation assembly includes a reciprocating pump drive, a reciprocating pump, a first three-way directional valve, and a second three-way directional valve. The upper and lower ends of the wellbore pressure simulation chamber are respectively connected to a first pipeline and a second pipeline. The first three-way directional valve connects the first pipeline and the rod chamber and rodless chamber of the reciprocating pump. The first three-way directional valve is used to control the first pipeline to communicate with the rod chamber or rodless chamber of the reciprocating pump. The second three-way directional valve connects the second pipeline and the rod chamber and rodless chamber of the reciprocating pump. The second three-way directional valve is used to control the second pipeline to communicate with the rod chamber or rodless chamber of the reciprocating pump.
[0013] In some embodiments, the wellbore stability testing device further includes an exhaust valve disposed at the upper part of the simulated wellbore and a drain valve disposed at the lower part of the simulated wellbore, wherein both the exhaust valve and the drain valve are connected to the wellbore pressure simulation chamber.
[0014] In some embodiments, the wellbore stability testing device further includes an overburden pressure boosting pump, an overburden pressure simulation chamber is formed between the simulated formation and the upper end cap of the simulated wellbore, and the overburden pressure boosting pump is connected to the overburden pressure simulation chamber.
[0015] In some embodiments, an overburden pressure monitoring sensor is provided on the pipeline between the overburden pressure boosting pump and the overburden pressure simulation chamber, and a simulated wellbore pressure monitoring sensor is provided on the pipeline between the wellbore fluid supply assembly and the wellbore pressure simulation chamber.
[0016] In some embodiments, the wellbore stability testing device further includes a pressure block pressed onto the simulated formation and a displacement sensor abutting against the pressure block.
[0017] In some embodiments, the wellbore stability testing apparatus further includes a heater covering the simulated wellbore.
[0018] In some embodiments, the simulated wellbore includes a simulated wellbore outer cylinder, a screen pipe, a simulated wellbore upper cover, and a simulated wellbore lower cover. The simulated wellbore upper cover and the simulated wellbore lower cover are respectively disposed at the upper and lower ends of the simulated wellbore outer cylinder to form an assembly cavity. The screen pipe is disposed in the assembly cavity, and the formation pressure simulation cavity is formed between the screen pipe and the simulated wellbore outer cylinder. The simulated formation is disposed in the screen pipe.
[0019] Through the above technical solution, the wellbore stability testing device of the present invention sets up a simulated formation inside the simulated wellbore, forms a wellbore pressure simulation chamber, and forms a formation pressure simulation chamber. Simulated formation water is injected into the formation pressure simulation chamber through a pressurizing component, and drilling fluid is injected into the wellbore pressure simulation chamber through a wellbore fluid supply component. According to the actual drilling conditions, the pressure of the formation pressure simulation chamber and the wellbore pressure simulation chamber are adjusted by the pressurizing component and the wellbore fluid supply component respectively, so that the formation pressure simulation chamber and the wellbore pressure simulation chamber form a predetermined pressure difference that matches the actual drilling conditions. The back pressure valve is opened by the back pressure valve control unit, and the simulated formation water in the formation pressure simulation chamber flows into the formation fluid container through the back pressure valve. The volume of simulated formation water in the formation fluid container is measured to obtain positive filtration. By controlling the pressure of the wellbore pressure simulation chamber, the minimum permeability pressure difference is obtained, which provides accurate data support for drilling control during the drilling process and reduces drilling safety accidents such as wellbore collapse, wellbore diameter reduction, stuck drill, and drill bit burial caused by wellbore instability due to improper wellbore pressure control.
[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description
[0021] Figure 1This is a schematic diagram of a wellbore stability testing device according to a specific embodiment of the present invention;
[0022] Figure 2 This is a schematic diagram of a simulated wellbore according to a specific embodiment of the present invention.
[0023] Explanation of reference numerals in the attached figures
[0024] 1. Simulated wellbore; 101. Simulated wellbore outer cylinder; 102. Screen pipe; 103. Simulated wellbore top cover; 104. Simulated wellbore bottom cover; 2. Simulated formation; 3. Wellbore fluid supply assembly; 301. Wellbore pressure booster pump; 302. Wellbore pressurization intermediate container; 4. Pressurization assembly; 401. Formation pressure booster pump; 402. Formation pressurization intermediate container; 5. Backpressure assembly; 501. Backpressure valve; 502. Formation fluid container; 6. Formation pressure simulation chamber; 7. Wellbore pressure simulation chamber; 8. Wellbore fluid column pressure circulation assembly; 801. Reciprocating pump drive motor; 802. Reciprocating pump; 803. First three-way directional valve; 804. 901. Three-way reversing valve; 902. First pipeline; 903. Second pipeline; 10. Exhaust valve; 11. Drain valve; 12. Overburden pressure boosting pump; 13. Overburden pressure simulation chamber; 14. Overburden pressure monitoring sensor; 15. Simulated wellbore pressure monitoring sensor; 16. Formation pressure monitoring sensor; 17. Back pressure monitoring sensor; 18. Formation pressure control valve; 19. Back pressure control valve; 20. Formation fluid outlet valve; 21. Formation pressure inlet valve; 22. Pressure block; 23. Displacement sensor; 24. Heater; 25. Formation pressurization intermediate container drain valve; 26. Overburden pressure relief valve; 27. Wellbore pressure relief valve. Detailed Implementation
[0025] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
[0026] These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values set forth in these embodiments should be interpreted as merely exemplary and not as limiting.
