Pressure-torsion combined loading test bed and method for flexible drill rod in bending state

Abstract

The invention relates to the technical field of mechanical tests of flexible drill rods, in particular to a pressure-torsion composite loading test bench and method for a flexible drill rod in a bending state, and the test bench comprises a base, a pressure-torsion composite device arranged at the top of the base, a supporting seat and a swing angle device; the supporting seat is arranged in the middle of the top of the base and used for fixing the middle of a flexible drill rod short section. The pressure-torsion composite device and the swing angle device are arranged on the two sides of the supporting base respectively and connected with one end of the flexible drill rod short section respectively. The pressure-torsion composite device is used for providing a pressure-torsion composite load for the flexible drill pipe nipple; and the angle swinging device is used for swinging the flexible drill rod short section at a preset angle. According to the invention, the comprehensive performance test of the flexible drill rod under a complex working condition is realized; the device is reasonable in structure and easy and convenient to operate, the actual working conditions of the drill rod can be accurately simulated, and powerful technical support is provided for design optimization, performance evaluation and safe use of the drill rod.

Description

Technical Field

[0001] The invention relates to the technical field of flexible drill rod mechanical testing, in particular to a compression-torsion composite loading test bench and method for a flexible drill rod in a bent state. Background Art

[0002] In the field of oil and gas field development, improving the production and recovery of single wells is a continuous goal, and ultra-short radius multi-branch radial horizontal well technology is one of the key means to achieve this goal. In this technology, flexible drill pipe is the core tool, and its performance directly determines the success and efficiency of drilling operations. The flexible drill pipe has a unique design and is composed of multiple drill pipe short sections connected end to end. Each short section has a certain bending ability. Through continuous bending, a smooth transition from vertical to horizontal sections is formed, thereby supporting the drilling of ultra-short radius horizontal wells. This design enables the flexible drill pipe to penetrate into complex formations, significantly improving the mining range and efficiency of oil wells.

[0003] During the drilling process, the flexible drill pipe is located at the bottom of the drill bit assembly, directly connected to the drill bit or flexible drill bit, and undertakes the important task of transmitting drilling pressure, torque and pressure. However, due to its unique structure and working environment, the flexible drill pipe faces extremely high mechanical stress challenges. During the drilling process, the drill pipe needs to withstand the huge pressure from the drill bit and the rotational torque of the drilling rig at the same time. This double load can easily lead to serious problems such as drill pipe fatigue, fracture or seal failure, which in turn causes safety accidents and affects the smooth progress of drilling operations.

[0004] In order to ensure the reliability and durability of flexible drill pipes under complex working conditions, strict mechanical property verification must be carried out during the research and development process. However, the composite loading test equipment currently available on the market mostly performs loading tests on flexible drill pipes in straight or linear states with a single force (such as simple pressure, tension or torque), which cannot accurately simulate the bending state of the flexible drill pipe during the actual drilling process and the complex working conditions of being subjected to a composite compression and torsion load at the same time. The limitations of this test method make it difficult for the test results to fully reflect the true mechanical properties of the flexible drill pipe, and it is also impossible to provide an accurate verification basis for numerical simulations. Summary of the invention

[0005] The purpose of the present invention is to provide a compression-torsion composite loading test bench and method for a flexible drill pipe in a bent state in order to solve at least one of the above-mentioned technical problems, which can truly simulate the stress conditions of the flexible drill pipe in the actual drilling process, and provide more accurate data support for the mechanical property evaluation and life prediction of the flexible drill pipe, thereby promoting the further development and application of ultra-short radius multi-branch radial horizontal well technology.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A compression-torsion composite loading test bench in a flexible drill rod bending state, comprising: a base, a compression-torsion composite device arranged on the top of the base, a support seat, and a swing angle device;

[0008] The support seat is arranged in the middle of the top of the base, and the support seat is used to fix the middle part of the flexible drill pipe short section to be tested;

[0009] The compression-torsion composite device and the swing angle device are respectively arranged on both sides of the support seat, and are respectively connected to one end of the flexible drill rod short section;

[0010] The compression-torsion composite device is used to provide a compression-torsion composite load for the flexible drill pipe short section; the swing angle device is used to swing the flexible drill pipe short section at a preset angle.

[0011] Furthermore, a through hole is provided in the middle of the top of the support seat, and the flexible drill rod short section is slidably connected to the support seat through the through hole.

[0012] Furthermore, the stand further comprises: a T-shaped guide rail fixedly connected to the top of the base;

[0013] The compression-twist composite device comprises: a compression-action support platform fixedly connected to the base, a torsion-action housing with a bottom slidably connected to the T-shaped guide rail, and a compression actuator;

[0014] The torsion action casing is provided with a torsion action casing side ear; one end of the pressing actuator is connected to the pressing action support platform, and the other end is connected to the torsion action casing side ear; the force applied by the pressing actuator to the torsion action casing side ear drives the torsion action casing to slide along the T-shaped guide rail.

