A method for detecting residual stress in an experimental comprehensive testing system of an expanded tube

Abstract

The application discloses a residual stress detection method in an expansion pipe experimental comprehensive test system. The expansion pipe experimental comprehensive test system is mainly composed of a hydraulic system, an expansion pipe, an expansion cone, a strain collection system, an expansion pipe post-expansion shearing device, an expansion pipe post-expansion anti-external extrusion device and the residual stress detection method. The residual stress detection method is characterized in that the expansion cone is driven to expand the expansion pipe in the axial direction through the hydraulic system, the axial and circumferential strains of the expansion pipe wall during the expansion are collected, the moving distance of the expansion cone is collected in real time through a displacement sensor, the pressure value of the oil pressure of the compression system is collected through a pressure sensor, and then the driving force value during the expansion process is calculated; the post-expansion expansion pipe is subjected to shearing and pressure extrusion resistance experiments, and the residual stress value of the pipe body is detected by using the ring cutting method and the strip cutting method. The residual stress detection method in the expansion pipe experimental comprehensive test system can comprehensively improve the expansion pipe experimental efficiency and the data collection accuracy, and provides reliable data support for the expansion pipe expansion mechanism research.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of residual stress detection method in the comprehensive test system of expansion pipe experiment, belong to important oil exploitation and natural gas development supporting tool field. BACKGROUND

[0002] With the continuous consumption of resources and the increase of oil exploitation difficulty, casing failure often occurs in the process of oil and gas exploitation due to casing wear, corrosion and other factors, and expansion pipe technology is the best method to solve the failure of injection-production pipe network. Expansion pipe technology refers to the expansion casing is lowered to the well, the expansion casing is connected through threads, the hydraulic pressure of the expansion cone below is raised to push the expansion cone from bottom to top, and the expansion casing is expanded by cold extrusion of the expansion cone to achieve the required size. Expansion pipe technology is applied to cementing, well completion, repairing damaged casing or supporting the well section prone to collapse.

[0003] Because the expansion pipe needs to be applied to the well, a large number of experimental simulation verification needs to be carried out, expansion experiments of different expansion rates of the expansion pipe are carried out, expansion pipe shear experiments are carried out by simulating formation slip, and anti-external extrusion experiments are carried out by simulating the expansion pipe under formation pressure. The residual stress of the expansion pipe is the core key to affect the expansion pipe forming, and the ring cutting method and the strip cutting method are used to detect the size of the residual stress of the expansion pipe. Sufficient experimental and evaluation data are the key to the successful application of the expansion pipe in the well.

[0004] Therefore, a residual stress detection method in the comprehensive test system of expansion pipe experiment is designed, which is the key to improving the application efficiency of the expansion pipe. SUMMARY

[0005] The purpose of the present application is to provide a residual stress detection method in the comprehensive test system of expansion pipe experiment, which is used to improve the efficiency of the expansion pipe experiment and reduce the accidental situation after the expansion pipe is lowered into the well.

[0006] To achieve the purpose of solving the above problems, the technical scheme adopted by the present application is to provide a residual stress detection method in the comprehensive test system of expansion pipe experiment. The expansion pipe experiment comprehensive test system is mainly composed of a plug, a connecting cylinder, a strain gauge, an expansion pipe, a distance sensor, an expansion cone, a piston rod, a piston, an end cover, a high-pressure pipeline, a pressure sensor, a hydraulic system, a guide rail, a wire, a centralizer, a guide rod, a signal conditioner, an analysis processing system, a fixed shear shell cylinder, a fixed shell, a shell cylinder support, a sliding shear shell cylinder, an anti-external extrusion threaded plug, a high-pressure pipe connector, a sealing plug, an anti-external extrusion shell, an expansion pipe drill hole and a handheld strain gauge.