[0027] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0028] Furthermore, the terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible range of error. "Parallel" is not strictly parallel, but within the permissible range of error. Terms such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.
[0029] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.
[0030] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this invention pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.
[0031] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.
[0032] like Figure 1 and Figure 2As shown, the wellbore stability testing device of the present invention includes a simulated wellbore 1, a wellbore fluid supply assembly 3, a pressurization assembly 4, and a backpressure assembly 5. The backpressure assembly 5 includes a backpressure valve 501 and a formation fluid container 502. The simulated wellbore 1 forms a formation pressure simulation chamber 6 and a wellbore pressure simulation chamber 7. The pressurization assembly 4 is used to inject simulated formation water into the formation pressure simulation chamber 6, and the wellbore fluid supply assembly 3 is used to inject drilling fluid into the wellbore pressure simulation chamber 7. The backpressure valve 501 is connected between the formation fluid container 502 and the formation pressure simulation chamber 6, and a backpressure valve control unit is connected to the backpressure valve 501 to control the opening and closing of the backpressure valve 501 according to the pressure difference between the formation pressure simulation chamber 6 and the wellbore pressure simulation chamber 7. In this embodiment of the wellbore stability testing device, a simulated formation 2 is added into the simulated wellbore 1. A formation pressure simulation chamber 6 is located outside the simulated formation 2, and a wellbore pressure simulation chamber 7 is located inside the simulated formation 2. Simulated formation water is injected into the formation pressure simulation chamber 6 through the pressurization component 4 to match the pressure in the formation pressure simulation chamber 6 with the actual formation pressure during drilling. Drilling fluid is injected into the wellbore pressure simulation chamber 7 through the wellbore fluid supply component 3 to match the pressure in the wellbore pressure simulation chamber 7 with the actual wellbore pressure during drilling. This allows the formation pressure simulation chamber 6 and the wellbore pressure simulation chamber to achieve the desired stability. A pressure difference matching the actual drilling conditions is formed between the simulated chambers 7. The back pressure valve 501 is opened via the back pressure valve control unit, allowing simulated formation water in the formation pressure simulation chamber 6 to flow into the formation fluid container 502. Positive filtration is achieved by measuring the volume of simulated formation water in the formation fluid container 502. The wellbore pressure simulation chamber 7 is adjusted via the wellbore supply assembly 3 to obtain the minimum permeability pressure difference, providing accurate data support for drilling pressure control during the drilling process. This reduces drilling safety accidents such as wellbore collapse, stuck pipe, and burial caused by instability due to improper wellbore pressure control. In some preferred embodiments, the formation fluid container 502 is a measuring cup to facilitate measuring the volume of simulated formation water flowing out of the formation pressure simulation chamber 6.
[0033] In some embodiments, such as Figure 1 As shown, the wellbore stability testing device also includes a simulated formation 2, which is set in the simulated wellbore 1. The simulated wellbore 1 and the simulated formation 2 together form a wellbore pressure simulation chamber 7. The formation pressure simulation chamber 6 is located outside the simulated formation 2. After the formation pressure simulation chamber 6 is injected with simulated formation water, it applies radial pressure to the simulated formation 2 to simulate the radial pressure of the formation on the wellbore. The wellbore pressure simulation chamber 7 is located inside the simulated formation 2. Drilling fluid is injected into the wellbore pressure simulation chamber 7 to simulate the wellbore pressure during drilling.
[0034] In some embodiments, such as Figure 1As shown, the pressurization assembly 4 includes a formation pressure boosting pump 401 and a formation pressurization intermediate container 402. The formation pressure boosting pump 401 is connected to the formation pressure simulation chamber 6 through the formation pressurization intermediate container 402. A backpressure valve control unit is connected between the formation pressure boosting pump 401 and the backpressure valve 501 to control the opening and closing of the backpressure valve 501 by receiving the liquid injected by the formation pressure boosting pump 401. In this embodiment, the formation pressure boosting pump 401 is connected to the bottom of the formation pressurization intermediate container 402. A first interface communicating with the formation pressure simulation chamber 6 is formed on the side of the simulated wellbore 1. The upper part of the formation pressurization intermediate container 402 is connected to the first interface. The formation pressure boosting pump 401 is connected to the backpressure valve 501 through the backpressure valve control unit. A second interface communicating with the formation pressure simulation chamber 6 is formed on the bottom surface of the simulated wellbore 1. The backpressure valve 501 is connected to the second interface. In some specific embodiments, the backpressure valve control unit controls the backpressure valve 501. The formation pressure booster pump 401 pumps simulated formation water into the control port of the back pressure valve 501. The simulated formation water pushes the valve core of the back pressure valve 501, causing the back pressure valve 501 to conduct, thus connecting the formation pressure simulation chamber 6 and the formation fluid container 502. The wellbore stability testing device in this embodiment also includes a back pressure control valve 19 and a formation fluid outlet valve 20. The back pressure control valve 19 is installed on the pipeline between the control port of the back pressure valve 501 and the formation pressure booster pump 401, and the formation fluid outlet valve is installed between the back pressure valve 501 and the second port.