[0015] Furthermore, a torsion actuator is fixed inside the torsion action housing, the extended shaft of the torsion actuator is connected to the transmission shaft through a torsion clamp, a thrust bearing is installed on the transmission shaft, the thrust bearing is connected to a pressure action clamp, and the pressure action clamp is fixedly connected to the flexible drill pipe short section.

[0016] Further, the thrust bearing is connected to the press-action fixture via a bearing seat;

[0017] The thrust bearing comprises a stator, a roller and a rotor. The stator is at least partially fixed in the torsion action housing. The stator is connected to the rotor through the roller. The rotor is in close contact with the action fixture.

[0018] Furthermore, the stand further comprises: an arc-shaped guide rail fixedly connected to the top of the base;

[0019] The swing angle device comprises: a lower end fixture slidably connected to the arc-shaped guide rail, and guide rail fixtures fixed to the top of the arc-shaped guide rail and respectively located on both sides of the lower end fixture;

[0020] An upper end fixture is correspondingly arranged on the top of the lower end fixture, and the lower end fixture is connected to the upper end fixture to fix the end of the flexible drill rod short section.

[0021] Furthermore, the angle swing device further comprises: a square rod clamp for clamping the end of the flexible drill rod short section;

[0022] Grooves are provided at corresponding positions of the upper portion of the lower end fixture and the lower portion of the upper end fixture, and the square rod fixture is installed in a cavity formed by merging the grooves of the lower end fixture and the upper end fixture.

[0023] Furthermore, the position of the guide rail clamp on the arc-shaped guide rail is adjustable, and the lower end clamp slides between the two guide rail clamps.

[0024] A method for testing a compression-torsion composite loading in a flexible drill pipe under a bent state, applied to any of the above-mentioned compression-torsion composite loading test benches under a bent state of a flexible drill pipe, comprises the following steps:

[0025] Place the flexible drill pipe short section in the through hole of the support seat;

[0026] The two ends of the flexible drill pipe short section are respectively connected to the compression-torsion composite device and the swing angle device;

[0027] The compression-torsion composite device applies a torsional load and a compressive load to the flexible drill pipe short section to achieve compression-torsion composite loading; and the swing angle device drives the flexible drill pipe short section to swing at a preset angle.

[0028] Furthermore, the stand comprises an arc-shaped guide rail fixedly connected to the top of the base; the swing angle device comprises a guide rail clamp and a lower end clamp; the lower end clamp is slidably connected to the arc-shaped guide rail; the guide rail clamp (3) is arranged on both sides of the lower end clamp and is located at the top of the arc-shaped guide rail;

[0029] The preset angle is adjusted by adjusting the position of the guide rail clamp on the arc-shaped guide rail.

[0030] The beneficial effects of the present invention are:

[0031] The comprehensive test bench designed by the present invention is not limited to straight rods, but also realizes the compression-torsion composite loading experiment of two flexible drill rod short sections in a bent state, which greatly expands the scope of experimental application.

[0032] The invention has flexible and diverse applicable objects. In addition to the flexible drill pipe short section, it can also be applied to a hinge-connected two-straight rod mechanism with a similar structure, thereby enhancing the versatility and practicality of the equipment.

[0033] The swing angle device design of the present invention allows the flexible drill pipe short section to be flexibly swung to different angles on the arc guide rail, and then the compression-torsion composite loading test is performed under different bending states, effectively identifying the bending form with the weakest bearing capacity of the drill pipe.

[0034] In the compression-torsion composite loading device of the present invention, a thrust bearing is innovatively introduced, which not only ensures that the flexible drill pipe short section can withstand pressure load or torsional load alone, but also realizes the application of compression-torsion composite load, providing strong support for comprehensive evaluation of drill pipe performance.

[0035] The present invention realizes accurate compression-torsion composite loading test of flexible drill pipe under various bending states, provides reliable data support for evaluating its mechanical properties and predicting its life, and promotes the development of ultra-short radius multi-branch radial horizontal well technology. At the same time, through the flexible swing angle device and compression-torsion composite loading design, the present invention can simulate the working environment under different bending angles and load conditions, accurately locate the limit state of the bearing capacity of the flexible drill pipe, and provide an important reference for drill pipe design optimization and field application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of a compression-torsion composite loading test bench in a bending state of a flexible drill rod according to an embodiment of the present invention;

[0037] Figure 2 A cross-sectional view of a compression-twist composite device according to an embodiment of the present invention;

[0038] Figure 3 A partial cross-sectional view of a thrust bearing installation according to an embodiment of the present invention;

[0039] Figure 4 A partial schematic diagram of a swing angle device according to an embodiment of the present invention;

[0040] Figure 5 It is a partial connection schematic diagram of the swing angle device according to one embodiment of the present invention;

[0041] Figure 6 The present invention is a flowchart of a method for testing a compression-torsion composite loading of a flexible drill rod in a bent state according to an embodiment of the present invention.

