A high temperature and high pressure filter cake bed filtration loss device and method of use

Abstract

This invention discloses a high-temperature, high-pressure filter cake layer filtration device and its usage method, relating to the field of drilling fluid performance testing technology. The device includes a wellbore, a fixing mechanism, and a storage mechanism; the wellbore is installed on the fixing mechanism, and the storage mechanism is located below the wellbore; a piston mechanism is installed on the wellbore. The method includes preparing a rock sample from a core of the target rock formation; embedding the rock sample into the wellbore and pushing it to the bottom; fixing the wellbore to the fixing mechanism; placing a heating mechanism; pouring drilling fluid into the wellbore; attaching a pressure sensor to the piston block and connecting it to a pressure gauge; pulling the piston block to the top; placing a camera at the core directly opposite the front end of the wellbore; starting the heating mechanism; closing the pressure relief valve and opening the valve; continuously pressurizing; turning off the high-speed camera, valve, and motor; opening the pressure relief valve and unscrewing the piston block; turning off the heating mechanism; removing the filtrate; extracting parameters; and removing the filter cake. This invention can achieve the purpose of rapidly obtaining rock formation filter cake experimental samples and drilling fluid filtrate.

Description

Technical Field

[0001] This invention relates to the field of drilling fluid performance testing technology, specifically to a high-temperature and high-pressure filter cake layer filtration device and its usage method. Background Technology

[0002] Deep rock formations are subjected to high temperature and high pressure environments for extended periods. During drilling, the mechanochemical reactions caused by drilling fluid intrusion lead to a decrease in rock strength, resulting in wellbore instability, spalling, and even collapse. Therefore, experimentally discussing the mechanical strength of the rock filter cake and the physicochemical properties of the filtrate during drilling is one of the important methods for studying the influence of drilling fluid on rock strength and wellbore stability. Furthermore, drilling fluid is the "blood" of drilling operations, and its filtrate loss and filter cake quality are crucial indicators for judging the performance of drilling fluid.

[0003] Currently, the commonly used methods for obtaining drilling fluid filtrate volume are: manual high-temperature and high-pressure filtrate analyzers and API filtrate analyzers. These instruments are expensive, the filtrate acquisition process is cumbersome, and they cannot obtain rock filter cake test samples in a targeted manner.

[0004] Therefore, it is necessary to design a high-temperature and high-pressure filter cake layer filtration device to solve the existing problems. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing a high-temperature and high-pressure filter cake layer filtration device and its usage method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-temperature and high-pressure filter cake layer filtration device is characterized by comprising a well shaft, a fixing mechanism, and a storage mechanism; the well shaft is mounted on the fixing mechanism, and the storage mechanism is located below the well shaft; a piston mechanism is also mounted on the well shaft; the piston mechanism includes a piston push rod, a piston jaw, a piston connecting rod, and a piston block; a motor is installed inside the piston push rod, and the motor is electrically connected to an external power source; the upper end of the piston connecting rod is connected to the output end of the motor, and the lower end of the piston connecting rod passes through the piston jaw and is connected to the piston block; a rock sample is installed inside the well shaft, and the piston block is movably positioned between the piston jaw and the rock sample; the rock sample is located at the bottom of the well shaft, and a heating mechanism is provided above the rock sample, the heating mechanism being connected to an external power source.

[0008] Based on the above technical solution, further, the top of the well shaft is provided with a first opening and the bottom of the well shaft is provided with a second opening. The cross-sectional area of ​​the first opening is larger than the cross-sectional area of ​​the second opening, and a valve is provided on the second opening.

[0009] Based on the above technical solution, further, the piston bayonet is located at the first opening position, and a threaded hole structure is provided at the middle position of the piston bayonet, and the lower end of the piston connecting rod passes through the threaded hole of the piston bayonet and connects with the piston block.

[0010] Based on the above technical solution, further, the piston jaw is a rubber sheet with a diameter of 51mm, and the diameter of the threaded hole in the middle of the piston jaw is 15mm.

[0011] Based on the above technical solution, furthermore, a thermometer and a pressure sensor are provided at the bottom of the piston block, wherein the pressure sensor is connected to an external pressure gauge signal.

