Device for detecting air tightness of thread buckle under combined loading condition of casing string

Abstract

The invention provides a device for detecting the air tightness of a thread buckle under the combined loading working condition of a casing string, and relates to the technical field of oil drilling and completion, and the device comprises a detection platform which is used for fixing a first casing and a second casing, and enabling the end face of the first casing to be attached to the end face of the second casing, so as to form a gas channel; the pressurizing assembly is mounted on the detection platform and is used for communicating with the first sleeve so as to introduce gas into the first sleeve; the pressure relief assembly is mounted on the detection platform and is used for being communicated with the second sleeve so as to release gas flowing into the second sleeve; the measuring assembly comprises a barometer and a controller, and the barometer is used for being installed on the outer wall of the second casing pipe so as to monitor the air pressure change in the second casing pipe; the controller is electrically connected with the barometer so as to collect measurement data of the barometer. According to the air tightness detection device provided by the invention, air tightness detection can be carried out on the threaded buckle of the casing string under the simulated composite loading working condition, and the device can be better close to the field working condition.

Description

Technical Field

[0001] The present application relates to the technical field of oil drilling and completion, and particularly relates to a device for detecting the airtightness of thread joints under the compound loading conditions of a casing string. Background Art

[0002] Unconventional oil and gas reservoirs in China, such as shale gas and shale oil formations, are characterized by thin thickness and strong heterogeneity. During the drilling process, in order to ensure that the wellbore is within the reservoir, it is necessary to continuously adjust the wellbore trajectory, which ultimately leads to a complex wellbore trajectory. When the casing is run in, due to the long horizontal section and large dogleg severity, it is difficult for the casing to be run in place at one time. The method of lifting and flushing is often used to generate impact loads on the casing, so as to run it into the target formation.

[0003] However, the bending of the pipe string and the axial impact load may cause serious fatigue damage to the thread joints, reduce the airtightness ability, and in severe cases, the thread joints will break during the casing running process, resulting in the interruption of the cementing operation. At the same time, during the multi-stage fracturing process, the thread joints are subjected to periodic casing internal pressure, which may further increase the fatigue damage of the thread joints, and in severe cases, lead to the fracture of the thread joints and even the abandonment of the wellbore.

[0004] At present, the existing physical simulation test devices for casing strings can realize the research on the composite loading of uniform external extrusion load, temperature load and bending load, but lack the measurement devices and methods for the airtightness of casing thread joints under the compound loading conditions of the casing string bearing axial load, bending load and cyclic internal pressure of the casing. Summary of the Invention

[0005] In view of this, the present application provides a device for detecting the airtightness of thread joints under the compound loading conditions of a casing string, which can detect the airtightness of the thread joints of the casing string.

[0006] To achieve the above object, a device for detecting the airtightness of thread joints under the compound loading conditions of a casing string provided by the present application adopts the following technical solutions:

[0007] An embodiment of the present application provides a device for detecting the airtightness of thread joints under the compound loading conditions of a casing string, including:

[0008] A detection platform for fixing a first casing and a second casing and making the end face of the first casing fit with the end face of the second casing to form a gas channel;

[0009] A pressurizing assembly installed on the detection platform and used for communicating with the first casing to introduce gas into the first casing;

[0010] A pressure relief assembly installed on the detection platform and used for communicating with the second casing to release the gas flowing into the second casing;

[0011] The measuring component includes a barometer and a controller. The barometer is used to be installed on the outer wall of the second sleeve to monitor the air pressure change in the second sleeve. The controller is electrically connected to the barometer to collect the measurement data of the barometer.

[0012] In a possible implementation, the pressurizing component includes an air pressure pump. The air pressure pump is used to communicate with the air inlet of the first sleeve through a first conduit. The controller is electrically connected to the air pressure pump to control the air pressure pump to introduce the gas into the first sleeve.

[0013] In a possible implementation, the pressure relief component includes a pressure relief valve. The pressure relief valve is used to communicate with the air outlet of the second sleeve through a second conduit to release the gas from the second sleeve.

[0014] In a possible implementation, a first placement hole adapted to the first sleeve is provided on the detection platform. The first placement hole is used for the first sleeve to be inserted into the detection platform.

[0015] It further includes a mounting seat. The mounting seat is slidably arranged on the detection platform, and a second placement hole adapted to the second sleeve is provided on the mounting seat. The second placement hole is used for the second sleeve to be inserted into the detection platform.