[0042] Among them, 1. base, 2. arc guide rail, 3. guide rail clamp, 4. lower end clamp, 5. upper end clamp, 6. flexible drill pipe short section, 601. square rod clamp, 7. press action clamp, 8. thrust bearing, 801. stator, 802. roller, 803. rotor, 9. torsion action housing, 10. T-shaped guide rail, 11. press action device, 12. press action support platform, 13. support seat, 14. torsion action housing side ear, 15. transmission shaft, 16. bearing seat, 17. torsion clamp, 18. torsion actuator. DETAILED DESCRIPTION

[0043] The content of the present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only to enable those skilled in the art to better understand and thus implement the content of the present invention, rather than implying any limitation on the scope of the present invention.

[0044] As used herein, the term “including” and variations thereof are to be interpreted as open-ended terms meaning “including, but not limited to.” The term “based on” is to be interpreted as “based, at least in part, on.” The terms “one embodiment” and “an embodiment” are to be interpreted as “at least one embodiment.”

[0045] Embodiment 1

[0046] Figure 1 This is a schematic diagram of the overall structure of a compression-torsion composite loading test bench in a bending state of a flexible drill rod according to an embodiment of the present invention. Figure 1 As shown, according to one embodiment of the present invention, a compression-torsion composite loading test bench in a flexible drill rod bending state comprises: a base 1, a compression-torsion composite device arranged on the top of the base 1, a support seat 13, and a swing angle device;

[0047] The support seat 13 is arranged in the middle of the top of the base 1, and the support seat 13 is used to fix the middle part of the flexible drill pipe short section 6 to be tested;

[0048] The compression-torsion composite device and the swing angle device are respectively arranged on both sides of the support seat 13 and are respectively connected to one end of the flexible drill pipe short section 6;

[0049] The compression-torsion composite device is used to provide a compression-torsion composite load for the flexible drill pipe short section 6; the swing angle device is used to swing the flexible drill pipe short section 6 at a preset angle.

[0050] In this embodiment, the compression-torsion composite loading test bench for the flexible drill pipe in the bending state includes a base 1, which serves as the basic support structure of the entire test bench and stably carries all components. The support seat 13 is accurately installed at the top center of the base 1, and its main function is to fix the middle part of the flexible drill pipe short section 6 to be tested, ensuring that the flexible drill pipe short section 6 can be stably in the test state during the test. The compression-torsion composite device is arranged on one side of the support seat 13, and is tightly connected to one end of the flexible drill pipe short section 6 through a special clamp or a direct connection. The compression-torsion composite device integrates pressure and torque loading functions, which can simulate the complex load conditions that the drill pipe is subjected to under actual working conditions, and provide accurate compression-torsion composite loads for the flexible drill pipe short section 6 to test its strength, stiffness and durability.

[0051] The swing angle device provided on the other side of the support seat 13 is connected to the other end of the flexible drill pipe short section 6 through a flexible mechanical structure. The swing angle device can accurately control the swing of the flexible drill pipe short section 6 at a preset angle in the plane according to the test requirements, thereby simulating the working conditions of the drill pipe in different bending states. The design of the swing angle device not only increases the flexibility of the test, but also greatly improves the comprehensiveness and accuracy of the test results.

[0052] The present invention realizes comprehensive performance testing of flexible drill pipes under complex working conditions by integrating the two functions of compression-torsion composite loading and swing angle control. Its structural design is reasonable, the operation is simple, and it can accurately simulate the actual working conditions of the drill pipe, providing strong technical support for the design optimization, performance evaluation and safe use of the drill pipe. Through the testing of this test bench, the performance reliability of the flexible drill pipe can be significantly improved, the use risk can be reduced, and the further development of drilling technology can be promoted.

[0053] According to one embodiment of the present invention, a through hole is provided in the middle of the top of the support seat 13, and the flexible drill rod short section 6 is slidably connected to the support seat 13 through the through hole.

[0054] In this real-time method, a through hole is carefully designed in the center of the top of the support seat 13. The shape and size of this through hole are precisely calculated to ensure a perfect match with the outer diameter of the flexible drill pipe short section 6. The flexible drill pipe short section 6 is slidably connected to the support seat 13 through this through hole, that is, the drill pipe short section can move freely within a certain range along the axial direction of the through hole during the test. This design not only simplifies the structure of the test bench, but also ensures that the flexible drill pipe short section 6 can move smoothly along the predetermined path during the test, thereby more realistically simulating its dynamic characteristics in the actual working environment. During the test, the support seat 13 is firmly fixed on the base 1 to provide stable support for the middle part of the flexible drill pipe short section 6. The compression-torsion composite device and the swing angle device act on the two ends of the drill pipe short section respectively. The former applies a compression-torsion composite load to test the bearing capacity and deformation characteristics of the drill pipe, and the latter simulates the bending state of the drill pipe by swinging at a preset angle. Since the flexible drill pipe short section 6 and the support seat 13 are slidably connected through a through hole, it can complete complex mechanical properties tests under the synergistic effect of the two devices.