[0007] The inflation system, the inflation pipe is placed in the connecting cylinder, the both ends of the inflation pipe are fixed by the plug and the inflation cone, the centralizer, the inflation pipe body is supported by the guide rail, the connecting cylinder and the plug are connected by the trapezoidal thread, the screwing distance of the thread controls the inflation pipe of different lengths to be clamped between the plug and the inflation cone. The hydraulic system pressurizes the right space of the piston through the high-pressure pipeline and the end cover, the piston moves to the left to push the piston rod to drive the inflation cone to inflate the inflation pipe, the piston rod advances to record the displacement distance of the inflation cone through the displacement sensor, when the inflation cone passes the inflation pipe position with the strain gauge, the axial and radial strain of the inflation pipe are recorded, at the same time, the pressure sensor, the displacement sensor and the strain gauge transmit the data into the signal conditioner through the wire, the signal conditioner distributes the data into the analysis processing system to record the data changes continuously. The hydraulic system pressurizes through the high-pressure pipeline on the upper part of the device to push the piston to move to the right, at the same time, the piston rod drives the inflation cone to exit from the inflation pipe, and the inflation pipe completes the inflation and data collection at the same time.

[0008] After the inflation is completed, the inflation pipe is taken out, the inflated inflation pipe is placed in the concentric fixed shearing shell cylinder and the sliding shearing shell cylinder, the fixed shearing shell cylinder and the sliding shearing shell cylinder are placed in the fixed shell and are separated by 100 mm, there is a 5 mm gap between the outer wall of the fixed shearing shell cylinder and the sliding shearing shell cylinder and the inner wall of the fixed shell, the sliding shearing shell cylinder is supported by the shell cylinder support, after being fixed, the hydraulic pressure is used to press downward, at the same time, the shell cylinder support is withdrawn, when the inflation pipe is sheared and extruded, the strain gauge is extruded, the strain data of the inflation pipe under shearing is recorded, and the shearing experiment of the inflation pipe is completed.

[0009] After the shearing of the inflation pipe with different inflation rates is completed, the strain data of the inflation pipe under the shearing experiment is statistically processed, and the stress change under the shearing condition is converted through the formula.

[0010] After the inflation, the inflation pipe is taken out, the inflated inflation pipe is placed in the anti-external extrusion shell, at the same time, the sealed plug is used to fix the both ends of the inflation pipe in the axial direction, the sealed plug is used to seal the inside and outside of the inflation pipe, the anti-external extrusion threaded plug seals the inflation pipe and the anti-external extrusion shell, and the threaded connection is used, the anti-external extrusion shell is connected with the high-pressure pipe joint, the high-pressure pipe joint is connected with the high-pressure pipeline, the high-pressure liquid enters the annulus between the inflation pipe and the anti-external extrusion shell through the high-pressure pipeline and the high-pressure pipe joint to press, and the inflation pipe stops pressing when it is extruded by the external pressure.

[0011] When the inflation pipe is extruded, the change of the hydraulic data is recorded, the hydraulic data is statistically arranged, and is used for the evaluation of the anti-external extrusion performance.

[0012] After the expansion is finished, the expansion pipe is taken out, the expansion pipe is cut into pieces according to the equal division of the axial length L=100mm, drilling operation is carried out on the outer wall of the expansion pipe after cutting, each pair of drilling is separated by a=60mm, and a handheld strain gauge is used to record the drilling spacing of the expansion pipe, the axial region of each pair of holes is cut into strips, the drilling spacing b of each pair of expansion pipe holes after cutting is measured, and finally the axial residual stress of the expansion pipe is calculated according to the Hook's law. The expansion pipe circumferential residual stress is tested by using the ring cutting method, the expanded expansion pipe is taken out, the expansion pipe is divided into pieces along the longitudinal direction according to the equal division of L=100mm, the outer diameter change of the expansion pipe before and after the division is measured, and the circumferential residual stress of the expansion pipe is calculated through the residual stress formula.