[0016] In a possible implementation, it further includes a coupling. The coupling is used to be sleeved on the joint of the first sleeve and the second sleeve.

[0017] In a possible implementation, it further includes a pressing component. The pressing component is installed on the detection platform, and the moving end of the pressing component abuts against the outer wall of the coupling. The controller is electrically connected to the pressing component to control the pressing component to apply a downward pressure on the coupling.

[0018] In a possible implementation, the pressing component includes a driving rod and a pressing member. The driving rod is installed on the detection platform. The controller is electrically connected to the driving rod to control the driving rod to rotate.

[0019] The pressing member is sleeved on the driving rod and is threadedly connected to the driving rod to drive the pressing member to move up and down.

[0020] In a possible implementation, it further includes a pushing member. The pushing member is installed on the detection platform, and the moving end of the pushing member abuts against the mounting seat.

[0021] The controller is electrically connected to the pushing member to control the pushing member to push the mounting seat to slide in a direction close to the first sleeve.

[0022] In a possible implementation, a displacement sensor is further included, and the displacement sensor is used to be installed on the outer walls of the first sleeve and the second sleeve to monitor the shape changes of the first sleeve and the second sleeve;

[0023] The controller is electrically connected to the displacement sensor to collect the measurement data of the displacement sensor.

[0024] In a possible implementation, the number of the displacement sensors is set to be multiple, and the multiple displacement sensors are respectively arranged at intervals along the extending directions of the first sleeve and the second sleeve.

[0025] A thread joint airtightness detection device under the compound loading condition of a casing string provided by an embodiment of the present application includes a detection platform, a pressurizing assembly, a pressure relief assembly, and a measurement assembly, wherein the measurement assembly includes a pressure gauge and a controller.

[0026] When performing airtightness detection on the casing string, first, two sections of casings are respectively fixed on the detection platform, and it is ensured that the end faces of the two sections of casings are closely attached to form a sealed space inside the two sections of casings; subsequently, the detection steps are divided into three steps: first, pressure testing, that is, making the whole casing only bend vertically downward; the second step is to perform multiple axial pressure cycle loading and unloading to measure the airtightness performance of the thread joint after the axial pressure cycle loading and unloading, and after the last axial pressure cycle loading and unloading is completed, perform another pressure pump pressurization, and after the pressure gauge reading drops to a certain stable value, read the value, which is recorded as reading one, that is, the airtightness performance of the thread joint under the condition of cyclic axial pressure. If reading one is smaller than the maximum bearing pressure of the thread joint, it is determined that its airtightness is reduced; the third step is to perform multiple internal pressure cycle loading and unloading to measure the airtightness performance of the thread joint after the cyclic internal pressure loading and unloading, and after the last cyclic internal pressure loading and unloading is completed, perform another pressure pump pressurization, and after the pressure gauge reading drops to a certain stable value, read the value, which is recorded as reading two. If reading two is less than reading one, it is determined that the airtightness performance of the thread joint is reduced after bearing the cyclic internal pressure loading and unloading.

[0027] Compared with the prior art, a thread joint airtightness detection device and method under the compound loading condition of a casing string provided by the present application detect the airtightness of the thread joint under the condition of the compound loading of the bending load, axial load, and cyclic internal pressure of the casing string by simulating the processes of the bending of the casing string, the up-and-down impact, and the rise and fall of the internal pressure of the casing during hydraulic fracturing, and can simulate the service process of the thread joint of the casing string in the oil and gas well under this condition. In summary, the airtightness detection device provided by the present application has the function of detecting the airtightness of the thread joint under the condition of the compound loading of the bending load, axial load, and cyclic internal pressure of the casing string, and can better approximate the on-site working condition. Description of the Drawings

[0028] The following is a detailed description of the specific implementation manners of the embodiments of the present application in conjunction with the accompanying drawings. It should be understood that the specific implementation manners described herein are only for explaining and interpreting the embodiments of the present application, and the embodiments of the present application are not limited to the following specific implementation manners.

[0029] Figure 1 It is a schematic structural diagram of a thread joint airtightness detection device under the compound loading condition of a casing string provided by an embodiment of the present application;

[0030] Figure 2 It is a front view of a thread joint airtightness detection device under the compound loading condition of a casing string provided by an embodiment of the present application;

[0031] Figure 3 It is a top view of a thread joint airtightness detection device under the compound loading condition of a casing string provided by an embodiment of the present application.