[0055] The present invention realizes a smooth sliding connection between the flexible drill pipe short section and the base, which not only simplifies the structure of the test bench and improves the flexibility and accuracy of the test, but also ensures that the flexible drill pipe short section can move freely along a predetermined path during the test, thereby more comprehensively simulating its dynamic characteristics in an actual working environment.

[0056] Figure 2 FIG. 2 is a cross-sectional view of a compression-twist composite device according to an embodiment of the present invention. Figure 2 As shown, according to one embodiment of the present invention, the stand further comprises: a T-shaped guide rail 10 fixedly connected to the top of the base 1;

[0057] The compression and twisting composite device comprises: a compression action support platform 12 fixedly connected to the base 1, a twisting action housing 9 whose bottom is slidably connected to the T-shaped guide rail 10, and a compression actuator 11;

[0058] A torsion action casing side ear 14 is provided on the torsion action casing 9; one end of the pressing actuator 11 is connected to the pressing action support platform 12, and the other end is connected to the torsion action casing side ear 14; the force exerted by the pressing actuator 11 on the torsion action casing side ear 14 drives the torsion action casing 9 to slide along the T-shaped guide rail 10.

[0059] In this embodiment, the T-shaped guide rail 10 is firmly fixed on the top of the base 1, providing accurate guidance and stable support for the key components in the compression-twist composite device. The compression support platform 12, as the basic part of the compression-twist composite device, is also closely connected to the base 1, ensuring the stability of the entire device. The torsion housing 9 is one of the core components of the compression-twist composite device, and its bottom is slidably connected to the T-shaped guide rail 10 through a specific design. This design enables the torsion housing 9 to perform linear motion under the guidance of the T-shaped guide rail 10, thereby achieving accurate loading of the flexible drill rod short section 6. A torsion housing side ear 14 is provided on the torsion housing 9 as a key point for force transmission. The pressure actuator 11 plays the role of a power source, one end of which is connected to the compression support platform 12, and the other end is closely connected to the torsion housing side ear 14. When the pressure actuator 11 is started, it will push the torsion housing 9 to slide along the T-shaped guide rail 10 through the force acting on the torsion housing side ear 14.

[0060] The present invention realizes precise compression-torsion composite loading of the flexible drill pipe short section by introducing a T-shaped guide rail and a combination of a compression actuator and a torsion action housing; the guiding effect of the T-shaped guide rail ensures stability and accuracy during the loading process, while the compression actuator provides a reliable power source, allowing the torsion action housing to slide along a predetermined trajectory. The present invention not only improves the accuracy and reliability of the test, but also provides a more comprehensive and realistic simulation environment for the performance evaluation of the flexible drill pipe under different working conditions. Through the implementation of this technical solution, the load-bearing capacity, deformation characteristics and durability of the flexible drill pipe can be more effectively evaluated, providing strong support for the design and optimization of drilling projects.

[0061] According to one embodiment of the present invention, a torsion actuator 18 is fixed inside the torsion action housing 9, and the outer extension shaft of the torsion actuator 18 is connected to the transmission shaft 15 through a torsion clamp 17. A thrust bearing 8 is installed on the transmission shaft 15, and the thrust bearing 8 is connected to the pressure action clamp 7, and the pressure action clamp 7 is fixedly connected to the flexible drill pipe short section 6.

[0062] Preferably, the thrust bearing 8 is connected to the press-action fixture 7 via a bearing seat 16;

[0063] Figure 3 FIG. 1 is a partial cross-sectional view of a thrust bearing installation according to an embodiment of the present invention. Figure 3 As shown, the thrust bearing 8 includes a stator 801 , a roller 802 , and a rotor 803 . The stator 801 is at least partially fixed in the torsion action housing 9 . The stator 801 is connected to the rotor 803 through the roller 802 . The rotor 803 is in close contact with the action fixture 7 .

[0064] In this embodiment, the torsion action housing 9 not only serves as a sliding carrier, but also carries the key component of the torsion actuator 18. The torsion actuator 18 is firmly fixed inside the torsion action housing 9, and its extended shaft is tightly connected to the transmission shaft 15 through the torsion clamp 17. This connection method ensures that the torsion force generated by the torsion actuator 18 can be efficiently and accurately transmitted to the transmission shaft 15. The transmission shaft 15 serves as a bridge for force transmission, and a thrust bearing 8 is installed on it. The thrust bearing 8 is connected to the action clamp 7 through the bearing seat 16, and this connection is more stable. The action clamp 7 is directly and fixedly connected to the flexible drill pipe short section 6, so that the entire torsion loading system can accurately act on the flexible drill pipe short section 6.

[0065] The thrust bearing 8 includes a stator 801, a roller 802 and a rotor 803. The stator 801 is at least partially fixed in the torsion action housing 9 to provide stable support for the entire bearing. The roller 802 acts as an intermediary to reduce the friction between the stator 801 and the rotor 803 through rolling contact, thereby improving the efficiency and stability of the transmission. The rotor 803 is in close contact with the action fixture 7 to transmit the torsion force from the transmission shaft 15 to the flexible drill pipe short section 6.