[0012] Based on the above technical solution, at least one pressure relief valve is further provided through the piston block.

[0013] Based on the above technical solution, the piston block is further described as a 51mm diameter rubber circular piston with a pressure resistance range of 0-150MPa.

[0014] Based on the above technical solution, the piston connecting rod is further described as a metal threaded rod with a diameter of 15mm and a pressure resistance range of 0-150MPa.

[0015] Based on the above technical solution, furthermore, at least one sealing ring is provided at the top and bottom of the rock sample, with an inner diameter of 45mm, an outer diameter of 51mm, and a thickness of 2mm.

[0016] Based on the above technical solution, the heating mechanism is further described as an electric heating rod, which is fixed at the rear end of the top sealing ring and has a heating range of 0-120℃.

[0017] Based on the above technical solution, a cover is further provided, and the well shaft, fixing mechanism and storage mechanism are all located inside the cover.

[0018] Based on the above technical solution, a camera mechanism is further provided, which is located outside the cover and the output end of the camera mechanism faces the well shaft.

[0019] Furthermore, based on the above technical solution, the cover is a transparent dustproof cover.

[0020] Based on the above technical solution, the storage mechanism further includes a beaker and a filter paper pad, with the beaker located below the well shaft and the filter paper pad located on top of the beaker.

[0021] A method for using a high-temperature, high-pressure filter cake layer filtration device includes the following steps: Step 1: Prepare a rock sample from the target rock core and sandwich it between two sealing rings; Step 2: Embed the rock sample into the top of the wellbore and push it to the bottom of the wellbore; Step 3: Fix the wellbore to the fixing mechanism, keeping the wellbore perpendicular to the horizontal plane; Step 4: Place the heating mechanism in the wellbore and connect the thermometer and power supply; Step 5: Pour 100-150ml of drilling fluid to be studied into the wellbore; Step 6: Attach the pressure sensor to the front end of the piston block and connect it to the pressure gauge outside the cover; Step 7: Engage the piston jaws at the first opening, pull the piston block to the top by rotating the piston push rod, connect the motor in the piston push rod to the piston connecting rod, and connect the motor to the power supply; Step 8: Set the storage mechanism in the center of the wellbore. Below, cover the casing and place the camera mechanism at the core directly opposite the front end of the wellbore; Step 9: Start the heating mechanism to heat the drilling fluid in the wellbore to the specified temperature; Step 10: Close the pressure relief valve, start the motor to pressurize the piston mechanism to the specified pressure, and open the valve; Step 11: Reduce the motor power and continue to pressurize to maintain the specified pressure; Step 12: When the filtrate dripping rate decreases and the core color no longer changes, turn off the camera mechanism, close the valve and motor, open the pressure relief valve, and unscrew the piston block; Step 13: Turn off the heating mechanism; Step 14: Remove the filter paper pad and the filtrate in the beaker for subsequent experiments or tests; Step 15: Extract the parameters of the core filter cake being wetted by the drilling fluid and the filter cake thickness change recorded by the camera mechanism; Remove the filter cake for subsequent experiments and evaluation.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) This invention can produce filter cake and filtrate after drilling fluid is immersed in rock formation under high temperature and high pressure, providing materials for experimental research on well wall stability under high temperature, high pressure and multiple field influences; and it uses transparent, high-strength and high-transparency materials, which can be observed directly by visual observation or further studied by high-speed camera equipment; the materials and accessories are simple, low-cost and easy to operate, and can be produced and applied in the field laboratory.

[0024] (2) This invention is mainly used for testing the influence of drilling fluid on the mechanical properties of wellbore rock formations at drilling sites or in laboratories. It can achieve the purpose of quickly, conveniently, and visually obtaining rock filter cake test samples and drilling fluid filtrate, and has obvious good application and promotion prospects. In addition, although this design is aimed at the petroleum field, it can also be applied to other fields, such as: permeability determination of porous materials under the influence of multiple factors, preparation of porous materials multi-field coupling test specimens, geotechnical permeability tests, etc. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0026] Figure label:

[0027] 1. Cover; 2. Fixing mechanism; 3. Well shaft; 4. Valve; 5. Pressure relief valve; 6. Pressure sensor; 7. Pressure gauge; 8. Rock sample; 9. Power supply; 10. Heating mechanism; 11. Piston push rod; 12. Piston bayonet; 13. Piston connecting rod; 14. Piston block; 15. Beaker; 16. Filter paper gasket. Detailed Implementation

[0028] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in the various embodiments of the present invention can be combined accordingly without mutual conflict.