[0035] In some embodiments, such as Figure 1 As shown, a formation pressure monitoring sensor 16 is installed on the pipeline between the formation pressurization intermediate container 402 and the formation pressure simulation chamber 6, and a back pressure monitoring sensor 17 is installed on the pipeline between the formation pressure boosting pump 401 and the control port of the back pressure valve 501. The formation pressure monitoring sensor 16 monitors the pressure inside the formation pressure simulation chamber 6 to facilitate precise adjustment of the pressure in the formation pressure simulation chamber 6, and the back pressure monitoring sensor 17 monitors the pressure at the control port of the back pressure valve 501. In some embodiments, the wellbore stability testing device of the present invention can adjust the pressure of the wellbore pressure simulation chamber 7 through the wellbore pressure boosting pump 301, and observe the change in pressure of the formation pressure simulation chamber 6 with the pressure of the wellbore pressure simulation chamber 7 through the simulated wellbore pressure monitoring sensor 15 and the formation pressure monitoring sensor 16, and determine the control range of wellbore pressure during drilling operations based on this change.
[0036] In some embodiments, such as Figure 1As shown, the wellbore stability testing device of this embodiment also includes a formation pressure control valve 18 disposed on the pipeline between the formation pressure boosting pump 401 and the formation pressurization intermediate container 402, a back pressure control valve 19 disposed on the pipeline between the formation pressure boosting pump 401 and the hydraulic control port of the back pressure valve 501, a formation fluid outlet valve 20 disposed on the pipeline between the back pressure valve 501 and the formation pressure simulation chamber 6, and a formation pressure inlet valve 21 disposed between the formation pressurization intermediate container 402 and the formation pressure simulation chamber 6. When the wellbore stability testing device of this embodiment is tested, the formation pressure control valve 18 is first opened, and simulated formation water is injected into the formation pressurization intermediate container 402 through the formation pressure booster pump 401. After the formation pressurization intermediate container 402 is filled with simulated formation water, the formation fluid outlet valve 20 is opened, so that the formation pressure booster pump 401 injects simulated formation water into the formation pressure simulation chamber 6. After adjusting the pressure difference between the formation pressure simulation chamber 6 and the wellbore pressure simulation chamber 7, the back pressure control valve 19 is opened, and the formation pressure booster pump 401 delivers simulated formation water to the control port of the back pressure valve 501, pushing the valve core of the back pressure valve 501 to make the back pressure valve 501 conduct. Then the formation fluid outlet valve 20 is opened, so that the formation pressure simulation chamber 6 is connected to the formation pressurization intermediate container 402.
[0037] In some embodiments, such as Figure 1 As shown, the wellbore fluid supply assembly 3 includes a wellbore pressure boosting pump 301 and a wellbore pressurization intermediate container 302. The wellbore pressure boosting pump 301 is connected to the wellbore pressure simulation chamber 7 through the wellbore pressurization intermediate container 302. When the wellbore stability testing device in this embodiment is tested, drilling fluid is injected into the wellbore pressurization intermediate container 302 through the wellbore pressure boosting pump 301. After the wellbore pressurization intermediate container 302 is full, drilling fluid is injected into the wellbore pressure simulation chamber 7 through the wellbore pressurization intermediate container 302 and the wellbore pressure boosting pump 301.
[0038] In some embodiments, such as Figure 1 As shown, the wellbore stability testing device of this embodiment also includes a wellbore fluid column pressure circulation component 8 for driving the drilling fluid circulation movement within the wellbore pressure simulation chamber 7. The two ends of the wellbore fluid column pressure circulation component 8 are respectively connected to the two ends of the wellbore pressure simulation chamber 7. The wellbore stability testing device of this embodiment can drive the drilling fluid to circulate within the wellbore pressure simulation chamber 7 through the wellbore fluid column pressure circulation component 8, thereby simulating the circulation of drilling fluid in the wellbore under actual drilling conditions, further improving the simulation effect and the accuracy of the simulation results.
