A microprocessor-controlled hydraulic fracturing ground stress measurement device and measurement method

Abstract

The invention discloses a microprocessor-controlled hydraulic fracturing ground stress measuring device, comprising a hydraulic fracturing component, a camera and a microprocessor, wherein the hydraulic fracturing component comprises: a metal pipe, a high-pressure water pipe is arranged at the center of the metal pipe, the water inlet end of the high-pressure water pipe is connected to a ground pressurizing device, a sandwich is formed between the high-pressure water pipe and the metal pipe, a water outlet channel is arranged on the side walls of the high-pressure water pipe and the metal pipe, and a first pressure sensor for detecting water pressure is also arranged in the high-pressure water pipe; a plurality of cameras are arranged on the side wall of the metal pipe through a rotating component, the plurality of cameras are arranged in sequence along the axial direction of the metal pipe, an orienter is also arranged at the lower end of the sandwich, and the rotation angle and orientation of the camera are determined by the orienter; the invention also discloses a microprocessor-controlled hydraulic fracturing ground stress measuring method; the measuring device disclosed in the invention saves the time of lifting and lowering the impression device when measuring each measuring section in the traditional measuring process and improves the success rate, and can save more time as the measuring sections increase.

Description

Technical Field

[0001] The invention belongs to the technical field of geomechanics, and in particular relates to a microprocessor-controlled hydraulic fracturing ground stress measuring device and a measuring method. Background Art

[0002] Hydraulic fracturing is widely used to measure in-situ stress, especially in tunnels, underground engineering and other fields. In addition, hydraulic fracturing is also used in the process of oil and natural gas engineering to increase cracks to form more oil and gas channels. The basic principle of hydraulic fracturing to measure in-situ stress is to use the liquid (water) injected into the closed section of the underground rock formation to pressurize the cracks, and to re-open the cracks several times. When the fractures are stable, the impression is made. The surface of the impression device is coated with soft glue and has a directional device. The orientation of the crack can be determined by the directional device. After the impression device is positioned to the depth of the rock crack, a certain amount of pressure is applied to the impression device to make it expand. After the impression device is close to the hole wall and the pressure is maintained for a certain period of time, the surface soft glue squeezes into the fracture and solidifies. After the soft glue solidifies, the pressure is released and the impression device is taken out. The shape of the impression on the rubber cylinder surface can be sketched on the ground in time to determine the direction of the maximum principal stress according to the orientation of the solidified soft glue.

[0003] When the existing hydraulic fracturing ground stress measurement device determines the direction of the crack in the isolation section, it is necessary to lower the stamper to the measuring section, and pressurize and expand the stamper so that its surface coating is squeezed into the cracks generated during the fracturing process. The pressure is maintained for a certain time to ensure that the coating is solidified and then the pressure is released. After the stamper is lifted, the extension direction of the fracture is obtained based on the direction recorded by the directional device at the lower end of the stamper during the pressurized stamping period and the fracture trace recorded by the surface coating of the stamper. This direction is the maximum horizontal principal stress direction of the measuring section.

[0004] In the existing hydraulic fracturing in-situ stress measurement equipment, fracturing and fracture direction determination are two independent processes. The fracture direction determination of each measuring section in a single borehole requires an independent lowering, measuring and lifting process. Take a single borehole with 5 measuring sections as an example: the fracture direction measurement process of each measuring section takes 1 hour to lower the equipment, 0.5 hours to maintain the pressure mold, and 1 hour to lift the equipment, which takes an average of more than 2.5 hours. The fracture direction measurement time for a single borehole alone exceeds 12 hours, and the entire single-hole in-situ stress measurement process exceeds 24 hours. Because the entire measurement process must be carried out continuously, on-site technicians are extremely tired and engineering accidents are prone to occur, making it difficult to ensure the measurement quality. Summary of the invention

[0005] The purpose of the present invention is to provide a microprocessor-controlled hydraulic fracturing ground stress measuring device, which can solve the problem of long measuring time in the existing hydraulic fracturing ground stress measuring device.