[0013] Compared with the prior art, the beneficial effects of the present application are that: the residual stress detection method in the expansion pipe experimental comprehensive test system can greatly improve the efficiency of the expansion pipe experimental stage and save the time cost of the expansion pipe tool in the experimental preparation stage. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a principle diagram of expansion operation in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0015] Figure 2 It is a strain gauge pasting method diagram of the expansion pipe in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0016] Figure 3 It is a AA section view of the expansion pipe strain gauge pasting position in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0017] Figure 4 It is a shearing experiment device diagram of the expansion pipe after expansion in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0018] Figure 5 It is an anti-external extrusion experiment device diagram of the expansion pipe after expansion in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0019] Figure 6 It is a method for detecting the residual stress of the expansion pipe after expansion by using the ring cutting method and the cutting method in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0020] Figure 7 It is a calculation formula related to the calculation of the circumferential residual stress of the expansion pipe by using the ring cutting method in the residual stress detection method in the expansion pipe experimental comprehensive test system of the present application;

[0021] In the figure: 1 - end cap; 2 - connecting cylinder; 3 - strain gauge; 4 - expansion tube; 5 - displacement sensor; 6 - expansion cone; 7 - piston rod; 8 - piston; 9 - end cap; 10 - high pressure pipeline; 11 - pressure sensor; 12 - hydraulic system; 13 - guide rail; 14 - wire; 15 - centralizer; 16 - guide rod; 17 - signal conditioner; 18 - analysis processing system; 19 - fixed shear shell cylinder; 20 - fixed shell; 21 - shell cylinder support; 22 - sliding shear shell cylinder; 23 - anti-external extrusion threaded end cap; 24 - high pressure pipe connector; 25 - sealing end cap; 26 - anti-external extrusion shell; 27 - expansion tube drilling; 28 - handheld strain meter. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described with reference to the accompanying drawings.

[0023] The present application provides a residual stress detection method in an expansion tube experimental comprehensive test system, characterized by the residual stress detection method, in the expansion system, the expansion tube is placed in the connecting cylinder, and the two ends are fixed by the end cap and the expansion cone and the centralizer, the tube body is supported by the guide rail, the connecting cylinder and the end cap are connected through trapezoidal threads, and the screwing distance of the threads controls the clamping of expansion tubes of different lengths. The data acquisition system is started, the hydraulic system pressurizes the right space of the piston through the high pressure pipeline and the end cap, the piston moves to the left to push the piston rod to drive the expansion cone to expand the expansion tube, the piston rod advances through the displacement sensor to record the displacement distance of the expansion cone, and when the expansion cone passes through the expansion tube position with the strain gauge, the axial and radial strains of the expansion tube are recorded, and the pressure sensor, the displacement sensor and the strain gauge transmit data into the signal conditioner through the wire, the signal conditioner distributes data to enter the analysis processing system to continuously record the pressure change. The hydraulic system pressurizes through the high pressure pipeline on the upper part of the device to push the piston to move to the right, and at the same time, the piston rod drives the expansion cone to exit from the expansion tube, and the expansion tube completes the expansion and data acquisition.

[0024] The present application provides a residual stress detection method in an expansion tube experimental comprehensive test system, characterized by the residual stress detection method, after the expansion is completed, the expansion tube is taken out, and the expanded expansion tube is placed in the concentric fixed shear shell cylinder and sliding shear shell cylinder, the sliding shear shell cylinder is supported by the shell cylinder support, and after being fixed, the hydraulic pressure is pressed downward, and at the same time, the shell cylinder support is withdrawn, when the expansion tube is sheared and extruded, the strain gauge is extruded, the strain data of the expansion tube when sheared are recorded, and the expansion tube shearing experiment is completed.