[0039] In some embodiments, such as Figure 1As shown, the wellbore fluid column pressure circulation assembly 8 includes a reciprocating pump drive 801, a reciprocating pump 802, a first three-way reversing valve 803, and a second three-way reversing valve 804. The upper and lower ends of the wellbore pressure simulation chamber 7 are respectively connected to a first pipeline 901 and a second pipeline 902. The first three-way reversing valve 803 connects the first pipeline 901 and the rod chamber and rodless chamber of the reciprocating pump 802. The first three-way reversing valve 803 is used to control the communication between the first pipeline 901 and the rod chamber or rodless chamber of the reciprocating pump 802. The second three-way reversing valve 804 connects the second pipeline 902 and the rod chamber and rodless chamber of the reciprocating pump 802. The second three-way reversing valve 804 is used to control the communication between the second pipeline 902 and the rod chamber or rodless chamber of the reciprocating pump 802. In this embodiment, the reciprocating pump 802 is filled with drilling fluid, and the piston rod of the reciprocating pump 802 is driven to extend and retract by the reciprocating pump drive 801. In some embodiments, such as... Figure 1 As shown, when the piston rod of the reciprocating pump 802 retracts, the first three-way directional valve 803 is controlled to connect the rodless chamber of the reciprocating pump 802 to the upper end of the wellbore pressure simulation chamber 7, and the second three-way directional valve 804 is controlled to connect the rod chamber of the reciprocating pump 802 to the lower end of the wellbore pressure simulation chamber 7. Thus, drilling fluid flows out from the rodless chamber of the reciprocating pump 802, passes through the first three-way directional valve 803, flows into the upper end of the wellbore pressure simulation chamber 7, flows out from the lower end of the wellbore pressure simulation chamber 7, and finally flows into the rod chamber of the reciprocating pump 802. The piston of the reciprocating pump 802... When the rod extends, the first three-way directional valve 803 is controlled to connect the rod chamber of the reciprocating pump 802 to the upper end of the wellbore pressure simulation chamber 7. The second three-way directional valve 804 is controlled to connect the rodless chamber of the reciprocating pump 802 to the lower end of the wellbore pressure simulation chamber 7. As a result, the drilling fluid flows out from the rod chamber of the reciprocating pump 802, passes through the second three-way directional valve 804, flows into the upper end of the wellbore pressure simulation chamber 7, flows out from the lower end of the wellbore pressure simulation chamber 7, and finally flows into the rodless chamber of the reciprocating pump 802, thereby realizing the circulation of drilling fluid in the wellbore pressure simulation chamber 7.
[0040] In some embodiments, such as Figure 1 As shown, the wellbore stability testing device in this embodiment also includes an exhaust valve 10 disposed on the upper part of the simulated wellbore 1 and a drain valve 11 disposed on the lower part of the simulated wellbore 1. When the wellbore stability testing device in this embodiment is tested, drilling fluid is filled into the wellbore pressurization intermediate container 302 and the reciprocating pump 802. The exhaust valve 10 is opened, and drilling fluid is injected into the wellbore pressure simulation chamber 7 through the wellbore pressurization intermediate container 302 and the wellbore pressure boosting pump 301 until drilling fluid overflows from the exhaust valve 10 on the upper part of the simulated wellbore 1. Then the exhaust valve 10 is closed. The exhaust valve 10 facilitates the filling of the wellbore pressure simulation chamber 7 with drilling fluid.
[0041] In some embodiments, such as Figure 1As shown, the wellbore stability testing device of this embodiment also includes an overburden pressure boosting pump 12. An overburden pressure simulation chamber 13 is formed between the upper end cap of the simulated formation 2 and the simulated wellbore 1. The overburden pressure boosting pump 12 is connected to the overburden pressure simulation chamber 13. The overburden pressure simulation chamber 13 is formed between the upper end of the simulated formation 2 and the simulated wellbore 1. The overburden pressure boosting pump 12 is connected to the overburden pressure simulation chamber 13. By controlling the overburden pressure boosting pump 12 to change the pressure of the overburden pressure simulation chamber 13, overburden pressure is applied to the simulated formation 2, thereby simulating the formation overburden pressure under actual drilling conditions, further improving the simulation effect and increasing the accuracy of the test results.
[0042] In some embodiments, such as Figure 1 and Figure 2 As shown, an overburden pressure monitoring sensor 14 is installed on the pipeline between the overburden pressure boosting pump 12 and the overburden pressure simulation chamber 13, and a simulated wellbore pressure monitoring sensor 15 is installed on the pipeline between the wellbore fluid supply assembly 3 and the wellbore pressure simulation chamber 7. The wellbore stability testing device of this embodiment monitors the pressure of the overburden pressure simulation chamber 13 through the overburden pressure monitoring sensor 14, so as to accurately control the pressure of the overburden pressure simulation chamber 13, which is beneficial to accurately simulate the actual drilling conditions. The simulated wellbore pressure monitoring sensor 15 monitors the pressure of the wellbore pressure simulation chamber 7, so as to accurately control the pressure of the wellbore pressure simulation chamber 7, which is beneficial to accurately simulate the actual drilling conditions, facilitates the calculation of the minimum pressure difference for reverse permeation, provides accurate data support for drilling pressure control during the drilling process, and reduces drilling safety accidents such as wellbore collapse, wellbore diameter reduction, stuck drill, and drill bit burial caused by wellbore instability due to improper wellbore pressure control.