[0006] The technical solution adopted by the present invention is a microprocessor-controlled hydraulic fracturing ground stress measuring device, comprising a hydraulic fracturing assembly, the hydraulic fracturing assembly comprising: a metal pipe, a high-pressure water pipe is arranged at the center of the metal pipe, the water inlet end of the high-pressure water pipe is connected to a ground pressurizing device, a sandwich is formed between the high-pressure water pipe and the metal pipe, a water outlet channel is arranged on the side walls of the high-pressure water pipe and the metal pipe, a first pressure sensor for detecting water pressure is also arranged in the high-pressure water pipe, and the characteristics include:

[0007] A plurality of cameras are provided, and the plurality of cameras are arranged in sequence along the axial direction of the metal pipe. The plurality of cameras are rotatably arranged on the outer wall of the metal pipe through a rotating assembly, and the rotating assembly drives the cameras to rotate around the metal pipe as the center, and the cameras record the process of cracks on the metal pipe when rotating;

[0008] The orienter is arranged at the lower end of the interlayer, and is fixedly connected to a camera at the lower side, and the rotation angle and orientation of the camera are determined by the orienter;

[0009] The microprocessor is arranged in the interlayer, and the camera, the rotating assembly and the director are all connected to the microprocessor.

[0010] The rotating assembly includes a motor arranged on the outer wall of the metal tube, the output shaft of the motor is parallel to the metal tube, a first gear is arranged on the output shaft of the motor, a second gear meshing with the first gear is sleeved on the outer side of the metal tube, the camera is arranged on the second gear, and the motor is connected to the microprocessor.

[0011] The director is arranged at the lower end of the interlayer, and a mounting platform is also arranged at the lower end of the interlayer. The mounting platform is rotatably connected to the outer wall of the high-pressure water pipe, the director is fixedly connected to the upper end of the mounting platform, and a connecting piece is arranged between the lower end of the mounting platform and a second gear at the lowermost side, and the two ends of the connecting piece are respectively fixedly connected to the second gear and the lower end surface of the mounting platform.

[0012] There are three cameras, which are evenly distributed along the circumference of the metal tube.

[0013] A flocculant chamber for storing a flocculant layer is provided at one end of the interlayer close to the ground pressure device, and a feed port and a discharge port for adding and releasing flocculants are provided on the side wall of the metal tube. The feed port is provided on the upper side of the discharge port, and a pushing component for squeezing the flocculant out of the discharge port is also provided in the flocculant chamber.

[0014] The push assembly comprises an electronic push rod arranged on the outer wall of the high-pressure water pipe, a push plate is also arranged at the end of the electronic push rod, the push plate is slidably connected with the upper and lower side walls of the flocculant chamber, and the push rod is connected with the microprocessor.

[0015] The camera has a frame rate of 60-120, a resolution of 720p-1080p, and a waterproof rating of IP68.

[0016] Another technical solution adopted by the present invention is: a method for measuring hydraulic fracturing ground stress controlled by a microprocessor, based on the above hydraulic fracturing ground stress measuring device controlled by a microprocessor, characterized in that it specifically includes the following steps:

[0017] Step 1, sequentially connect the hollow drill pipe, the first packer, the ground stress measuring device, and the second packer, set a second pressure sensor on the side of the first packer close to the drill pipe, connect the second pressure sensor to the microprocessor, and connect the drill pipe to the ground pressurizing device at the same time, and then release the connected whole into the selected measuring section, while keeping all components in a closed state;

[0018] Step 2: Start the ground pressurizing device to set the seal, and after the setting is completed, perform flocculation. After the flocculation is completed, the camera is controlled by the microprocessor to start rotating;

[0019] Step 3: Perform fracturing. After fracturing, turn off the camera and the ground pressure device, and release the pressure through the ground pressure device. After the pressure release is completed, move the connected whole to the next measuring section, and repeat step 2 to measure the next measuring section.

[0020] Step 4: Lift up the first packer, the geostress measuring device and the second packer, and export the data recorded in the microprocessor.

[0021] Step 5: Data processing to calculate the magnitude and direction of ground stress.