[0030] In the description of this invention, it should be understood that when an element is considered to be "connected" to another element, it can be a direct connection to the other element or an indirect connection, i.e., there is an intermediate element. Conversely, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0031] In the description of this invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features.

[0032] Example 1

[0033] Combination Figure 1As shown, this embodiment provides a high-temperature and high-pressure filter cake layer filtration device, which includes a cover 1, a fixing mechanism 2, a well cylinder 3, and a storage mechanism. The cover 1 is a transparent dustproof cover. The fixing mechanism 2, the well cylinder 3, and the storage mechanism are all located inside the cover 1. The storage mechanism is located below the bottom of the well cylinder 3, and preferably, the storage mechanism, the fixing mechanism 2, and the bottom of the cover 1 are on the same horizontal plane. Furthermore, one end of the fixing mechanism 2 is vertically fixed to the ground, and the other end of the fixing mechanism 2 fixes the well cylinder 3. Specifically, the fixing mechanism 2 can be a fixing frame structure, and a fixing ring can be provided at the other end of the fixing mechanism 2. The well cylinder 3 is fitted inside the fixing ring to achieve suspension and fixation, and the well cylinder 3 is arranged parallel to the fixing mechanism 2. In some embodiments, the well barrel 3 is a simulated well barrel with a syringe structure. The top of the well barrel 3 has a first opening and the bottom has a second opening. The first opening is a wide opening and the second opening is a narrow opening, that is, the cross-sectional area of ​​the first opening is larger than the cross-sectional area of ​​the second opening. A valve 4 is provided on the second opening to control the output flow rate of the sample to be tested inside the well barrel 3. The simulated well barrel is made of high-transparency and high-strength glass. The inner diameter of the simulated well barrel is about 51 mm and the length is 150 mm. The pressure resistance range of the inner wall is 0-150 MPa and the temperature range is 10℃-150℃.

[0034] In this embodiment, a piston mechanism is also installed on the wellbore 3. Specifically, the piston mechanism is movably installed on the wellbore 3 through a first opening and is used to pressurize the inside of the wellbore 3. The piston mechanism includes a piston push rod 11, a piston bayonet 12, a piston connecting rod 13, and a piston block 14. The piston push rod 11 houses a motor, which is electrically connected to an external power supply 9. The start and stop of the motor are controlled by controlling the power supply 9 switch. The upper end of the piston connecting rod 13 is connected to the output end of the motor, and the lower end of the piston connecting rod 13 passes through the threaded hole of the piston bayonet 12 and connects to the piston block 14. A thermometer and a pressure sensor 6 are located at the bottom of the piston block 14, and at least one pressure relief valve 5 is also installed through the piston block 14. The pressure sensor 6 and the external pressure gauge 7 can be connected wirelessly or via a wired connection. The thermometer monitors the temperature inside the wellbore 3 and transmits the monitored signal to an external terminal device, which can be a computer or a data acquisition device, etc. Figure 1To achieve a wired connection, one end of the signal line passes through the piston block 14 and connects to the pressure sensor 6 at its bottom, while the other end connects to the pressure gauge 7. It should be noted that this signal line does not affect the movement of the entire piston mechanism. Furthermore, the piston bayonet 12 is located at the first opening position, and a threaded hole structure is provided in the middle of the piston bayonet 12. The piston connecting rod 13 has an external threaded structure. Driven by the motor, the threads of the piston connecting rod 13 engage with the threaded hole of the piston bayonet 12, enabling vertical movement within the wellbore 3. It should be noted that the piston bayonet 12 is a rubber sheet with a diameter of 51mm and a thickness of 10mm, mainly used to fix the piston mechanism inside the well shaft 3. The piston bayonet 12 has a threaded hole with a diameter of 15mm in the middle. The piston connecting rod 13 is a metal threaded rod structure with a diameter of 15mm and a pressure resistance range of 0-150MPa. The piston connecting rod 13 passes through the threaded hole in the middle of the piston bayonet 12 and connects to the piston block 14. The piston block 14 is a rubber circular piston with a diameter of 51mm and a pressure resistance range of 0-150MPa.

