A device and method for testing physical and mechanical properties of a formation water thermal pressurization process

Abstract

The present application belongs to the technical field of petroleum engineering, and particularly relates to a device and method for testing physical and mechanical properties in a formation water thermal pressurization process. The device comprises a support, a computer system, a core pressing mold and a reaction kettle. The testing device further comprises an acoustic emission signal processing unit, a displacement sensor, a shaft pressure loader, a liquid supply and discharge device, a gas supply and discharge device, a temperature controller, a confining pressure controller and a pore pressure controller, and each component is controlled by the computer system. The testing method provided by the present application can simulate the actual situation of a formation, analyze the influence of temperature rise on pore pressure by using a cutting sample at a predetermined temperature and pressure, calculate the elastic modulus and Poisson's ratio, and predict the formation pressure. The device is simple to operate, can simulate the formation water thermal pressurization process, and has high data reliability.

Description

Technical Field

[0001] This invention belongs to the field of petroleum engineering technology, specifically relating to a testing device and method for testing the physical and mechanical properties of formation hydrothermal pressurization processes. Background Technology

[0002] With the continuous increase in my country's oil and gas exploration and development efforts, exploration targets have shifted to complex and deep areas. The number of oil and gas wells encountering abnormally high-pressure formations during drilling is also increasing. These abnormally high pressures impact drilling efficiency and safety, representing a key challenge in achieving safe and efficient drilling. Formation hydrothermal pressurization is one of the important causes of abnormally high pressures. Investigating the physical and mechanical properties of the formation hydrothermal pressurization process, analyzing the impact of temperature increases on pore pressure, and further exploring the changes in elastic modulus, Poisson's ratio, and acoustic parameters are crucial for understanding the hydrothermal pressurization process and improving exploration and development efficiency.

[0003] At present, there are no experimental instruments or methods for preparing experimental samples from rock cuttings, simulating the formation hydrothermal pressurization process, and fully analyzing the comprehensive impact of the temperature rise process on pore pressure, elastic mechanical parameters, and acoustic parameters. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a testing device and method for the physical and mechanical properties of formation hydrothermal pressurization processes. This device can simulate the formation hydrothermal pressurization process, analyze the effect of temperature rise on pore pressure using rock cuttings samples, and calculate the elastic modulus, Poisson's ratio, and predict formation pressure. The device is simple to operate and provides highly reliable data. The technical solution adopted is as follows: A testing device for the physical and mechanical properties of formation hydrothermal pressurization process includes a support, a computer system, a core pressing mold, and a reaction vessel. The support is provided with a base and a top cover, and a main body extending downward is provided in the center of the top cover. The testing device also includes an acoustic emission signal processing unit, a displacement sensor, an axial pressure loader, a liquid supply and discharge device, a gas supply and exhaust device, a temperature controller, a confining pressure controller, and a pore pressure controller. The axial pressure loader is installed on the platform at the bottom of the support, and the reaction vessel is installed on the axial pressure loader; the reaction vessel is a solid shell, and a plunger is installed in the opening at the center of the top of the shell. The interior is a hollow cavity, and the plunger is vertically installed below the top cover of the support by a fixing component. The axial pressure loader and the outer shell of the reactor are both connected to the liquid supply and discharge device, the axial pressure controller, and the confining pressure controller via pipelines; an acoustic signal probe and a temperature controller probe are installed on the inner wall of the reactor. The acoustic signal probe is connected to the acoustic emission signal processor via a pipeline, and the temperature controller probe is connected to the temperature controller via a pipeline. The inner cavity of the reactor is equipped with a core holder that can compress rock cuttings into cores. The inner cavity is also equipped with pipelines that connect to a vacuum pump and are connected in parallel to a gas supply and exhaust device, a pore pressure controller, and radial and axial displacement sensors. The reactor, acoustic emission signal processing unit, displacement sensor, axial pressure loader, liquid supply and discharge device, gas supply and exhaust device, temperature controller, confining pressure controller, and pore pressure controller are all connected to the computer system.

[0005] Preferably, the contact area between the reactor and the plunger is sealed, and sealing rings are installed at the connection points between each pipeline and the shell.

[0006] Preferably, the core holder includes an upper plunger, a pipe diameter, and a lower plunger; the connection ends of the radial and axial displacement sensor pipelines are installed on the pipe diameter.

[0007] Preferably, a vent hole is provided in the center of both the upper and lower plungers. The vent hole is connected to a vacuum pump and is also connected in parallel to the pipelines of the air supply and exhaust device and the pore pressure controller.