[0032] Explanation of reference numerals:

[0033] 100 - Detection platform;

[0034] 110 - First placement hole;

[0035] 200 - Pressurizing assembly;

[0036] 210 - Air pressure pump; 220 - First conduit;

[0037] 300 - Pressure relief assembly;

[0038] 310 - Pressure relief valve; 320 - Second conduit;

[0039] 400 - Measuring assembly;

[0040] 410 - Pressure gauge; 420 - Controller;

[0041] 500 - Mounting seat;

[0042] 510 - Second placement hole;

[0043] 600 - Coupling;

[0044] 700 - Pressing assembly;

[0045] 710 - Driving rod; 720 - Pressing member;

[0046] 800 - Pushing member;

[0047] 900 - Displacement sensor;

[0048] 1000 - First casing;

[0049] 1100 - Second casing.

[0050] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and more detailed descriptions will be provided hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the embodiments of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiments

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will describe the technical solutions in the embodiments of the present application and how the technical solutions in the embodiments of the present application solve the above-mentioned technical problems clearly and completely with specific embodiments in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0052] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be construed in a broad sense. For example, it may be a fixed connection, or an indirect connection through an intermediate medium, or the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0053] In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the embodiments of the present application.

[0054] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such used data may be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein.

[0055] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0056] In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that comprises a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0057] Unconventional oil and gas reservoirs in China, such as shale gas and shale oil formations, are characterized by thin thickness and strong heterogeneity. During the drilling process, in order to ensure that the wellbore is within the reservoir, it is necessary to continuously adjust the wellbore trajectory, which ultimately results in a complex wellbore trajectory. When running the casing, due to the long horizontal section and large dogleg severity, it is difficult to run the casing in place in one go. The method of lifting and flushing is often used to generate impact loads on the casing, so as to run it into the target formation.

[0058] However, the bending of the pipe string and the axial impact load may cause serious fatigue damage to the thread joints, reduce the gas sealing ability, and in severe cases, the thread joints will break during the casing running process, resulting in the interruption of the cementing operation. At the same time, during the multi-stage fracturing process, the thread joints bear the periodic internal casing pressure, which may further increase the fatigue damage of the thread joints, and in severe cases, lead to the fracture of the thread joints and even the abandonment of the wellbore.

[0059] At present, the existing physical simulation test devices for casing strings can achieve the combined loading research of uniform external extrusion load, temperature load and bending load, but lack the measuring devices and methods for the gas tightness of casing thread joints under the working condition of combined loading of axial load, bending load and internal casing pressure cycle on the casing string.

[0060] Based on this, a device for detecting the air tightness of thread joints under the combined loading condition of a casing string provided by the embodiments of the present application includes a detection platform, a pressurizing component, a pressure relief component and a measuring component, wherein the measuring component includes a pressure gauge and a controller.

[0061] When conducting airtightness detection on a casing string, first fix two sections of the casing on the detection platform respectively, and ensure that the end faces of the two sections of the casing are in close contact to form a sealed space inside the two sections of the casing. Subsequently, the detection steps are divided into three steps: First, conduct a pressure test, that is, make the whole casing bend only vertically downward. The second step is to perform multiple axial pressure cycle loading and unloading to measure the gas tightness performance of the thread after the axial pressure cycle loading and unloading. And after the last axial pressure cycle loading and unloading is completed, conduct another air pressure pump pressurization. After the air pressure gauge reading drops to a certain stable value, read the value, record it as reading one, which is the gas tightness performance of the thread under the condition of cyclic axial pressure. If reading one is smaller than the maximum bearing pressure of the thread, it is judged that its gas tightness has decreased. The third step is to perform multiple internal pressure cycle loading and unloading to measure the gas tightness performance of the thread after the cyclic internal pressure loading and unloading. And after the last cyclic internal pressure loading and unloading is completed, conduct another air pressure pump pressurization. After the air pressure gauge reading drops to a certain stable value, read the value, record it as reading two. If reading two is less than reading one, it is judged that the gas tightness performance of the thread has decreased after bearing the cyclic internal pressure loading and unloading.