[0043] In some embodiments, such as Figure 1 As shown, the wellbore stability testing device in this embodiment also includes a pressure block 22 pressed onto the simulated formation 2 and a displacement sensor 23 abutting against the pressure block 22. The pressure of the overburden pressure simulation chamber 13 is increased by the overburden pressure boosting pump 12 to apply axial pressure to the pressure block 22 to simulate the overburden pressure of the formation. The axial movement of the pressure block 22 is detected by the displacement sensor 23, thereby simulating the height change of the wellbore under the action of axial pressure, that is, simulating the formation expansion in actual drilling conditions.
[0044] In some embodiments, such as Figure 1 and Figure 2 As shown, the wellbore stability testing device of this embodiment also includes a heater 24 covering the simulated wellbore 1. When the wellbore stability testing device of this embodiment is tested, the heater heats the simulated wellbore 1 to simulate the formation temperature, thereby further improving the simulation effect and the accuracy of the simulation results.
[0045] In some embodiments, such as Figure 1 As shown, the simulated wellbore 1 includes a simulated wellbore outer cylinder 101, a screen pipe 102, a simulated wellbore upper cover 103, and a simulated wellbore lower cover 104. The simulated wellbore upper cover 103 and the simulated wellbore lower cover 104 are respectively disposed at the upper and lower ends of the simulated wellbore outer cylinder 101 to form an assembly cavity. The screen pipe 102 is disposed in the assembly cavity. A formation pressure simulation cavity 6 is formed between the screen pipe 102 and the simulated wellbore outer cylinder 101. The simulated formation 2 is disposed in the screen pipe 102. In this embodiment, the screen pipe 102, the simulated formation 2, and the simulated wellbore cover 103 cooperate to form an overburden pressure simulation chamber 13. A guide post is formed on the side of the simulated wellbore cover 103 near the simulated formation 2. The pressure block 22 is an annular pressure block. The outer ring surface of the annular pressure block is attached to the inner wall surface of the screen pipe 102, and the inner ring surface of the annular pressure block is attached to the guide post of the simulated wellbore cover 103. The heater 204 is covered on the simulated wellbore outer cylinder 101. The simulated wellbore cover 103 and the simulated wellbore lower cover 104 are both formed with mounting structures for fixing the simulated wellbore outer cylinder 101 and the screen pipe 102. After the simulated wellbore outer cylinder 101, screen pipe 102, simulated wellbore upper cover 103, and simulated wellbore lower cover 104 are installed, the simulated wellbore outer cylinder 101, screen pipe 102, simulated wellbore upper cover 103, and simulated wellbore lower cover 104 cooperate to form a formation pressure simulation chamber 6.
[0046] This invention provides a wellbore stability testing device, such as... Figure 1 and 2As shown, the wellbore stability testing device includes a simulated wellbore 1, a simulated formation 2, a wellbore fluid supply assembly 3, a pressurization assembly 4, a backpressure assembly 5, a wellbore fluid column pressure circulation assembly 8, a first pipeline 901, a second pipeline 902, an overburden pressure boosting pump 12, a pressure block 22, and a heater 24. The simulated wellbore 1 includes a simulated wellbore outer cylinder 101, a screen pipe 102, a simulated wellbore upper cover 103, and a simulated wellbore lower cover 104. The simulated wellbore upper cover 103 and the simulated wellbore lower cover 104 are respectively installed at the upper and lower ends of the screen pipe 102. The heater 24 covers the simulated wellbore outer cylinder 101. The simulated wellbore outer cylinder 101 is located outside the screen pipe 102, so that a formation pressure simulation chamber 6 is formed between the simulated wellbore outer cylinder 101 and the screen pipe 102. The upper end of the formation pressurization intermediate container 402 is connected to the formation pressure simulation chamber 6, and the lower end of the formation pressurization intermediate container 402 is connected to the formation pressure boosting pump 401. A formation pressure control valve 18 is installed between the formation pressure boosting pump 401 and the formation pressurization intermediate container 402. A formation pressure monitoring sensor 16 and a formation pressure inlet valve 21 are installed between the formation pressurization intermediate container 402 and the formation pressure simulation chamber 6. The formation fluid container 502 is connected to the formation pressure simulation chamber 6 through a back pressure valve 501. A formation fluid outlet valve 20 is installed between the formation pressure simulation chamber 6 and the back pressure valve 501. The formation pressure boosting pump 401 is connected to the control port of the back pressure valve 501. A back pressure monitoring sensor 17 and a back pressure control valve 19 are installed between the formation pressure boosting pump 401 and the back pressure valve 501. The simulated formation 2 is set inside the screen pipe 102, so that the simulated formation 2, screen pipe 102, and simulated wellbore cover 403 cooperate to form an overburden pressure simulation chamber 13. A pressure block 22 is set inside the overburden pressure simulation chamber 13. An overburden pressure boosting pump 12 is connected to the overburden pressure simulation chamber 13. An overburden pressure monitoring sensor 14 and an overburden pressure relief valve 26 are set between the overburden pressure boosting pump 12 and the overburden pressure simulation chamber 13. A displacement