[0008] Preferably, an automatic valve is installed on the pipeline connecting the vent hole of the upper plunger and the lower plunger. The automatic valve is connected to a computer system via a wireless remote control device. The computer system can control its opening and closing. Controlling the vent hole to close can achieve the sealing of pore pressure.

[0009] A method for testing the physical and mechanical properties of a formation hydrothermal pressurization process, using the aforementioned testing device for the physical and mechanical properties of a formation hydrothermal pressurization process, the method comprising the following steps: S1. The pipe diameter of the core holder is connected to the radial and axial displacement sensors, and the vent holes on the upper and lower core plungers are connected to the pipelines of the vacuum pump. S2. Install the lower core plunger, install an oil-separating sleeve and a thermoplastic tube along the diameter of the core holder, then load the rock cutting sample, cover it with the upper core plunger, control the axial pressure loader to apply axial pressure, lift the reactor upward, and insert the plunger into the inner cavity of the reactor to press the rock cutting sample and press it into a standard core for experiment. S3. Vacuum the core sample using a vacuum pump; S4. Apply a predetermined amount of axial pressure, confining pressure, and pore pressure to the core sample using a computer-controlled axial pressure loader, confining pressure controller, and pore pressure controller; control the core sample to a specified temperature using a temperature controller; S5. Maintain axial pressure and confining pressure constant, and close the gas inlet and outlet channels of the core sample through the pore pressure controller to achieve pore pressure closure; S6. Adjust the rock sample temperature using a temperature controller. As the temperature rises, the pore pressure, radial and axial deformation, and acoustic parameters of the core sample change. Record the changes in the data. S7. Analyze the effect of temperature rise on pore pressure, and further calculate the elastic modulus and Poisson's ratio based on radial and axial deformation; predict formation pressure based on changes in acoustic parameters.

[0010] Preferably, in step S6, the temperature of the reactor is increased by a temperature controller, and the pore pressure of the core sample increases accordingly. The values ​​of the axial stress increment and axial strain increment can be obtained using radial and axial displacement sensors, allowing for the calculation of the elastic modulus. The formula for calculating the elastic modulus is: ; In the formula, E is the elastic modulus, in MPa; -Axial stress increment, MPa; - Axial strain increment.

[0011] Preferably, in step S6, the temperature of the reactor is increased by a temperature controller, and the pore pressure of the core sample increases accordingly. The values ​​of the axial strain increment and radial strain increment can be obtained using radial and axial displacement sensors, allowing for the calculation of the Poisson's ratio of the rock. The formula for calculating the Poisson's ratio of the rock is as follows: ; In the formula, - Poisson's ratio of rocks; - Axial strain increment; - Radial strain increment.

[0012] Preferably, in step S6, the confining pressure and pore pressure borne by the rock core are measured, and the acoustic emission curve of each rock core is tested to find the normal stress corresponding to the Kaiser point.

[0013] The formula for calculating formation pressure is: ; ; ; ; In the formula: —Stress in the overlying strata; , —Maximum and minimum horizontal principal stress; P p —Formation pore pressure; —Effective stress coefficient, which can be taken as 0.8; —Vertical stress at the Kessel point in the core under confining pressure; , , —Kessel point stress under three horizontal core confining pressures at 0°, 45°, and 90°; P c —The confining pressure borne by the rock core inside the high-pressure wellbore; K—Containing pressure correction factor.

[0014] Compared with the prior art, the advantages of the present invention are: This invention provides a device and method for testing the physical and mechanical properties of formation hydrothermal pressurization processes. It can simulate actual formation conditions, analyze the effect of temperature increase on pore pressure using rock cuttings samples under predetermined temperature and pressure, and calculate the elastic modulus, Poisson's ratio, and predict formation pressure. The device is simple to operate, can simulate formation hydrothermal pressurization processes, and provides highly reliable data. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the physical and mechanical properties testing device for the formation hydrothermal pressurization process according to the present invention; Figure 2 A schematic diagram of the cross-sectional structure of the upper or lower plunger; Figure 3 The stress-strain curves tested in Example 1; Figure 4 The stress-strain curves were tested in Example 2.

[0016] In the diagram, 1. Support; 2. Computer system; 3. Acoustic signal probe; 4. Acoustic emission signal processor; 5. Temperature controller; 6. Displacement sensor; 7. Axial pressure loader; 8. Axial pressure controller; 9. Confining pressure controller; 10. Liquid supply and drainage device; 11. Vacuum suction device; 12. Upper core plunger; 13. Lower core plunger; 14. Gas supply and exhaust device; 15. Pore pressure controller; 16. Core holder; 17. Reactor; 18. Plunger; 19. Vent. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments.