[0035] In this embodiment, a rock sample 8 is installed inside the wellbore 3. A piston block 14 is movably disposed between the piston bayonet 12 and the rock sample 8. The rock sample 8 is located at the bottom of the wellbore 3. At least one sealing ring is provided at the top and bottom of the rock sample 8. The sealing ring has an inner diameter of 45mm, an outer diameter of 51mm, and a thickness of 2mm.

[0036] In this embodiment, a heating mechanism 10 is provided above the rock sample 8. This heating mechanism 10 is an electric heating rod, which is fixed to the rear end of the top sealing ring and has a heating range of 0-120℃. The heating rod can be connected to an external power supply 9 via a wired connection, and the heating effect is achieved through the control of the power supply 9.

[0037] In this embodiment, a camera mechanism can also be provided. The camera mechanism is located outside the cover 1, and the output end of the camera mechanism faces the simulated wellbore. Specifically, the camera mechanism includes a high-speed camera, and the output end of the high-speed camera faces the center of the rock sample 8.

[0038] In this embodiment, the storage mechanism includes a beaker 15 and a filter paper pad 16. The beaker 15 is disposed below the simulated well shaft, and the filter paper pad 16 is disposed on top of the beaker 15.

[0039] This device can produce filter cake and filtrate after drilling fluid has penetrated into rock formations under high temperature and high pressure, providing materials for experimental research on wellbore stability under high temperature, high pressure and multiple field influences; it uses transparent, high-strength and high-transparency materials, which can be observed directly by sight or further studied by high-speed camera equipment; the materials and accessories are simple, low-cost, and easy to operate, and can be manufactured and applied in the field laboratory.

[0040] Example 2

[0041] Based on the apparatus of Example 1, a method for using a high-temperature and high-pressure filter cake layer filtration device includes the following steps:

[0042] Step 1: Prepare a rock sample 8 from the target rock core, 50mm in diameter and 20-50mm in height, and insert it between two sealing rings. Step 2: Embed the rock sample 8 from Step 1 into the top of the wellbore 3 and push it to the bottom of the wellbore 3. Step 3: Fix the wellbore 3 to the fixing mechanism 2, ensuring the wellbore 3 is perpendicular to the horizontal plane. Step 4: Place the heating mechanism 10 and connect the thermometer and power supply 9; Step 5: Pour 100-150ml of the drilling fluid to be studied into the wellbore 3; Step 6: Attach the pressure sensor 6 to the front end of the piston block 14 and connect it to the pressure gauge 7 outside the cover 1; Step 7: Engage the piston latch 12 at the first opening, pull the piston block 14 to the top by rotating the piston push rod 11, connect the motor in the piston push rod 11 to the piston connecting rod 13, and connect the motor to the power supply 9; Step 8: Place the storage mechanism directly below the wellbore 3, cover the cover 1, and place the high-speed camera at the core position directly opposite the front end of the wellbore 3; Step 9: Activate the heating mechanism 10 to heat the drilling fluid inside the wellbore 3. Step 10: Close the pressure relief valve 5, start the motor to pressurize the piston mechanism to the specified pressure, and open the valve 4; Step 11: Reduce the power of the motor and continue to pressurize to maintain the specified pressure; Step 12: When the dripping speed of the filtrate decreases significantly and the color of the core no longer changes, turn off the high-speed camera, close the valve 4 and the motor, open the pressure relief valve 5, and unscrew the piston block 14; Step 13: Turn off the heating mechanism 10; Step 14: Take out the filter paper pad 16 and the filtrate in the beaker 15 for subsequent experiments or tests; Step 15: Extract the parameters of the various processes of the core filter cake being wetted by the drilling fluid and the change in filter cake thickness recorded by the high-speed camera; Take out the filter cake for subsequent experiments and evaluation.