sensor 23 is also set on the upper surface of the simulated wellbore cover 403, and the wire of the displacement sensor 23 abuts against the pressure block 22. The simulated formation 2, simulated wellbore cover 403, and simulated wellbore lower cover 404 cooperate to form a wellbore pressure simulation chamber 7. The simulated wellbore cover 403 and simulated wellbore lower cover 404 form an upper cover interface and a lower cover interface, respectively. The upper cover interface is connected to an exhaust valve 10, and the lower cover interface is connected to a drain valve 11. The wellbore fluid supply assembly 3 includes a wellbore pressure boosting pump 301 and a wellbore pressurization intermediate container 302. The lower end of the wellbore pressurization intermediate container 302 is connected to the wellbore pressure boosting pump 301, and the upper end of the wellbore pressurization intermediate container 302 is connected to the lower cover interface.The wellbore fluid column pressure circulation assembly 8 includes a reciprocating pump drive 801, a reciprocating pump 802, a first three-way reversing valve 803, and a second three-way reversing valve 804. The upper cover interface and the lower cover interface are respectively connected to the first pipeline 901 and the second pipeline 902. The first three-way reversing valve 803 connects the first pipeline 901 and the rod chamber and rodless chamber of the reciprocating pump 802. The first three-way reversing valve 803 is used to control the communication between the first pipeline 901 and the rod chamber or rodless chamber of the reciprocating pump 802. The second three-way reversing valve 804 connects the second pipeline 902 and the rod chamber and rodless chamber of the reciprocating pump 802. The second three-way reversing valve 804 is used to control the communication between the second pipeline 902 and the rod chamber or rodless chamber of the reciprocating pump 802. A simulated wellbore pressure monitoring sensor 15 is connected to the first pipeline 901. Wellbore pressure booster pump 301, formation pressure booster pump 401 and overburden pressure booster pump 12 are respectively connected to wellbore pressure relief valve 27, formation pressurization intermediate container drain valve 25 and overburden pressure relief valve 26. During testing with the wellbore stability testing device in this embodiment, the formation pressure control valve 18 and formation pressure inlet valve 21 are first opened. Simulated formation water is injected into the formation pressure simulation chamber 6 through the formation pressure booster pump 401 and the formation pressurization intermediate container 402 to simulate radial pressurization of the simulated wellbore 1 under actual drilling conditions. Drilling fluid is then injected into the wellbore pressure simulation chamber 7 through the wellbore pressure booster pump 301 and the wellbore pressurization intermediate container 302. When injecting drilling fluid into the wellbore pressure simulation chamber 7, the vent valve 10 is opened to expel air from the circulation pipeline. After drilling fluid overflows from the vent valve 10, the vent valve is closed to ensure that the circulation pipeline is filled with drilling fluid. The simulated wellbore 1 is then heated by the heater 24 to simulate the formation temperature under actual drilling conditions. Simulated formation water is injected into the overburden pressure simulation chamber 13 through the overburden pressure booster pump 12. The pressure in the overburden pressure simulation chamber 13 is monitored by the overburden pressure monitoring sensor 14 to simulate the actual drilling conditions. Axial pressure is applied to the simulated wellbore 1, and the axial displacement of the pressure block 22 is monitored by the displacement sensor 23 to predict the formation expansion during actual drilling. Then, the drilling fluid circulation in the wellbore pressure simulation chamber 7 is controlled by the wellbore fluid column pressure circulation assembly 8 to simulate the flow of drilling fluid in the wellbore during actual drilling. Based on the actual drilling conditions and the pressures of the wellbore pressure simulation chamber 7 and the formation pressure simulation chamber 6 monitored by the simulated wellbore pressure monitoring sensor 15 and the formation pressure monitoring sensor 16, a certain pressure difference is formed between the wellbore pressure simulation chamber 7 and the formation pressure simulation chamber 6 by the wellbore pressure boosting pump 301 and the formation pressure boosting pump 401. The back pressure control valve 19 and the formation fluid outlet valve 20 are opened, and the formation pressure boosting pump 401 applies a certain pressure to the control port of the back pressure valve 501, so that the formation pressure simulation chamber 6 is connected to the formation fluid container 502, and the amount of simulated formation water discharged from the formation fluid container 502 is measured.After the simulated formation water output is measured, the formation fluid outlet valve 20 and the formation pressure inlet valve 21 are closed. The pressure inside the wellbore pressure simulation chamber 7 is changed by the wellbore pressure booster pump 301. The pressure changes in the formation pressure simulation chamber 6 with the pressure changes in the wellbore pressure simulation chamber 7 to determine the control range of wellbore pressure during drilling operations. After the test is completed, opening the drain valve 11, the formation pressurization intermediate container drain valve 25, the overburden pressure relief valve 26, and the wellbore pressure relief valve 27 allows the drilling fluid and simulated formation water in the wellbore stability testing device to be released.