[0018] It should be understood that the specific embodiments described herein are only for explaining the present invention, and that the described embodiments are only a part of the embodiments of the present invention, not all of them. Some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual size of the product; for those skilled in the art, some well-known structures and their descriptions in the drawings may be omitted; the terms "upper," "lower," "top," "bottom," "side," "end," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present 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 the present invention.

[0019] Example 1 like Figure 1 As shown, a testing device for the physical and mechanical properties of a formation hydrothermal pressurization process includes a support 1, a computer system 2, an acoustic signal probe 3, an acoustic emission signal processor 4 to collect and process acoustic signals, a temperature controller 5 to control the experimental temperature, an axial pressure loader 7 and an axial pressure controller 8 to control the loading of axial pressure, a confining pressure controller 9 to control the loading of confining pressure, a liquid supply and drainage device 10 connected to it, which controls the pressure through liquid supply and drainage, a displacement sensor 6 to measure the displacement of the rock sample, a core fixer 16, an upper core plunger 12, and a lower core plunger 13 to fix the rock sample, and both the upper core plunger 12 and the lower core plunger 13 have vent holes. Gas is controlled by a pore pressure controller 15 and a gas supply and exhaust device 14 to control the pore pressure. The operation of each component is controlled by the computer system 2.

[0020] The axial pressure controller 8 and confining pressure controller 9 are connected to the liquid supply and discharge device 10. By controlling the confining pressure controller 9, a signal is transmitted to the liquid supply and discharge device 10, and liquid is input along the pipeline. The confining pressure is applied to the core through hydraulic lifting. By controlling the axial pressure controller 8, a signal is transmitted to the liquid supply and discharge device 10. The liquid supply and discharge control axial pressure loader 7 causes the axial pressure loader 7 to rise, while the plunger 18 remains stationary. The reactor 17 is raised, allowing the plunger 18 to penetrate deeper into the reactor cavity, thereby generating axial pressure.

[0021] like Figure 2 As shown, both the upper core plunger 12 and the lower core plunger 13 have vent holes 19 on their cross-sections. These vent holes allow for vacuuming and control of pore pressure. The vent holes can be closed (see attached diagram). Figure 1 The automatic valve is omitted in the text (the position of the automatic valve can be determined as needed to achieve the purpose), thereby realizing the function of sealing the pore pressure.

[0022] Working principle: During the experiment, the actual situation of the core in the formation is simulated by controlling the axial pressure, confining pressure, pore pressure, and temperature of the core. Adjusting the temperature increases the core temperature, simulating the formation hydrothermal pressurization process. As the temperature increases, the core pore pressure rises, the acoustic parameters change, and minute axial and radial displacements occur. The elastic modulus and Poisson's ratio also change. The experimental apparatus is used to test and record the physical and mechanical properties of the formation during the hydrothermal pressurization process.

[0023] This invention also provides a method for testing the physical and mechanical properties of a formation hydrothermal pressurization process, using the aforementioned testing device for the physical and mechanical properties of a formation hydrothermal pressurization process. The method includes the following steps: S1, the diameter of the core holder 16 is connected to the radial and axial displacement sensors 6, and the vent holes 21 on the upper core plunger 12 and the lower core plunger 13 are connected to the pipeline of the vacuum pump 11.

[0024] S2. Install the lower core plunger 13, install an oil-separating sleeve and a thermoplastic tube along the diameter of the core holder 16, then load the rock cutting sample from region A, cover it with the upper core plunger 12, control the axial pressure loader 7 to apply axial pressure, lift the reactor 17 to move upward, and insert the plunger 18 into the inner cavity of the reactor 17 to press the rock cutting sample and compress it into a standard core for experimental use. S3. Vacuum the core sample using vacuum pump 11.

[0025] S4. Simulating actual geological conditions, the axial pressure, confining pressure, and pore pressure of the core sample are applied at predetermined levels using a computer-controlled axial pressure controller 8, confining pressure controller 9, and pore pressure controller 15. The core sample is then controlled to a specified temperature using a temperature controller 5.

[0026] S5. Maintain the axial pressure and confining pressure of the core unchanged, and close the gas inlet and outlet channels of the core sample through the pore pressure controller to achieve the sealing of the core pore pressure.