[0066] The present invention constructs an efficient and stable torsion loading system by introducing a thrust bearing and a torsion actuator; the thrust bearing improves the load-bearing capacity and stability of the system; the tight connection between the torsion actuator and the transmission shaft, the thrust bearing and the action fixture ensures that the torsion force can be accurately and efficiently transmitted to the flexible drill pipe short section. The present invention not only improves the accuracy and reliability of the test, but also provides a more comprehensive and realistic simulation environment for the performance evaluation of the flexible drill pipe under different working conditions.

[0067] Figure 4 FIG. 1 is a partial schematic diagram of a swing angle device according to an embodiment of the present invention. Figure 4 As shown, according to one embodiment of the present invention, the stand further comprises: an arc-shaped guide rail 2 fixedly connected to the top of the base 1;

[0068] The swing angle device comprises: a lower end fixture 4 slidably connected to the arc-shaped guide rail 2, and guide rail fixtures 3 fixed to the top of the arc-shaped guide rail 2 and respectively located on both sides of the lower end fixture 4;

[0069] An upper end fixture 5 is correspondingly arranged on the top of the lower end fixture 4 , and the end of the flexible drill pipe short section 6 is fixed after the lower end fixture 4 is connected to the upper end fixture 5 .

[0070] Figure 5 FIG. 1 is a partial connection diagram of a swing angle device according to an embodiment of the present invention. Figure 5 As shown, preferably, the swing angle device further comprises a square rod clamp 601 for clamping the end of the flexible drill rod short section 6;

[0071] Grooves are provided at corresponding positions of the upper portion of the lower end fixture 4 and the lower portion of the upper end fixture 5 , and the square rod fixture 601 is installed in the cavity formed by merging the grooves of the upper portion of the lower end fixture 4 and the lower portion of the upper end fixture 5 .

[0072] In this embodiment, the design of the stand is further improved, and an arc guide rail 2 is introduced as a key component, which is firmly fixed to the top of the base 1, providing a precise sliding track for the swing angle device. The swing angle device is mainly composed of a lower end clamp 4, a guide rail clamp 3 and an upper end clamp 5. The lower end clamp 4 is tightly combined with the arc guide rail 2 by a sliding connection, ensuring that it can move smoothly along a preset arc path during the swinging process. The guide rail clamp 3 is fixed to the top of the arc guide rail 2, and is located on both sides of the lower end clamp 4, which plays a role in positioning and stabilizing the lower end clamp 4. The sliding of the lower end clamp 4 is located between the two guide rail clamps 3.

[0073] The designs of the lower end fixture 4 and the upper end fixture 5 correspond to each other, and they work together to fix the end of the flexible drill pipe short section 6. The bottom of the lower end fixture 4 is fixed on the arc guide rail 2, and the flexible drill pipe short section 6 is placed between the upper end fixture 5 and the lower end fixture 4, and they are tightly locked using threaded connection or other fastening methods, so that the end of the flexible drill pipe short section 6 is firmly fixed.

[0074] In order to further enhance the stability and reliability of fixation, a square rod clamp 601 is also introduced. The square rod clamp 601 is installed in the cavity formed by merging the upper part of the lower end clamp 4 and the lower groove of the upper end clamp 5. By clamping the end of the flexible drill rod short section 6, a more stable fixing effect is achieved.

[0075] The present invention provides a stable and reliable platform for adjusting the swing angle of the flexible drill pipe short section by introducing an arc guide rail and a swing angle device; the arc guide rail ensures the precise sliding of the swing angle device, and the guide rail clamp ensures the stability of the lower end clamp during the sliding process; the synergistic effect of the lower end clamp, the upper end clamp and the square rod clamp realizes the firm fixation of the end of the flexible drill pipe short section, laying a solid foundation for subsequent swing angle adjustment and performance testing.

[0076] According to one embodiment of the present invention, the position of the guide rail clamp 3 on the arc-shaped guide rail 2 is adjustable, and the lower end clamp 4 slides between the two guide rail clamps 3 .

[0077] In this embodiment, the arc-shaped guide rail 2 provides a smooth and precise moving path. The guide rail clamp 3 can slide freely on the arc-shaped guide rail 2 and lock at any position; this adjustability allows the user to flexibly adjust the position of the clamp according to specific task requirements to adapt to workpieces of different sizes or shapes. The lower end clamp 4 is designed between the two guide rail clamps 3 and can slide along the interval defined by the two guide rail clamps 3 to meet more complex clamping requirements.

[0078] The present invention simplifies the complex process of positioning and clamping the workpiece, improves production efficiency, and ensures the stability and accuracy of the workpiece during processing or transmission through precise position adjustment capabilities.