[0043] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A high-temperature, high-pressure filter cake layer filtration device, characterized in that, Includes well casing, fixing mechanism, and storage mechanism; The well casing is mounted on a fixed mechanism, and the storage mechanism is located below the well casing. A piston mechanism is also installed on the wellbore; the piston mechanism includes a piston push rod, a piston bayonet, a piston connecting rod, and a piston block; the piston push rod has a motor inside, and the motor is electrically connected to an external power source; the upper end of the piston connecting rod is connected to the output end of the motor, and the lower end of the piston connecting rod passes through the piston bayonet and is connected to the piston block. A rock sample is placed inside the wellbore. A piston block is movable between the piston jaw and the rock sample. The rock sample is located at the bottom of the wellbore, and a heating mechanism is provided above the rock sample. The heating mechanism is connected to an external power source.

2. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, The top of the well shaft is provided with a first opening, and the bottom of the well shaft is provided with a second opening. The cross-sectional area of ​​the first opening is larger than that of the second opening, and a valve is provided on the second opening. The piston bayonet is located at the first opening position, and a threaded hole structure is provided in the middle of the piston bayonet. The lower end of the piston connecting rod passes through the threaded hole of the piston bayonet and connects with the piston block.

3. The high-temperature and high-pressure filter cake layer filtration device according to claim 2, characterized in that, The piston jaw is a rubber sheet with a diameter of 51mm, and the threaded hole in the middle of the piston jaw has a diameter of 15mm.

4. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, The bottom of the piston block is equipped with a thermometer and a pressure sensor, wherein the pressure sensor is connected to an external pressure gauge.

5. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, At least one pressure relief valve is also provided through the piston block.

6. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, The rock sample is provided with at least one sealing ring at the top and bottom respectively. The heating mechanism is an electric heating rod, which is fixed at the rear end of the top sealing ring and has a heating range of 0-120℃.

7. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, It also includes a cover and a camera mechanism. The well shaft, fixing mechanism and storage mechanism are all located inside the cover; the camera mechanism is located outside the cover, and the output end of the camera mechanism faces the well shaft.

8. The high-temperature and high-pressure filter cake layer filtration device according to claim 7, characterized in that, The cover is a transparent dustproof cover.

9. The high-temperature and high-pressure filter cake layer filtration device according to claim 1, characterized in that, The storage mechanism includes a beaker and a filter paper pad, with the beaker positioned below the well shaft and the filter paper pad positioned above the beaker.

10. A method of using a high-temperature and high-pressure filter cake layer filtration device, characterized in that, The high-temperature and high-pressure filter cake layer filtration device according to any one of claims 1-9 is used in a method comprising the following steps: Step 1: Prepare a rock sample from the core of the target rock layer and sandwich it between two sealing rings; Step 2: Insert the rock sample into the top of the well casing and push the rock sample to the bottom of the well casing; Step 3: Secure the well casing to the fixing mechanism, keeping the well casing perpendicular to the horizontal plane; Step 4: Place the heating element in the container and connect the thermometer and power supply; Step 5: Pour 100-150ml of the drilling fluid to be studied into the wellbore; Step 6: Attach the pressure sensor to the front end of the piston block and connect it to the pressure gauge outside the casing; Step 7: Engage the piston bayonet at the first opening, pull the piston block to the top by rotating the piston push rod, connect the motor in the piston push rod to the piston connecting rod, and connect the motor to the power supply; Step 8: Place the storage mechanism directly below the wellbore, cover it, and place the camera mechanism at the core of the wellbore directly in front of the wellbore. Step 9: Activate the heating mechanism to heat the drilling fluid in the wellbore to the specified temperature; Step 10: Close the pressure relief valve, start the motor to pressurize the piston mechanism to the specified pressure, and then open the valve; Step 11: Reduce the motor power while maintaining the specified pressure; Step 12: When the dripping rate of the filtrate decreases and the color of the core no longer changes, turn off the camera mechanism, shut off the valve and motor, open the pressure relief valve, and unscrew the piston block; Step 13: Turn off the heating mechanism; Step 14: Remove the filter paper pad and the filtrate from the beaker for subsequent experiments or tests; Step 15: Extract the parameters of the core filter cake being wetted by drilling fluid and the filter cake thickness change recorded by the camera mechanism; remove the filter cake for subsequent experiments and evaluation.

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