[0027] S6. Simulate the actual formation hydrothermal pressurization process. Adjust the rock sample temperature using temperature controller 5. Keep the axial and confining pressures of the core constant, and seal the pore pressure. As the temperature increases, the core exhibits changes in the physical and mechanical properties of the hydrothermal pressurization process. Changes occur in the pore pressure, radial and axial deformation, and acoustic parameters of the core sample. Record these changes.

[0028] S7. Analyze the physical and mechanical properties of the formation hydrothermal pressurization process. The increase in temperature affects the pore pressure; study its variation law. Furthermore, based on radial and axial deformation, the elastic modulus and Poisson's ratio can be calculated, and based on changes in acoustic parameters, formation pressure can be predicted.

[0029] In this embodiment, the formula for calculating the elastic modulus is as follows: ; The measured stress-strain curves are as follows Figure 3 As shown, the calculated elastic modulus E is 35.57 GPa.

[0030] Example 2 A method for testing the physical and mechanical properties of a formation hydrothermal pressurization process, using the aforementioned testing device for the physical and mechanical properties of a formation hydrothermal pressurization process, the method comprising the following steps: S1, the diameter of the core holder 16 is connected to the radial and axial displacement sensors 6, and the vent holes 21 on the upper core plunger 12 and the lower core plunger 13 are connected to the pipeline of the vacuum pump 11.

[0031] S2. Install the lower core plunger 13, install an oil-separating sleeve and a thermoplastic tube along the diameter of the core holder 16, then load the rock cutting sample from region B, cover it with the upper core plunger 12, control the axial pressure loader 7 to apply axial pressure, lift the reactor 17 to move upward, and insert the plunger 18 into the inner cavity of the reactor 17 to press the rock cutting sample and compress it into a standard core for experiment. S3. Vacuum the core sample using vacuum pump 11.

[0032] S4. Simulating actual geological conditions, the axial pressure, confining pressure, and pore pressure of the core sample are applied at predetermined levels using a computer-controlled axial pressure controller 8, confining pressure controller 9, and pore pressure controller 15. The core sample is then controlled to a specified temperature using a temperature controller 5.

[0033] S5. Maintain the axial pressure and confining pressure of the core unchanged, and close the gas inlet and outlet channels of the core sample through the pore pressure controller to achieve the sealing of the core pore pressure.

[0034] S6. Simulate the actual formation hydrothermal pressurization process. Adjust the rock sample temperature using temperature controller 5. Keep the axial and confining pressures of the core constant, and seal the pore pressure. As the temperature increases, the core exhibits changes in the physical and mechanical properties of the hydrothermal pressurization process. Changes occur in the pore pressure, radial and axial deformation, and acoustic parameters of the core sample. Record these changes.

[0035] S7. Analyze the physical and mechanical properties of the formation hydrothermal pressurization process. The increase in temperature affects the pore pressure; study its variation law. Furthermore, based on radial and axial deformation, the elastic modulus and Poisson's ratio can be calculated, and based on changes in acoustic parameters, formation pressure can be predicted.

[0036] In this embodiment, the formula for calculating the elastic modulus is as follows: ; The measured stress-strain curves are as follows Figure 4 As shown, the calculated elastic modulus E is 38.86 GPa and the Poisson's ratio is 0.208.

[0037] The formula for calculating Poisson's ratio in rocks is: ; Other areas not mentioned are the same as in Example 1.

[0038] Example 3 The rock cuttings samples were selected from rock cuttings samples from region C. According to the formula for calculating formation pressure, the measured vertical Kessel point was 67.89 MPa, the 0° Kessel point was 69.42 MPa, the 45° Kessel point was 69.93 MPa, and the 90° Kessel point was 63.82 MPa. The calculated overlying strata pressure was 67.89 MPa, the maximum horizontal stress was 70.96 MPa, and the minimum horizontal stress was 62.28 MPa.

[0039] Other areas not mentioned are the same as in Example 1.

[0040] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.