[0079] The test bench for compression-torsion composite loading under the bending state of the flexible drill pipe of the present invention realizes precise compression-torsion composite loading and swing angle adjustment of the flexible drill pipe short section by integrating the base, compression-torsion composite device, support seat, swing angle device and slidingly connected T-shaped guide rails and arc guide rails. The present invention has reasonable structural design and simple operation, and can efficiently and accurately simulate the complex load conditions that the drill pipe is subjected to under actual working conditions, as well as the working conditions under different bending states. Through the introduction of thrust bearings and torsion actuators, a stable and efficient torsion loading system is constructed to ensure the precise transmission of torsional force. In addition, the adjustable guide rail fixture of the swing angle device further enhances the flexibility and adaptability of the test bench. On the whole, the present invention significantly improves the comprehensiveness, accuracy and reliability of the performance test of the flexible drill pipe, provides strong technical support for the design optimization, performance evaluation and safe use of the drill pipe, and effectively promotes the development of drilling technology.

[0080] Embodiment 2

[0081] like Figure 1 As shown, according to one embodiment of the present invention, a compression-torsion composite loading test bench for a flexible drill rod in a bending state includes a base 1, a T-shaped guide rail 10 is fixed to the right end of the base 1, and the T-shaped guide rail 10 is slidably connected to the compression-torsion composite device; the compression-torsion composite device is connected to the right end of the flexible drill rod short section 6 through a pressure-action clamp 7, and the middle part of the flexible drill rod short section 6 is slidably connected to the support seat 13 of the base 1, and the left end of the flexible drill rod short section 6 is a swing angle device, which is connected to the flexible drill rod short section 6 through a square rod clamp 601, and is slidably connected to the arc guide rail 2 on the base 1 through the lower end clamp 4.

[0082] The base 1 is fixed with a T-shaped guide rail 10 which is slidably connected with the compression-torsion composite device, a curved guide rail 2 which is slidably connected with the swing angle device, and a support seat 13 which is slidably connected with the flexible drill pipe short section 6.

[0083] like Figure 2-3As shown, the compression-torsion composite loading device includes two compression actuators 11, a compression support platform 12 is fixed on the base 1, and is also fixed to the two compression actuators 11 respectively, the compression actuator 11 acts on the side ears 14 of the torsion action housing, the torsion action housing 9 and the T-shaped guide rail 10 form a sliding connection, a torsion actuator 18 is fixed in the torsion action housing 9, the extension shaft of the torsion actuator 18 is connected to the transmission shaft 15 through the torsion clamp 17, and the transmission shaft 15 is equipped with a thrust bearing 8, and the thrust bearing 8 is connected to the compression action clamp through the bearing seat 16. 7 connection; wherein the thrust bearing 8 comprises a stator 801, a roller 802, and a rotor 803, wherein the stator 801 is fixed in the housing of the torsion actuator 18, the stator 801 is connected to the rotor 803 through the roller 802, the rotor 803 is in close contact with the pressing action fixture 7, the pressing action fixture 7 is connected to the transmission shaft 15 and the flexible drill pipe short section 6, one end of the pressing action fixture 7 is in close contact with the end surface of the rotor 803 of the thrust bearing 8, and when the flexible drill pipe short section 6 rotates, the pressing action fixture 7 rotates together with the rotor 803 of the thrust bearing 8;

[0084] like Figure 4-5 As shown, the swing angle device includes a square rod fixture 601 that clamps the end of the flexible drill rod short section 6, which can be installed in the corresponding end fixture (lower end fixture 4 and upper end fixture 5) cavity, the upper end fixture 5 and the lower end fixture 4 are connected by threads, the lower end fixture 4 is slidably connected with the arc guide rail 2, and is in contact with the guide rail fixture 3, and the guide rail fixture 3 is connected to the base 1 by threads;

[0085] The compression-torsion composite loading device can provide a compression-torsion composite load to the flexible drill rod short section 6 ; the swing angle device can swing the flexible drill rod short section 6 to a certain angle and fix it on the arc guide rail 2 .

[0086] The present invention can not only perform a compression-torsion composite loading test on a straight rod, but also achieves a breakthrough compression-torsion composite loading test on two flexible drill rod short sections in a bent state, greatly broadening the scope of experimental application.

[0087] The present invention is not limited to flexible drill pipe short sections, but can also be flexibly applied to hinge-connected two-straight rod mechanisms of similar structures, demonstrating its wide compatibility with experimental objects and high flexibility.

[0088] The present invention can accurately control the swing angle of the flexible drill pipe short section on the arc guide rail through an integrated swing angle device, so as to carry out compression-torsion composite loading experiments under different bending states, accurately locate and reveal the bending form with the weakest bearing capacity of the flexible drill pipe short section.

[0089] The compression-torsion composite loading device of the present invention, combined with the ingenious application of the thrust bearing, not only supports the flexible drill pipe short section to bear pressure or torque loads alone, but also realizes the application of compression-torsion composite loads, providing a powerful tool for in-depth research on the behavior of materials under complex stress states, improving the diversity and depth of experiments, and laying a solid foundation for the comprehensive evaluation of the mechanical properties of materials.