[0025] The application provides a residual stress detection method in an expansion pipe experiment comprehensive test system, characterized by the residual stress detection method, after expansion, the expansion pipe is taken out, the expanded expansion pipe is placed in an anti-external extrusion shell, meanwhile, a sealing plug is used to axially fix the two ends of the expansion pipe, the sealing plug is used to seal the inside and outside of the expansion pipe, an anti-external extrusion threaded plug seals the expansion pipe and the anti-external extrusion shell, and the anti-external extrusion shell is connected with a high-pressure pipe joint through screw connection, the high-pressure pipe joint is connected with a high-pressure pipeline, high-pressure liquid enters the annulus between the expansion pipe and the anti-external extrusion shell through the high-pressure pipeline and the high-pressure pipe joint to press, when the expansion pipe collapses under external extrusion pressure, the pressing is stopped, and the pressure data change is recorded in real time through a pressure sensor and an analysis processing system.

[0026] The application provides a residual stress detection method in an expansion pipe experiment comprehensive test system, characterized by the residual stress detection method, after expansion, the expansion pipe is taken out, the expanded expansion pipe is placed in an anti-external extrusion shell, meanwhile, a sealing plug is used to axially fix the two ends of the expansion pipe, the sealing plug is used to seal the inside and outside of the expansion pipe, an anti-external extrusion threaded plug seals the expansion pipe and the anti-external extrusion shell, and the anti-external extrusion shell is connected with a high-pressure pipe joint through screw connection, the high-pressure pipe joint is connected with a high-pressure pipeline, high-pressure liquid enters the annulus between the expansion pipe and the anti-external extrusion shell through the high-pressure pipeline and the high-pressure pipe joint to press, when the expansion pipe collapses under external extrusion pressure, the pressing is stopped, and the pressure data change is recorded in real time through a pressure sensor and an analysis processing system. The application provides a residual stress detection method in an expansion pipe experiment comprehensive test system, characterized by the residual stress detection method, after expansion, the expansion pipe is taken out, the expanded expansion pipe is placed in an anti-external extrusion shell, meanwhile, a sealing plug is used to axially fix the two ends of the expansion pipe, the sealing plug is used to seal the inside and outside of the expansion pipe, an anti-external extrusion threaded plug seals the expansion pipe and the anti-external extrusion shell, and the anti-external extrusion shell is connected with a high-pressure pipe joint through screw connection, the high-pressure pipe joint is connected with a high-pressure pipeline, high-pressure liquid enters the annulus between the expansion pipe and the anti-external extrusion shell through the high-pressure pipeline and the high-pressure pipe joint to press, when the expansion pipe collapses under external extrusion pressure, the pressing is stopped, and the pressure data change is recorded in real time through a pressure sensor and an analysis processing system.

Claims

1. A method for detecting residual stress in an expansion tube experimental integrated testing system, the expansion tube experimental integrated testing system mainly consists of a plug (1), a connecting cylinder (2), a strain gauge (3), an expansion tube (4), a displacement sensor (5), an expansion cone (6), a piston rod (7), a piston (8), an end cap (9), a high-pressure pipeline (10), a pressure sensor (11), a hydraulic system (12), a guide rail (13), a wire (14), a centralizer (15), a guide rod (16), a signal mediator (17), an analysis and processing system (18), and a solid... The system consists of a fixed shear outer shell (19), a fixed shell (20), an outer shell support (21), a sliding shear outer shell (22), an anti-extrusion threaded plug (23), a high-pressure pipe connector (24), a sealing plug (25), an anti-extrusion shell (26), an expansion pipe drill (27), and a handheld strain gauge (28); its technical feature lies in the residual stress detection method: in the expansion system, the expansion pipe (4) is placed in the connecting cylinder (2), and both ends are fixed by plugs (1), expansion cones (6), and stabilizers (15). The pipe body is supported by guide rails ( 13) The support, connecting cylinder (2) and plug (1) are connected by trapezoidal thread. The thread advance distance controls the clamping of expansion tubes (4) of different lengths. The hydraulic system (12) pressurizes the space on the right side of piston (8) through high-pressure pipeline (10) and end cap (9). Piston (8) moves to the left, thereby pushing piston rod (7) to drive expansion cone (6) to expand expansion tube (4). The piston rod (7) advances and the displacement distance of expansion cone (6) is recorded by displacement sensor (5). When expansion cone (6) passes the strain gauge (3) and expansion tube (4) position The expansion tube (4) is recorded in axial and radial strain. At the same time, the pressure sensor (11), displacement sensor (5), and strain gauge (3) transmit data to the signal conditioner (17) through the wire (14). After the signal conditioner (17) distributes the data, it enters the analysis and processing system (18) to continuously record the data changes. The hydraulic system pressurizes through the high-pressure pipeline (10) at the top of the device to push the piston (8) to move to the right. At the same time, the piston rod (7) drives the expansion cone (6) to exit from the expansion tube (4). The expansion tube (4) completes expansion and data acquisition.