[0022] The beneficial effects of the present invention are:

[0023] The present invention discloses a microprocessor-controlled hydraulic fracturing ground stress measuring device, which injects a high-pressure water source into the high-pressure water pipe through a ground pressurizing device connected to the high-pressure water pipe, and then the high-pressure water flows into the outside of the metal pipe through the water outlet channel to form high pressure in the isolation section, and finally the rotating component drives the camera to rotate to record the process of crack generation on the metal pipe, and at the same time, the angle and direction of the camera rotation can be determined by the orientator during the crack observation process. Therefore, the present invention realizes the integration of the fracturing process and the crack direction determination process into a unified process, and records the image of the crack formation process and the crack direction during fracturing. The pressure data of the fracturing process, the image data of the crack formation process, and the direction data after the crack is formed are all obtained by the microprocessor. The processor controls and stores the data in the memory card. After all the measuring sections have completed the test, the system is lifted to the ground uniformly, and the data in the memory card is read to determine the magnitude and direction of the ground stress. Compared with the traditional hydraulic fracturing method, the ground stress measuring device disclosed in the invention can save the time of lifting the stamp back and forth when measuring; the traditional hydraulic fracturing method and the device both perform fracturing in the measuring section and observe the direction of the crack, but the measuring device disclosed in the present invention saves the time of lifting and lowering the stamp when measuring each measuring section in the traditional measurement process. As the number of measuring sections increases, the device can save more time than the traditional process. The measuring device disclosed in the present invention can complete the determination of the direction of the single-hole crack and the magnitude of the principal stress in 12 hours or even less. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of a microprocessor-controlled hydraulic fracturing ground stress measuring device of the present invention;

[0025] Figure 2 It is a rear view of a microprocessor-controlled hydraulic fracturing ground stress measuring device of the present invention;

[0026] Figure 3 It is a top view of a microprocessor-controlled hydraulic fracturing ground stress measuring device of the present invention.

[0027] In the figure, 1. metal tube, 2. flocculant chamber, 3. camera, 4. water outlet channel, 5. high-pressure water pipe, 6. feed port, 7. discharge port, 8. microprocessor, 9. rechargeable battery, 10. director. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection solution of the present invention.

[0029] The present invention discloses a microprocessor-controlled hydraulic fracturing ground stress measuring device, comprising a hydraulic fracturing component, a camera 3 and a microprocessor 8, wherein the hydraulic fracturing component comprises: a metal tube 1, a high-pressure water pipe 5 is arranged at the center of the metal tube 1, the water inlet end of the high-pressure water pipe 5 is connected to a ground pressurizing device, a sandwich is formed between the high-pressure water pipe 5 and the metal tube 1, a water outlet channel 4 is arranged on the side wall of the high-pressure water pipe 5 and the metal tube 1, and a first pressure sensor for detecting water pressure is also arranged in the high-pressure water pipe 5; a plurality of cameras 3 are arranged, and a rechargeable battery 9 connected to the plurality of cameras 3 for providing power to the cameras is also arranged in the sandwich, and the plurality of cameras 3 are all arranged on the outer wall of the metal tube 1, and the cameras 3 are all arranged on the metal tube 1 through a rotating component. On the metal tube 1, the camera 3 can be driven to rotate around the metal tube 1 through a rotating assembly, and multiple cameras 3 are arranged in sequence along the axial direction of the metal tube 1; an orienter 10 is provided at the lower end of the interlayer, and the orienter 10 is fixedly connected to a camera at the lower end, and the rotation angle and direction of the camera 3 can be determined by the orienter 10; the camera can record the process of crack generation on the metal tube when rotating, and during the crack observation process, the orienter 10 maintains a fixed angle with multiple numbered cameras, and the multiple cameras also maintain a fixed angle. As the monitoring process begins, the multiple cameras rotate at a fixed rate, and the direction of the orienter 10 remains unchanged. The direction of the crack is determined by the data recorded by the microprocessor 8 and the direction of the orienter 10.