[0062] Compared with the prior art, the casing string thread airtightness detection device and method provided by the present application simulate the processes of casing string bending, lifting and lowering, and internal pressure rise and fall of hydraulic fracturing of the casing, detect the gas tightness of the thread under the condition of combined loading of bending load, axial load and cyclic internal pressure of the casing string, and can simulate the service process of the casing string thread in an oil and gas well under this condition. In summary, the airtightness detection device provided by the present application has the function of detecting the airtightness of the thread under the condition of combined loading of bending load, axial load and cyclic internal pressure of the casing string, and can better approximate the on-site working conditions.

[0063] The technical solutions of the embodiments of the present application will be described in detail below with specific embodiments in conjunction with the accompanying drawings. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0064] Refer to Figures 1 to 3As shown in the figure, an airtightness detection device for screw threads under the compound loading condition of a casing string provided by an embodiment of the present application includes a detection platform 100, which is used to fix a first casing 1000 and a second casing 1100, and make the end face of the first casing 1000 fit with the end face of the second casing 1100 to form a gas channel; a pressurizing assembly 200, installed on the detection platform 100 and used to communicate with the first casing 1000 to introduce gas into the first casing 1000; a pressure relief assembly 300, installed on the detection platform 100 and used to communicate with the second casing 1100 to release the gas flowing into the second casing 1100; a measurement assembly 400, including a pressure gauge 410 and a controller 420. The pressure gauge 410 is used to be installed on the outer wall of the second casing 1100 to monitor the air pressure change in the second casing 1100; the controller 420 is electrically connected to the pressure gauge 410 to collect the measurement data of the pressure gauge 410.

[0065] When detecting the airtightness of the casing string, first fix the two sections of the casing on the detection platform 100 respectively, and ensure that the end faces of the two sections of the casing are closely fitted to form a sealed space inside the two sections of the casing; subsequently, the detection steps are divided into three steps: First, perform a pressure test, that is, make the whole casing only bend vertically downward; the second step is to measure the gas tightness performance of the screw thread after the axial pressure is cyclically loaded and unloaded: open the air pressure pump 210 to inject nitrogen gas at a certain pressure, then close the air pressure pump 210 and wait for a period of time to observe the reading of the pressure gauge, then open the pressure relief valve 310 to relieve the pressure, repeat the axial pressure loading and unloading multiple times, and after each loading and unloading is completed, observe whether the pressure indication shown on the pressure gauge 410 increases. If it is still increasing, it means that the airtightness of the casing screw thread is good. Then, after the multiple axial pressure loading and unloading are completed, perform another pressurization of the air pressure pump 210, and wait until the reading of the pressure gauge 410 tends to drop to a certain stability and then read the value, which is recorded as reading one, that is, the gas tightness performance of the screw thread after the cyclic axial pressure condition; the third step is to measure the gas tightness performance of the screw thread after the cyclic internal pressure is loaded and unloaded: open the air pressure pump 210 to inject nitrogen gas at a certain pressure to make the reading of the pressure gauge 410 higher than the highest value in the second step, then close the air pressure pump 210 and wait for a period of time to observe the reading of the pressure gauge 410, then open the pressure relief valve 310 to relieve the pressure, repeat the internal pressure loading and unloading multiple times, and then perform another pressurization of the air pressure pump 210. When the reading of the pressure gauge 410 tends to be stable, read the value, which is recorded as reading two, that is, the gas tightness performance of the screw thread after the cyclic internal pressure condition. If reading two is less than reading one, it is determined that the gas tightness performance of the screw thread decreases after bearing the cyclic internal pressure loading and unloading.

[0066] Compared with the prior art, a device and method for detecting the airtightness of a threaded connection under the combined loading conditions of a casing string provided by the present application can detect the airtightness of the threaded connection under the combined loading conditions of bending load, axial load and cyclic internal pressure of the casing string by simulating the processes of casing string bending, lifting and lowering, and internal pressure increase and decrease during hydraulic fracturing of the casing string, and can simulate the service process of the threaded connection of the casing string in an oil and gas well under this condition. In summary, the airtightness detection device provided by the present application has the function of detecting the airtightness of the threaded connection under the combined loading conditions of bending load, axial load and cyclic internal pressure of the casing string, and can better approximate the on-site conditions.