[0090] Embodiment 3

[0091] Figure 6 This is a flow chart of a method for testing the compression-torsion composite loading of a flexible drill pipe under bending conditions in one embodiment of the present invention. Figure 6 As shown, according to one embodiment of the present invention, a compression-torsion composite loading test method of a flexible drill rod in a bent state is applied to a compression-torsion composite loading test bench of a flexible drill rod in a bent state of the present invention, comprising the following steps:

[0092] Step 1: Place the flexible drill pipe short section 6 in the through hole of the support seat 13;

[0093] A through hole is provided on the top of the support seat 13, and the flexible drill rod short section 6 is slidably connected to the support seat 13 through this through hole. The support seat 13 is located directly in front of the compression-torsion composite device and is in the same straight line as the arc guide rail 2, thereby ensuring that the flexible drill rod short section 6 can move smoothly along the predetermined path during testing.

[0094] Step 2: Both ends of the flexible drill pipe short section 6 are connected to the compression-torsion composite device and the swing angle device respectively;

[0095] The compression-torsion composite device is connected to the right end of the flexible drill pipe short section 6 through a compression action clamp 7, and the swing angle device is connected to the left end of the flexible drill pipe short section 6 through a square rod clamp 601.

[0096] Step three, applying a torsional load and a compressive load to the flexible drill pipe short section 6 through the compression-torsion composite device to achieve compression-torsion composite loading; and driving the flexible drill pipe short section 6 to swing at a preset angle through the swing angle device.

[0097] Preferably, the preset angle is adjusted by adjusting the position of the guide rail clamp 3 on the arc-shaped guide rail 2 .

[0098] The force generated by the pressure actuator 11 acts on the side ear 14 of the torsion action housing, and the torsion action housing 9 slides on the T-shaped guide rail 10; the torsion force generated by the torsion actuator 18 is transmitted to the flexible drill pipe short section 6 through the torsion clamp 17, the transmission shaft 15, the thrust bearing 8, and the pressure action clamp 7 in sequence.

[0099] The preset angle is set according to the experimental requirements, and the positions of the two guide rail clamps 3 on the arc guide rail 2 are adjusted according to the test requirements, and the lower end clamp 4 slides between the two guide rail clamps 3 along the arc guide rail 2.

[0100] In this embodiment, the flexible drill pipe short section 6 is first placed in the through hole of the support seat 13 to achieve a sliding connection and ensure that it moves along a predetermined path. Then, the two ends of the flexible drill pipe short section 6 are respectively connected to the compression-torsion composite device and the swing angle device. The pressure actuator 11 applies force to the torsion action housing side ear 14 to achieve sliding along the T-shaped guide rail and compression-torsion composite loading of the flexible drill pipe short section 6. The swing angle device is used to adjust the position of the guide rail clamp 3 on the arc guide rail 2, and the lower end clamp 4 drives the flexible drill pipe short section 6 to swing at a preset angle to complete the entire test process.

[0101] The test method of the present invention effectively simulates the complex working conditions of the flexible drill pipe in actual applications through precise compression-torsion composite loading and angular swing; the method not only improves the accuracy and repeatability of the test, but also realizes a comprehensive evaluation of the drill pipe performance through a specific connection and adjustment mechanism.

[0102] Embodiment 4

[0103] like Figure 6 As shown, according to one embodiment of the present invention, a compression-torsion composite loading test method of a flexible drill rod in a bent state is applied to a compression-torsion composite loading test bench of a flexible drill rod in a bent state of the present invention, comprising the following steps:

[0104] Step 1: Place two flexible drill pipe short sections 6 in the holes of the support seat 13, connect the flexible drill pipe short section 6 and the transmission shaft 15 with a pressing clamp 7 at one end, and at the same time, press the clamp 7 to press the rotor 803 end face of the thrust bearing 8. Clamp the other end with a square rod clamp 601, and then fix the square rod clamp 601 in the groove of the corresponding end clamp (lower end clamp 4 and upper end clamp 5) by threaded connection, slide the lower end clamp 4 on the arc guide rail 2 to the required angle, and fix the end clamp with the guide rail clamp 3 by threaded connection.

[0105] Step 2: Start the torsion actuator 18 to apply a torsion load; start the compression actuator 11 to apply a compression load to achieve compression-torsion composite loading.

[0106] The present invention realizes the compression-torsion composite loading experiment of two flexible drill pipe short sections at a preset bending angle through precise mechanism design; by flexibly adjusting the position of the clamp on the arc guide rail and combining the dual loading of torsion and pressure, the present invention can accurately evaluate the performance of the flexible drill pipe short sections under different stress states, providing strong technical support for material strength analysis and optimization design.