[0030] In order to ensure that the camera 3 can rotate around the metal tube 1, the rotating assembly disclosed in this embodiment includes a motor arranged on the outer wall of the metal tube 1, the output shaft of the motor is parallel to the metal tube 1, a first gear is arranged on the output shaft of the motor, a second gear meshing with the first gear is sleeved on the outer side of the metal tube 1, the camera 3 is arranged on the second gear, and the motor is connected to the microprocessor 8. When the microprocessor 8 controls the motor to rotate, the motor drives the second gear sleeved on the metal tube 1 to rotate with the high-pressure water pipe as the axis through the first gear, so when the second gear rotates, the camera arranged on the end face of the second gear also rotates with the metal tube 1 as the axis; in order to ensure that each rotating assembly can work normally, a cover is arranged on the outer side of the rotating assembly.

[0031] At the same time, in order to enable the orientator 10 to rotate synchronously with the camera 3, the orientator 10 disclosed in this embodiment is arranged at the lower end of the interlayer, and a mounting platform is also arranged at the lower end of the interlayer, and the mounting platform is rotatably connected to the outer wall of the high-pressure water pipe 5. The orientator 10 is fixedly connected to the upper end of the mounting platform, and a connecting piece is arranged between the lower end of the mounting platform and a second gear at the lowermost side, and the two ends of the connecting piece are respectively fixedly connected to the second gear and the lower end surface of the mounting platform; therefore, when a second gear at the lower side rotates, it drives the camera at the lower side to rotate, and at the same time, a second gear at the lower side rotates and drives the mounting platform to rotate through the connecting piece, so the orientator arranged on the mounting platform 10 also rotates simultaneously; the motors controlling the rotation of the three cameras 3 rotate simultaneously under the action of the microprocessor, and the orientator 10 also rotates together with the three cameras. For the convenience of measurement, three cameras 3 are provided in the present embodiment, and the three cameras 3 are evenly distributed along the circumferential direction of the metal tube 1; during the crack observation process, the orientator 10 maintains a fixed angle with the three numbered cameras, and the three cameras also maintain a fixed angle with each other. As the monitoring process starts, the three cameras rotate at a fixed rate, and the direction of the orientator 10 remains unchanged. The direction of the crack is determined by the data recorded by the microprocessor 8 and the orientation of the orientator 10.

[0032] Furthermore, in order to improve the clarity of the camera observation, a flocculant chamber 2 for storing a flocculant layer is also provided at one end of the interlayer near the ground pressure device disclosed in this embodiment, and a feed port and a discharge port for adding and releasing flocculants are also provided on the metal tube 1, and the feed port is provided on the upper side of the discharge port, and a push-out assembly for squeezing the flocculant out of the discharge port is also provided in the flocculant chamber 2. When on the ground, flocculant is added to the flocculant chamber 2 through the feed port, and the feed port of the metal tube 1 is provided with a blockage, and the discharge time of the discharge port can be controlled by the microprocessor 8. In order to facilitate the control of the discharge process of the flocculant, the push-out assembly disclosed in this embodiment includes an electronic push rod provided on the outer wall of the high-pressure water pipe 5, and a push plate is also provided at the end of the electronic push rod, and the push plate is slidably connected to the upper and lower side walls of the flocculant chamber 2, and the push rod is connected to the microprocessor 8. When the microprocessor controls the electronic push rod to move, the flocculant can be pushed out from the discharge port through the push plate, and then the flocculant enters the sealing section to precipitate the mud in the sealing section. After precipitation, the clarity in the measuring section can be improved, which is convenient for camera observation, and the release time of each measuring section of the flocculant is set in advance in the microprocessor 8. After the flocculant is released, the water pressure is maintained at 2-4Mpa and maintained for 50 minutes for flocculant flocculation. A first pressure sensor for detecting water pressure is also provided on the high-pressure water pipe 5, and the first pressure sensor is connected to the microprocessor 8.

[0033] In order to ensure the shooting effect, the frame rate of the camera 3 disclosed in this embodiment is 60-120, the resolution is 720p-1080p, and the waterproof level is IP68.