[0047] Based on the wellbore stability testing device mentioned in the above technical solution of the present invention, the present invention further provides a wellbore stability testing method, comprising the following steps:
[0048] (A) Fill the reciprocating pump 802 and the wellbore pressurization intermediate container 302 with drilling fluid, and fill the formation pressurization intermediate container 402 with simulated formation water;
[0049] (B) Open the vent valve 10 and inject drilling fluid into the well pressure simulation chamber 7 through the well pressurization intermediate container 302 and the well pressure boosting pump 301 until the drilling fluid overflows from the vent valve 10, and then close the vent valve 10.
[0050] (C) Turn on heater 24 to heat the simulated wellbore 1, apply overburden pressure to simulated formation 2 through overburden pressure boosting pump 12, and monitor the height change of simulated formation 2 through displacement sensor;
[0051] (D) Start the wellbore fluid column pressure circulation assembly 8 to circulate the drilling fluid in the wellbore pressure simulation chamber, start the wellbore pressure booster pump 301 to establish the pressure in the wellbore pressure simulation chamber 7, start the formation pressure booster pump 401, open the formation pressure control valve 18 and the formation pressure inlet valve 21 to establish the pressure in the formation pressure simulation chamber 6, and make the wellbore pressure simulation chamber 7 and the formation pressure simulation chamber 6 have a predetermined pressure difference according to the actual drilling conditions, open the back pressure control valve 19 and the formation fluid outlet valve 20 to make the back pressure valve 501 conduct, and use the formation fluid container 502 to measure the amount of simulated formation water discharged at the outlet of the back pressure valve 501.
[0052] (E) Close the formation fluid outlet valve 20 and the formation pressure inlet valve 21, change the pressure of the wellbore pressure simulation chamber 7 by using the wellbore pressure booster pump 301, and observe the change of the pressure of the formation pressure simulation chamber 6 with the pressure of the wellbore pressure simulation chamber 7 to determine the control range of the wellbore pressure during the drilling process.
[0053] As can be seen from the above description, the advantages of this invention are as follows: First, by setting up a backpressure valve and a formation fluid container, the forward filtration and minimum permeability pressure differential are tested, providing accurate data support for drilling pressure control during the drilling process, reducing drilling safety accidents such as wellbore collapse, wellbore shrinkage, and stuck drill bit due to wellbore instability caused by improper wellbore pressure control; Second, by applying pressure to the upper part of the simulated formation 2 through the overburden pressure boosting pump 12, the overburden pressure in the actual drilling situation is simulated, and the pressure in the wellbore pressure simulation chamber 7 is adjusted by the wellbore pressure boosting pump 301 to simulate the actual... The wellbore pressure during drilling is adjusted by the formation pressure booster pump 401 to adjust the pressure in the formation pressure simulation chamber 6, simulating the radial pressure of the formation on the wellbore in actual drilling conditions. The drilling fluid in the wellbore pressure simulation chamber 7 is circulated by a reciprocating valve, and the simulated wellbore is heated by a heater to simulate the wellbore temperature in actual drilling conditions. Thus, the wellbore stability testing device of the present invention can more realistically simulate actual drilling conditions and improve the accuracy of the test results. Third, by setting a displacement sensor to monitor the height change of the pressure block, the formation expansion under actual drilling conditions can be predicted.
[0054] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions of this invention based on the above description.
[0055] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.
Claims
1. A wellbore stability testing device, characterized in that, The system includes a simulated wellbore (1), a wellbore fluid supply assembly (3), a pressurization assembly (4), and a backpressure assembly (5). The backpressure assembly (5) includes a backpressure valve (501) and a formation fluid container (502). The simulated wellbore (1) forms a formation pressure simulation chamber (6) and a wellbore pressure simulation chamber (7). The pressurization assembly (4) is used to inject simulated formation water into the formation pressure simulation chamber (6). The wellbore fluid supply assembly (3) is used to inject drilling fluid into the wellbore pressure simulation chamber (7). The backpressure valve (501) is connected between the formation fluid container (502) and the formation pressure simulation chamber (6), and a backpressure valve control unit is connected to the backpressure valve (501) to control the opening and closing of the backpressure valve (501) according to the pressure difference between the formation pressure simulation chamber (6) and the wellbore pressure simulation chamber (7).
2. The wellbore stability testing device according to claim 1, characterized in that, It also includes a simulated formation (2), which is set in the simulated wellbore (1) to cooperate with the simulated wellbore (1) to form the wellbore pressure simulation cavity (7).