[0067] Referring to Figure 1 As shown, in some embodiments, the pressurizing assembly 200 includes a gas pressure pump 210. The gas pressure pump 210 is used to communicate with the air inlet of the first casing 1000 through a first conduit 220. The controller 420 is electrically connected to the gas pressure pump 210 to control the gas pressure pump 210 to introduce gas into the first casing 1000.

[0068] Using the gas pressure pump 210 as the gas transmission device, it can pressurize the gas to provide power for the input of the gas and improve the input efficiency of the gas. At the same time, it should be noted that in the above embodiments, the high-pressure detection gas is nitrogen. Compared with other types of gases, nitrogen has the characteristics of low cost and stable properties. The staff can also flexibly adjust the type of gas according to the actual detection requirements, which will not be elaborated here one by one.

[0069] Referring to Figure 1 As shown, in some embodiments, the pressure relief assembly includes a pressure relief valve 310. The pressure relief valve 310 is used to communicate with the air outlet of the second casing 1100 through a second conduit 320 to release the gas from the second casing 1100.

[0070] In specific implementation, after collecting the readings of the pressure gauge 410 after cyclic loading and completing the detection process, before the staff disassemble the first casing 1000 and the second casing 1100, they will open the pressure relief valve 310 connected to the second casing 1100 to release the high-pressure detection gas in the first casing 1000 and the second casing 1100 until the readings of the pressure gauge 410 are the same as the atmospheric pressure, so as to avoid the safety hazards brought by the high pressure in the pipe.

[0071] Referring to Figure 1As shown, in some embodiments, a first placement hole 110 adapted to the first casing 1000 is formed in the detection platform 100. The first placement hole 110 is used for the first casing 1000 to be inserted into the detection platform 100; further included is a mounting base 500. The mounting base 500 is slidably disposed on the detection platform 100, and a second placement hole 510 adapted to the second casing 1100 is formed in the mounting base 500. The second placement hole 510 is used for the second casing 1100 to be inserted into the detection platform 100.

[0072] Before performing the airtightness detection of the casing, the first casing 1000 is inserted into the first placement hole 110 to fix the first casing 1000 in the circumferential direction, improving the mating strength between the first casing 1000 and the detection platform 100; the same applies to the second casing 1100; meanwhile, the first placement hole 110 and the second placement hole 510 can also seal the free ends of the first casing 1000 and the second casing 1100 respectively, avoiding the influence of air leakage at the free ends of the first casing 1000 and the second casing 1100 on the detection result of the casing airtightness.

[0073] Furthermore, in some embodiments, a coupling 600 is further included. The coupling 600 is used to be sleeved on the joint of the first casing 1000 and the second casing 1100.

[0074] The purpose of setting the coupling 600 is to improve the mating strength between the first casing 1000 and the second casing 1100, avoiding that after the pressurizing assembly 200 injects high-pressure detection gas into the first casing 1000, under the action of gas pressure, the first casing 1000 and the second casing 1100 are disengaged from the mating, resulting in the inability to carry out the airtightness detection operation normally and bringing potential safety hazards.

[0075] Still further, in some embodiments, a pressure-applying assembly 700 is further included. The pressure-applying assembly 700 is installed on the detection platform 100, and the moving end of the pressure-applying assembly 700 abuts against the outer wall of the coupling 600; the controller 420 is electrically connected to the pressure-applying assembly 700 to control the pressure-applying assembly 700 to apply a downward pressure to the coupling 600.

[0076] During the actual oil drilling process, to ensure that the wellbore is within the reservoir, it is necessary to continuously adjust the drilling trajectory of the drill bit, resulting in a complex and highly bent shape of the finally formed wellbore; it is difficult to insert the casing in place in one go. By using the method of lifting and flushing, an impact load is generated on the casing so that the casing can be inserted into the target formation. Therefore, in the above embodiments, the pressure-applying assembly 700 is added. Before the airtightness detection, a downward pressure is applied to the connection between the first casing 1000 and the second casing 1100 to simulate the situation where the casing is subjected to bending loads during the actual insertion process, ensuring the objectivity of the detection result of the casing airtightness.

[0077] Meanwhile, the pressure of the pressing component 700 is concentrated on the outer wall of the collar 600, preventing the pressing component 700 from damaging the surfaces of the first casing 1000 and the second casing 1100, thus affecting the structural stability of the first casing 1000 and the second casing 1100.