[0034] The present invention discloses a method for measuring hydraulic fracturing ground stress controlled by a microprocessor, based on the above-mentioned hydraulic fracturing ground stress measuring device controlled by a microprocessor, characterized in that it specifically comprises the following steps:

[0035] Step 1: sequentially connect the first packer, the in-situ stress measuring device, the second packer and the drill pipe, set a second pressure sensor on the second packer near the drill pipe, and connect the second pressure sensor to the microprocessor 8, and connect the high-pressure water pipe on the in-situ stress measuring device to the ground pressurizing device, and then release the connected whole into the selected measuring section, while keeping all components in a closed state;

[0036] Step 2: Specifically includes the following steps:

[0037] Step 2.1, start the surface pressurizing device to set the seal, that is, when the pressure difference between the pressure data measured by the first pressure sensor and the mud level pressure measured by the second pressure sensor is greater than 2 MPa, control the first packer and the second packer to expand to form a sealing section in the measuring section;

[0038] Step 2.2, after the sealing is completed, the difference between the two pressure sensors is controlled to be between 2-4 MPa through the ground pressurizing device, and then the flocculant is released through the microprocessor 8, and the water pressure continues to be maintained between 2-4 MPa and lasts for 50 minutes for flocculant flocculation;

[0039] Step 2.3, after the flocculation is completed, the microprocessor 8 controls the camera to start and drives the camera 3 to start rotating;

[0040] Step 3: Specifically includes the following steps:

[0041] Step 3.1, inject pressure into the isolation section through the high-pressure water pipe of the ground pressure device. When cracks appear, control the flow of the ground pressure device to keep the pressure basically unchanged. When the flow is stable, keep it for 1-3 minutes, and then continue to pressurize 2-3 times;

[0042] Step 3.2: After fracturing, close the surface pressurizing device and control the pressure relief of the two packers. After 30 minutes, the packers are completely depressurized. After the pressure relief is completed, move the connected whole to the next measuring section, and then repeat steps 2.1 to 2.3 to measure the next measuring section.

[0043] Step 4: Lift up the first packer, the geostress measuring device and the second packer, and export the data recorded in the microprocessor.

[0044] Step 5: Process the data in the microprocessor 8 to calculate the magnitude and direction of the ground stress.

[0045] The present invention discloses a microprocessor-controlled hydraulic fracturing ground stress measuring device, which integrates a fracturing device and a direction determination device into a unified device, records images of the crack formation process and the crack direction while fracturing, and the pressure data of the fracturing process, the image data of the crack formation process, and the direction data after the crack is formed are all controlled by the microprocessor 8 and stored in a storage card. After all the measuring sections are tested, the system is uniformly lifted to the ground, the data in the storage card is read, and the magnitude and direction of the ground stress are determined. Compared with the traditional hydraulic fracturing method, the ground stress measuring device disclosed in the invention can save the time of lifting the packer and the stamper back and forth when measuring, and greatly improves the success rate of the stamping. The traditional hydraulic fracturing method and the device both perform fracturing in the measuring section and observe the direction of the crack, but the measuring device disclosed in the present invention saves the time of lifting and lowering the stamper when measuring each measuring section in the traditional measurement process and improves the success rate. With the increase of the measuring sections, the measuring device disclosed in the present invention can save more time than the traditional process. The measuring device disclosed in the present invention can complete the determination of the direction of the single-hole crack and the determination of the magnitude of the principal stress in 12 hours or even less.

[0046] The embodiments described above are only preferred specific implementation methods of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belong to the protection scope of the present invention.