3. The wellbore stability testing device according to claim 1, characterized in that, The pressurization assembly (4) includes a formation pressure boosting pump (401) and a formation pressurization intermediate container (402). The formation pressure boosting pump (401) is connected to the formation pressure simulation chamber (6) through the formation pressurization intermediate container (402). The back pressure valve control unit is connected between the formation pressure boosting pump (401) and the back pressure valve (501) to control the opening and closing of the back pressure valve (501) by receiving the liquid injected by the formation pressure boosting pump (401).
4. The wellbore stability testing device according to claim 3, characterized in that, A formation pressure monitoring sensor (16) is installed on the pipeline between the formation pressurization intermediate container (402) and the formation pressure simulation chamber (6), and a back pressure monitoring sensor (17) is installed on the pipeline between the formation pressure boosting pump (401) and the control port of the back pressure valve (501).
5. The wellbore stability testing device according to claim 3, characterized in that, It also includes a formation pressure control valve (18) installed on the pipeline between the formation pressure booster pump (401) and the formation pressurization intermediate container (402), a back pressure control valve (19) installed on the pipeline between the formation pressure booster pump (401) and the hydraulic control port of the back pressure valve (501), a formation fluid outlet valve (20) installed on the pipeline between the back pressure valve (501) and the formation pressure simulation chamber (6), and a formation pressure inlet valve (21) installed between the formation pressurization intermediate container (402) and the formation pressure simulation chamber (6).
6. The wellbore stability testing device according to any one of claims 1 to 5, characterized in that, The wellbore fluid supply assembly (3) includes a wellbore pressure booster pump (301) and a wellbore pressurization intermediate container (302). The wellbore pressure booster pump (301) is connected to the wellbore pressure simulation chamber (7) through the wellbore pressurization intermediate container (302).
7. The wellbore stability testing device according to any one of claims 1 to 5, characterized in that, It also includes a wellbore fluid column pressure circulation assembly (8) for driving the drilling fluid circulation movement within the wellbore pressure simulation chamber (7), with both ends of the wellbore fluid column pressure circulation assembly (8) connected to both ends of the wellbore pressure simulation chamber (7).
8. The wellbore stability testing device according to claim 7, characterized in that, The wellbore fluid column pressure circulation assembly (8) includes a reciprocating pump drive (801), a reciprocating pump (802), a first three-way reversing valve (803), and a second three-way reversing valve (804). The upper and lower ends of the wellbore pressure simulation chamber (7) are respectively connected to a first pipeline (901) and a second pipeline (902). The first three-way reversing valve (803) connects the first pipeline (901) and the rod chamber and rodless chamber of the reciprocating pump (802). The first three-way reversing valve (803) is used to control the first pipeline (901) to communicate with the rod chamber or rodless chamber of the reciprocating pump (802). The second three-way reversing valve (804) connects the second pipeline (902) and the rod chamber and rodless chamber of the reciprocating pump (802). The second three-way reversing valve (804) is used to control the second pipeline (902) to communicate with the rod chamber or rodless chamber of the reciprocating pump (802).
9. The wellbore stability testing device according to claim 8, characterized in that, It also includes an exhaust valve (10) located on the upper part of the simulated wellbore (1) and a drain valve (11) located on the lower part of the simulated wellbore (1), both of which are connected to the wellbore pressure simulation chamber (7).
10. The wellbore stability testing device according to claim 2, characterized in that, It also includes an overburden pressure boosting pump (12), and an overburden pressure simulation chamber (13) is formed between the simulated formation (2) and the upper end cap of the simulated wellbore (1), and the overburden pressure boosting pump (12) is connected to the overburden pressure simulation chamber (13).
11. The wellbore stability testing device according to claim 10, characterized in that, An overburden pressure monitoring sensor (14) is installed on the pipeline between the overburden pressure boosting pump (12) and the overburden pressure simulation chamber (13), and a simulated wellbore pressure monitoring sensor (15) is installed on the pipeline between the wellbore fluid supply assembly (3) and the wellbore pressure simulation chamber (7).
12. The wellbore stability testing device according to claim 10, characterized in that, It also includes a pressure block (22) pressed on the simulated stratum (2) and a displacement sensor (23) abutting against the pressure block (22).
13. The wellbore stability testing device according to any one of claims 1 to 5, characterized in that, It also includes a heater (24) covering the simulated wellbore (1).
14. The wellbore stability testing device according to claim 2, characterized in that, The simulated wellbore (1) includes a simulated wellbore outer cylinder (101), a screen pipe (102), a simulated wellbore upper cover (103), and a simulated wellbore lower cover (104). The simulated wellbore upper cover (103) and the simulated wellbore lower cover (104) are respectively disposed at the upper and lower ends of the simulated wellbore outer cylinder (101) to form an assembly cavity. The screen pipe (102) is disposed in the assembly cavity. The formation pressure simulation cavity (6) is formed between the screen pipe (102) and the simulated wellbore outer cylinder (101). The simulated formation (2) is disposed in the screen pipe (102).