[0078] Furthermore, in some embodiments, the pressing component 700 includes a driving rod 710 and a pressing member 720. The driving rod 710 is installed on the detection platform 100, and the controller 420 is electrically connected to the driving rod 710 to control the rotation of the driving rod 710. The pressing member 720 is sleeved on the driving rod 710 and is threadedly connected to the driving rod 710 to drive the pressing member 720 to move up and down.

[0079] Here, the connection between the pressing member 720 and the driving rod 710 is set as a threaded connection. Taking advantage of the characteristics of small outer dimension, simple structure and high precision of the threaded connection, not only the overall structure of the pressing component 700 is more compact and the maintenance is more convenient, but also the lifting movement of the pressing member 720 and the pressure applied to the connection between the first casing 1000 and the second casing 1100 are easier to control, avoiding the situation that the applied pressure value is too small to simulate the bending load on the casing during actual use, or the applied pressure value is too large to damage the surfaces of the first casing 1000 and the second casing 1100. Of course, the staff can also use a gear-rack drive to replace the threaded connection between the pressing member 720 and the driving rod 710, but it will increase the operating cost of the airtightness detection device.

[0080] Refer to Figure 1 As shown, in some embodiments, a pushing member 800 is further included. The pushing member 800 is installed on the detection platform 100, and the moving end of the pushing member 800 abuts against the mounting seat 500. The controller 420 is electrically connected to the pushing member 800 to control the pushing member 800 to push the mounting seat 500 to slide towards the first casing 1000.

[0081] Specifically, the pushing member 800 is set as a hydraulic cylinder. Before the airtightness detection, the hydraulic cylinder applies a thrust to the second casing 1100 in the direction towards the first casing 1000 to simulate the situation of the casing being subjected to an axial load during actual lowering, ensuring the objectivity of the airtightness detection result of the casing.

[0082] Meanwhile, since the pressing component 700 has applied a downward pressure to the connection between the first sleeve 1000 and the second sleeve 1100 in advance, the connection between the first sleeve 1000 and the second sleeve 1100 is slightly bent downward. After the hydraulic cylinder applies a thrust to the second sleeve 1100, the first sleeve 1000 and the second sleeve 1100 as a whole will only have a tendency to bend vertically downward. Of course, the staff can also flexibly adjust the specific structure of the pushing member 800 according to the actual detection requirements, which will not be elaborated here one by one.

[0083] Referring to Figure 1 As shown, in some embodiments, a displacement sensor 900 is further included. The displacement sensor 900 is used to be installed on the outer walls of the first sleeve 1000 and the second sleeve 1100 to monitor the shape changes of the first sleeve 1000 and the second sleeve 1100. The controller 420 is electrically connected to the displacement sensor 900 to collect the measurement data of the displacement sensor 900.

[0084] In specific implementation, before the first sleeve 1000 and the second sleeve 1100 are fixed and airtightness is detected, the controller 420 will control the pressing component 700 to apply a downward pressure to the connection between the first sleeve 1000 and the second sleeve 1100 to simulate the situation where the sleeve is subjected to a bending load during actual use; control the pushing member 800 to apply a thrust to the second sleeve 1100 in the direction close to the first sleeve 1000 to simulate the situation where the sleeve is subjected to an axial load during actual lowering, and collect the measurement data of the displacement sensor 900, fit the displacement data into displacement curves in the horizontal and vertical directions, and then calculate the bending dogleg degree at the connection between the first sleeve 1000 and the second sleeve 1100 according to relevant formulas; repeat the above operations to increase the thrust applied to the second sleeve 1100 until the calculated bending degree is the same as the preset bending degree, and stop applying the above pressure and the above thrust.

[0085] Further, referring to Figure 1 As shown, in some embodiments, the number of the displacement sensors 900 is set to be multiple, and the multiple displacement sensors 900 are respectively arranged at intervals along the extending directions of the first sleeve 1000 and the second sleeve 1100.

[0086] In the above embodiments, the number of the displacement sensors is set to six, and each displacement sensor 900 is evenly distributed on the first sleeve 1000 and the second sleeve 1100 and arranged at intervals to ensure that the shape changes at various positions on the first sleeve 1000 and the second sleeve 1100 can be obtained. Of course, the number of the displacement sensors can be set to four or eight, or can be centrally arranged at the connection between the first sleeve 1000 and the second sleeve 1100. The staff can flexibly adjust according to the actual detection requirements, which will not be elaborated here one by one.