Claims

1. A microprocessor-controlled hydraulic fracturing in-situ stress measurement device, comprising a hydraulic fracturing assembly, wherein the hydraulic fracturing assembly comprises: A metal pipe (1), wherein a high-pressure water pipe (5) is arranged at the center of the metal pipe (1), a water inlet end of the high-pressure water pipe (5) is connected to a ground pressurizing device, a sandwich is formed between the high-pressure water pipe (5) and the metal pipe (1), a water outlet channel (4) is arranged on the side walls of the high-pressure water pipe (5) and the metal pipe (1), and a first pressure sensor for detecting water pressure is also arranged in the high-pressure water pipe (5), characterized in that it also includes: A plurality of cameras (3) are provided, wherein the plurality of cameras (3) are arranged in sequence along the axial direction of the metal tube (1), and the plurality of cameras (3) are all provided on the outer wall of the metal tube (1) via a rotating assembly, and the rotating assembly drives the cameras (3) to rotate around the metal tube (1), and the cameras (3) record the process of crack generation on the metal tube (1) when rotating; An orienter (10) is arranged at the lower end of the interlayer, the orienter (10) is fixedly connected to one of the cameras (3) at the lower side, and the rotation angle and orientation of the camera (3) are determined by the orienter (10); A microprocessor (8) is arranged in the interlayer, and the camera (3), the rotating assembly, the orienter (10), and the first pressure sensor are all connected to the microprocessor (8); Three cameras (3) are provided, and the three cameras (3) are evenly distributed along the circumferential direction of the metal tube (1); A flocculant chamber (2) for storing a flocculant layer is also provided at one end of the interlayer close to the ground pressure device, a feed port (6) and a discharge port (7) for adding and releasing flocculants are also provided on the side wall of the metal tube (1), the feed port is provided on the upper side of the discharge port, and a push-out assembly for squeezing the flocculant out of the discharge port is also provided in the flocculant chamber (2); During the crack observation process, the orientator (10) maintains a fixed angle with the three numbered cameras (3), and the three cameras (3) also maintain a fixed angle with each other. As the monitoring process begins, the three cameras rotate at a fixed rate, and the direction of the orientator (10) remains unchanged. The direction of the crack is determined by the data recorded by the microprocessor (8) and the orientation of the orientator (10).

2. A microprocessor-controlled hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: The rotating assembly comprises a motor arranged on the outer wall of the metal tube (1), the output shaft of the motor is parallel to the metal tube (1), a first gear is arranged on the output shaft of the motor, a second gear meshing with the first gear is sleeved on the outer side of the metal tube (1), the camera (3) is arranged on the second gear, and the motor is connected to the microprocessor (8).

3. A microprocessor-controlled hydraulic fracturing ground stress measuring device according to claim 2, characterized in that: A mounting platform is also provided at the lower end of the interlayer, the mounting platform is rotatably connected to the outer wall of the high-pressure water pipe (5), the orienter (10) is fixedly connected to the upper end of the mounting platform, a connecting piece is provided between the lower end of the mounting platform and the second gear at the lowermost side, and the two ends of the connecting piece are respectively fixedly connected to the second gear and the lower end surface of the mounting platform.

4. A microprocessor-controlled hydraulic fracturing ground stress measuring device according to claim 3, characterized in that: The ejection assembly comprises an electronic push rod arranged on the outer wall of the high-pressure water pipe (5), and a push plate is also arranged at the end of the electronic push rod, the push plate is slidably connected to the upper and lower side walls of the flocculant chamber (2), and the push rod is connected to the microprocessor (8).

5. The microprocessor-controlled hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: The frame rate of the camera (3) is 60-120, the resolution is 720p-1080p, and the waterproof grade is IP68.

6. A microprocessor-controlled hydraulic fracturing in-situ stress measurement method, based on a microprocessor-controlled hydraulic fracturing in-situ stress measurement device as claimed in claim 5, characterized in that: The specific steps include: Step 1, sequentially connect the hollow drill pipe, the first packer, the ground stress measuring device, and the second packer, set a second pressure sensor on the side of the first packer close to the drill pipe, and connect the second pressure sensor to the microprocessor (8), and connect the drill pipe to the ground pressurizing device at the same time, and then release the connected whole into the selected measuring section, while keeping all components in a closed state; Step 2: starting the ground pressurizing device to set the seal, and after the setting is completed, flocculation is performed. After the flocculation is completed, the camera (3) is controlled by the microprocessor (8) to start rotating; Step 3: Perform fracturing. After the fracturing is completed, turn off the camera (3) and the ground pressurizing device, and release the pressure through the ground pressurizing device. After the pressure release is completed, move the connected whole to the next measuring section, and repeat step 2 to measure the next measuring section; Step 4: lifting the first packer, the geostress measuring device and the second packer, and exporting the data recorded in the microprocessor; Step 5: Data processing to calculate the magnitude and direction of ground stress.

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