2. The residual stress detection method in the comprehensive testing system for expansion tubes according to claim 1, characterized in that... Residual stress detection method: After the expansion is completed, the expansion tube (4) is taken out and placed inside the concentric fixed shear shell (19) and sliding shear shell (22). The fixed shear shell (19) and sliding shear shell (22) are placed inside the fixed shell (20) and are 100mm apart. The outer wall of the fixed shear shell (19) and sliding shear shell (22) is 5mm away from the inner wall of the fixed shell (20). The sliding shear shell (22) is supported by the shell support (21). After fixing, hydraulic pressure is used to press down and the shell support (21) is removed at the same time. When the displacement of the sliding shear shell (22) reaches 2 / 3 of the diameter of the expansion tube (4), the expansion tube (4) is deformed by shear compression and the strain gauge (3) is compressed. The strain data of the expansion tube (4) under shear is recorded by the analysis and processing system (18) to complete the shear test of the expansion tube (4).

3. The residual stress detection method in the comprehensive testing system for expansion tubes according to claim 1, characterized in that... Residual stress detection method: After expansion, take out the expansion tube (4) and place the expanded expansion tube (4) into the anti-extrusion shell (26). At the same time, use the sealing plug (25) to fix the expansion tube (4) axially at both ends. Use the sealing plug (25) to seal the expansion tube (4) inside and out. Use the anti-extrusion threaded plug (23) to seal the expansion tube (4) and the anti-extrusion shell (26) and use thread connection. The thread section is 60mm long. The anti-extrusion shell (26) is connected to the high pressure pipe joint (24). The high pressure pipe joint (24) is connected to the high pressure pipeline (10). High pressure liquid enters the annulus between the expansion tube (4) and the anti-extrusion shell (26) through the high pressure pipeline (10) and the high pressure pipe joint (24) to pressurize. When the expansion tube (4) collapses due to external extrusion pressure, stop pressurizing. Record the pressure data changes in real time through the pressure sensor (11) and the analysis and processing system (18).

4. The residual stress detection method in the comprehensive testing system for expansion tubes according to claim 1, characterized in that... Residual stress detection method: After the expansion is completed, the expansion tube is taken out and the expansion tube (4) is cut into blocks of 100mm length. After the blocks are cut, the expansion tube is drilled (27) on the outer wall of the expansion tube. The holes are spaced a = 60mm apart. The spacing between the holes is recorded using a handheld strain gauge (28). The spacing between the holes of each pair of expansion tubes is measured three times and the average value is taken. The axial area where each pair of holes is located is cut into strips. The spacing between the holes of each pair of expansion tubes after the strips is measured b. Finally, the axial residual stress of the expansion tube is calculated according to Hooke's law. The circumferential residual stress of the expansion tube (4) is tested using the ring cutting method. The expanded expansion tube (4) is taken out and the expansion tube (4) is divided into 100mm sections along the longitudinal direction. The change in the outer diameter of the expansion tube (4) before and after the division is measured. The circumferential residual stress of the expansion tube is calculated using the residual stress formula.

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