[0087] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the disclosure of the embodiments of the present application can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed in the embodiments of the present application can be achieved, and no limitations are imposed herein.

[0088] The above specific embodiments do not constitute a limitation on the protection scope of the embodiments of the present application. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the principles of the embodiments of the present application shall be included within the protection scope of the embodiments of the present application.

Claims

1. A threaded joint airtightness detection device under the compound loading condition of a casing string, characterized in that Comprising: A detection platform (100) for fixing a first sleeve (1000) and a second sleeve (1100), and making the end face of the first sleeve (1000) fit with the end face of the second sleeve (1100) to form a gas channel; A pressurizing assembly (200) installed on the detection platform (100) and used for communicating with the first sleeve (1000) to introduce gas into the first sleeve (1000); A pressure relief assembly (300) installed on the detection platform (100) and used for communicating with the second sleeve (1100) to release the gas flowing into the second sleeve (1100); A measurement assembly (400) includes a barometer (410) and a controller (420). The barometer (410) is used to be installed on the outer wall of the second sleeve (1100) to monitor the air pressure change in the second sleeve (1100); the controller (420) is electrically connected to the barometer (410) to collect the measurement data of the barometer (410).

2. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 1, wherein, The pressurizing assembly (200) includes a gas pump (210). The gas pump (210) is used to communicate with the air inlet of the first sleeve (1000) through a first conduit (220); the controller (420) is electrically connected to the gas pump (210) to control the gas pump (210) to introduce the gas into the first sleeve (1000).

3. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 1, characterized in that, The pressure relief assembly includes a pressure relief valve (310). The pressure relief valve (310) is used to communicate with the air outlet of the second sleeve (1100) through a second conduit (320) to release the gas from the second sleeve.

4. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to any one of claims 1 to 3, characterized in that, A first placement hole (110) adapted to the first sleeve (1000) is formed on the detection platform (100). The first placement hole (110) is used for the first sleeve (1000) to be inserted into the detection platform (100); It further includes a mounting seat (500). The mounting seat (500) is slidably arranged on the detection platform (100), and a second placement hole (510) adapted to the second sleeve (1100) is formed on the mounting seat (500). The second placement hole (510) is used for the second sleeve (1100) to be inserted into the detection platform (100).

5. The airtightness detection device for the threaded connection under the compound loading condition of the casing string according to claim 4, characterized in that It further includes a coupling (600). The coupling (600) is used to be sleeved on the joint of the first sleeve (1000) and the second sleeve (1100).

6. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 5, characterized in that, It further includes a pressing assembly (700). The pressing assembly (700) is installed on the detection platform (100), and the moving end of the pressing assembly (700) abuts against the outer wall of the coupling (600); the controller (420) is electrically connected to the pressing assembly (700) to control the pressing assembly (700) to apply a downward pressure to the coupling (600).

7. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 6, wherein The pressure - applying assembly (700) includes a driving rod (710) and a pressure - applying member (720). The driving rod (710) is installed on the detection platform (100), and the controller (420) is electrically connected to the driving rod (710) to control the rotation of the driving rod (710). The pressure - applying member (720) is sleeved on the driving rod (710) and is thread - connected to the driving rod (710) to drive the pressure - applying member (720) to move up and down.

8. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 4, characterized in that, It further includes a pushing member (800). The pushing member (800) is installed on the detection platform (100), and the moving end of the pushing member (800) abuts against the mounting seat (500). The controller (420) is electrically connected to the pushing member (800) to control the pushing member (800) to push the mounting seat (500) to slide in the direction close to the first sleeve (1000).

9. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to any one of claims 1 to 3, characterized in that, It further includes a displacement sensor (900). The displacement sensor (900) is used to be installed on the outer walls of the first sleeve (1000) and the second sleeve (1100) to monitor the shape changes of the first sleeve (1000) and the second sleeve (1100). The controller (420) is electrically connected to the displacement sensor (900) to collect the measurement data of the displacement sensor (900).

10. The airtightness detection device for the thread connection under the compound loading condition of the casing string according to claim 9, wherein, The number of the displacement sensors (900) is set to be multiple, and the multiple displacement sensors (900) are respectively arranged at intervals along the extending directions of the first sleeve (1000) and the second sleeve (1100).

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