[0107] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0108] It should be understood that the size of the serial numbers of each step in the content of the invention and the embodiments of the present invention does not absolutely mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A test bench for compression-torsion composite loading in a flexible drill pipe bending state, characterized in that: include: A base (1), a compression-twist composite device, a support seat (13), and an angle swing device arranged on the top of the base (1); The support seat (13) is arranged in the middle of the top of the base (1), and the support seat (13) is used to fix the middle part of the flexible drill pipe short section (6) to be tested; The compression-torsion composite device and the swing angle device are respectively arranged on both sides of the support seat (13) and are respectively connected to one end of the flexible drill rod short section (6); The compression-torsion composite device is used to provide a compression-torsion composite load for the flexible drill rod short section (6); and the swing angle device is used to swing the flexible drill rod short section (6) at a preset angle.

2. The compression-torsion composite loading test bench for the flexible drill rod in a bent state according to claim 1 is characterized in that: A through hole is provided in the middle of the top of the support seat (13), and the flexible drill rod short section (6) is slidably connected to the support seat (13) through the through hole.

3. The compression-torsion composite loading test bench in the bending state of the flexible drill rod according to claim 1 is characterized in that: The stand further comprises: a T-shaped guide rail (10) fixedly connected to the top of the base (1); The compression-twist composite device comprises: a compression support platform (12) fixedly connected to the base (1), a torsion housing (9) with a bottom slidably connected to the T-shaped guide rail (10), and a compression actuator (11); The torsion action housing (9) is provided with a torsion action housing side ear (14); one end of the pressing actuator (11) is connected to the pressing action support platform (12), and the other end is connected to the torsion action housing side ear (14); the force exerted by the pressing actuator (11) on the torsion action housing side ear (14) drives the torsion action housing (9) to slide along the T-shaped guide rail (10).

4. The compression-torsion composite loading test bench for the flexible drill rod in a bent state according to claim 3 is characterized in that: A torsion actuator (18) is fixed inside the torsion action housing (9); an extension shaft of the torsion actuator (18) is connected to a transmission shaft (15) via a torsion clamp (17); a thrust bearing (8) is installed on the transmission shaft (15); the thrust bearing (8) is connected to a pressure action clamp (7); and the pressure action clamp (7) is fixedly connected to the flexible drill pipe short section (6).

5. The compression-torsion composite loading test bench for the flexible drill rod in a bent state according to claim 4 is characterized in that: The thrust bearing (8) is connected to the pressing fixture (7) via a bearing seat (16); The thrust bearing (8) comprises a stator (801), a roller (802), and a rotor (803); the stator (801) is at least partially fixed in the torsion action housing (9); the stator (801) is connected to the rotor (803) via the roller (802); and the rotor (803) is in close contact with the action fixture (7).

6. The compression-torsion composite loading test bench in the bending state of the flexible drill rod according to claim 1 is characterized in that: The stand further comprises: an arc-shaped guide rail (2) fixedly connected to the top of the base (1); The swing angle device comprises: a lower end fixture (4) slidably connected to the arc-shaped guide rail (2), and guide rail fixtures (3) fixed to the top of the arc-shaped guide rail (2) and respectively located on both sides of the lower end fixture (4); An upper end clamp (5) is correspondingly arranged on the top of the lower end clamp (4), and after the lower end clamp (4) is connected to the upper end clamp (5), the end of the flexible drill rod short section (6) is fixed.

7. The compression-torsion composite loading test bench for the flexible drill rod in a bent state according to claim 6 is characterized in that: The angle swing device further comprises: a square rod clamp (601) for clamping the end of the flexible drill rod short section (6); Grooves are provided at corresponding positions on the upper part of the lower end clamp (4) and the lower part of the upper end clamp (5), and the square rod clamp (601) is installed in the cavity formed by merging the grooves of the lower end clamp (4) and the upper end clamp (5).

8. The compression-torsion composite loading test bench for the flexible drill rod in a bent state according to claim 6 is characterized in that: The position of the guide rail clamp (3) on the arc-shaped guide rail (2) is adjustable, and the lower end clamp (4) slides between the two guide rail clamps (3).

9. A method for testing a compression-torsion composite loading in a flexible drill pipe under a bent state, applied to a test bench for a compression-torsion composite loading in a flexible drill pipe under a bent state as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Placing the flexible drill rod short section (6) in the through hole of the support seat (13); The two ends of the flexible drill pipe short section (6) are respectively connected to the compression-torsion compound device and the swing angle device; The compression-torsion composite device applies a torsional load and a compressive load to the flexible drill rod short section (6) to achieve compression-torsion composite loading; and the swing angle device drives the flexible drill rod short section (6) to swing at a preset angle.

10. The compression-torsion composite loading test method of the flexible drill rod in a bent state according to claim 9, characterized in that: The stand comprises an arc-shaped guide rail (2) fixedly connected to the top of the base (1); the swing angle device comprises a guide rail clamp (3) and a lower end clamp (4); the lower end clamp (4) is slidably connected to the arc-shaped guide rail (2); the guide rail clamp (3) is arranged on both sides of the lower end clamp (4) and is located at the top of the arc-shaped guide rail (2); The preset angle is adjusted by adjusting the position of the guide rail clamp (3) on the arc-shaped guide rail (2).

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