[0041] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A testing device for the physical and mechanical properties of formation hydrothermal pressurization processes, comprising a support, a computer system, and a core holder, wherein the support is provided with a base and a top cover, and a downwardly extending main body is provided in the center of the top cover, characterized in that, The testing device also includes an acoustic emission signal processing unit, a displacement sensor, an axial pressure loader, a liquid supply and discharge device, a gas supply and exhaust device, a temperature controller, a confining pressure controller, a pore pressure controller, and a reaction vessel; The axial pressure loader is installed on the platform at the bottom of the support, and the reaction vessel is installed on the axial pressure loader; the reaction vessel is a solid shell, and a plunger is installed in the opening at the center of the top of the shell. The interior is a hollow cavity, and the plunger is vertically installed below the top cover of the support by a fixing component. The axial pressure loader and the outer shell of the reactor are both connected to the liquid supply and discharge device, the axial pressure controller, and the confining pressure controller via pipelines; an acoustic signal probe and a temperature controller probe are installed on the inner wall of the reactor. The acoustic signal probe is connected to the acoustic emission signal processor via a pipeline, and the temperature controller probe is connected to the temperature controller via a pipeline. The inner cavity of the reactor is equipped with a core holder capable of pressing rock fragments into core samples. The inner cavity is also provided with pipelines that connect to a vacuum pump and in parallel to a gas supply and exhaust device, a pore pressure controller, and radial and axial displacement sensors. The core holder includes an upper core plunger, a pipe diameter, and a lower core plunger. The connection ends of the radial and axial displacement sensor pipelines are installed on the pipe diameter. A vent hole is provided in the center of both the upper and lower plungers. The vent hole connects to the vacuum pump and in parallel to the gas supply and exhaust device and the pore pressure controller. The reactor, acoustic emission signal processing unit, displacement sensor, axial pressure loader, liquid supply and discharge device, gas supply and exhaust device, temperature controller, confining pressure controller, and pore pressure controller are all connected to the computer system.

2. The testing device for the physical and mechanical properties of formation hydrothermal pressurization process according to claim 1, characterized in that, The reactor is sealed at the contact point with the plunger, and sealing rings are installed at the connection points between each pipeline and the shell.

3. The testing device for the physical and mechanical properties of formation hydrothermal pressurization process according to claim 1, characterized in that, An automatic valve is installed on the pipeline connecting to the vent, and the computer system is able to control the vent to close in order to seal the pore pressure.

4. A method for testing the physical and mechanical properties of a formation hydrothermal pressurization process, using the testing device for the physical and mechanical properties of a formation hydrothermal pressurization process as described in any one of claims 1 to 3, characterized in that, The method includes the following steps: S1. The pipe diameter of the core holder is connected to the radial and axial displacement sensors, and the vent holes on the upper and lower core plungers are connected to the pipelines of the vacuum pump. S2. Install the lower core plunger, install an oil-separating sleeve and a thermoplastic tube along the diameter of the core holder, then load the rock cutting sample, cover it with the upper core plunger, control the axial pressure loader to apply axial pressure, lift the reactor upward, and insert the plunger into the inner cavity of the reactor to press the rock cutting sample and compress it into a core sample. S3. Vacuum the core sample using a vacuum pump; S4. Apply a predetermined amount of axial pressure, confining pressure, and pore pressure to the core sample using a computer-controlled axial pressure loader, confining pressure controller, and pore pressure controller; control the core sample to a specified temperature using a temperature controller; S5. Maintain axial pressure and confining pressure constant, and close the gas inlet and outlet channels of the core sample through the pore pressure controller to achieve pore pressure closure; S6. Adjust the rock sample temperature using a temperature controller. As the temperature rises, the pore pressure, radial and axial deformation, and acoustic parameters of the rock sample change. Record the changes in the data. S7. Analyze the effect of temperature rise on pore pressure, and further calculate the elastic modulus and Poisson's ratio based on radial and axial deformation; predict formation pressure based on changes in acoustic parameters.

5. The method for testing the physical and mechanical properties of a formation hydrothermal pressurization process according to claim 4, characterized in that, In step S6, the temperature of the reactor is increased by the temperature controller, and the pore pressure of the core sample increases accordingly. The values ​​of axial stress increment and axial strain increment can be obtained by the radial and axial displacement sensors, and the elastic modulus can be calculated.

6. The method for testing the physical and mechanical properties of a formation hydrothermal pressurization process according to claim 4, characterized in that, In step S6, the temperature of the reactor is increased by a temperature controller, and the pore pressure of the core sample increases accordingly. The values ​​of axial strain increment and radial strain increment can be obtained by radial and axial displacement sensors, and the Poisson's ratio of the rock can be calculated.

7. The method for testing the physical and mechanical properties of a formation hydrothermal pressurization process according to claim 4, characterized in that, In step S6, the confining pressure and pore pressure borne by the core sample are measured, and the acoustic emission curve of each core sample is tested to find the normal stress corresponding to the Kaiser point in order to calculate the formation pressure.

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