Simulation test device and method for multifunctional offshore horizontal well drilling system

Abstract

The invention relates to a multifunctional offshore horizontal well drilling system simulation test device and method. The multifunctional offshore horizontal well drilling system simulation test device comprises a pool; a driving mechanism is arranged on the test bed; the driving mechanism is connected with the ocean platform model and can drive the ocean platform model to move; a marine riser water outlet is formed in the top of the marine riser model; a casing model; the drill string model is arranged in the marine riser model and the sleeve model in a penetrating manner; the top of the drilling column vertical section is connected with the bottom of the ocean platform model, and a drilling column water inlet is formed in the top of the drilling column vertical section; and the hydraulic system can be connected with the water inlet of the drill string and the water outlet of the marine riser through corresponding pipelines, and can adjust the pressure, flow and / or temperature of liquid in the drill string model. According to the invention, vibration response and friction response tests of an offshore horizontal well drilling system under various working conditions can be simulated more truly.

Description

Technical Field

[0001] The invention relates to the field of multifunctional offshore drilling system simulation, and in particular to a multifunctional offshore horizontal well drilling system simulation test device and method. Background Art

[0002] With the growing demand for oil and gas resources and the rapid development of drilling technology, the number and scale of offshore horizontal wells and extended reach wells are also increasing. Horizontal wells can more effectively extract oil and natural gas in geological reservoirs, and can improve productivity and extend the life of reserves. Horizontal wells are often used to collect thin oil and gas layers or fractured oil and gas reservoirs. Due to the characteristics of the horizontal section, horizontal wells can be used to penetrate oil layers with a long horizontal distance, increase the contact area between the well and the oil layer, improve oil recovery efficiency, and reduce production time.

[0003] Offshore oil drilling systems include components such as risers, drill strings, and casings that vibrate in response to the marine environment. Factors that cause vibration responses are: the effect of the movement of the offshore platform on the risers and drill strings; the external ocean currents causing vortex-induced vibrations in the risers; the force of the internal fluid on the drill string, risers, and casings; and the rotation of the rotary head causing vibrations in the drill string. These vibrations can cause fatigue failure of the drilling system. In addition, the above-mentioned situations often exist at the same time, posing a greater threat to the drilling system. Current offshore drilling test equipment is limited to test equipment for a single component, such as a drill string.

[0004] In addition, compared with traditional vertical wells, horizontal wells have special curved sections and horizontal sections. At large bending angles, due to the large rigidity of the drill string, the curved and horizontal sections of the drill string are generally attached to the casing wall, causing wear on the drill string and casing. In addition, since there are rock particles produced by drilling in the drilling fluid, these particles also wear the drill string and casing, causing huge losses to the oil field.

[0005] However, there is currently no test system to truly simulate the impact of different platform movement directions, speeds, and cycles on offshore drilling systems; the impact of different internal flow velocities, internal flow temperatures, and internal flow pressures on risers, drill strings, and casings; the impact of solid-liquid two-phase flow and different solid contents on risers, drill strings, and casings; and the wear mechanism of drill strings and casings caused by various factors. Summary of the invention

[0006] The purpose of the present invention is to provide a multifunctional offshore horizontal well drilling system simulation test device and method, which can more realistically simulate the vibration response and friction response test of the offshore horizontal well drilling system under various working conditions.

[0007] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] The present invention provides a multifunctional offshore horizontal well drilling system simulation test device, comprising:

[0009] A vertically arranged water pool has an intermediate plate at the bottom thereof, which divides the interior of the water pool into a water-containing chamber at the upper part and a hollow chamber at the lower part; a flow-making pump is arranged in the water-containing chamber;

[0010] A test bench is located on the top of the water tank and has a driving mechanism on the test bench;

[0011] The marine platform model, the driving mechanism is connected to the top of the marine platform model and can drive the marine platform model to move in a vertical direction and a first horizontal direction and a second horizontal direction perpendicular to each other;

[0012] The riser model has a top connected to the bottom of the offshore platform model, and a riser outlet is provided at the top of the riser model;

[0013] A casing model, comprising a casing vertical section, a casing curved section, a casing horizontal section and a casing end cover connected in sequence, wherein the top of the casing vertical section is detachably connected to the bottom of the watertight pipe model;

[0014] The drill string model is inserted into the riser model and the casing model; the drill string model includes a drill string vertical section, a drill string curved section and a drill string horizontal section connected in sequence, the top of the drill string vertical section is connected to the bottom of the offshore platform model, and a drill string water inlet is provided at the top of the drill string vertical section;

[0015] The hydraulic system can be connected to the water inlet of the drill string and the water outlet of the riser through corresponding pipelines, and can adjust the pressure, flow rate and / or temperature of the liquid in the drill string model.

[0016] In a preferred embodiment of the present invention, a drill string end cover is also connected to the end of the horizontal section of the drill string, a plurality of fluid holes are opened on the side wall of the drill string end cover, a transmission member is rotatably connected to the drill string end cover, and a driving member is also provided in the hollow cavity, the driving member can pass through the casing end cover and be connected to the transmission member to drive the transmission member to rotate.

[0017] In a preferred embodiment of the present invention, a mounting hole is provided on the casing end cover, the first end of the transmission member is connected to the drill string end cover through a bearing, and the second end of the transmission member is inserted into the mounting hole; a convex ring is convexly provided on the outer wall of the first end of the transmission member, and a push ring, a first ring body and a second ring body are sequentially sleeved on the outside of the transmission member from the first end to the second end; an annular first flange is convexly provided on the outer wall of the end portion of the second ring body close to the first ring body, the first flange can be enclosed with the bottom inner wall of the vertical section of the casing and the inner wall of the casing end cover to form a first sealing ring groove, and a first sealing ring is embedded in the first sealing ring groove; an annular second flange is convexly provided on the inner wall of the end portion of the first ring body close to the second ring body, one end of the push ring can be movably inserted into the first ring body and can be enclosed with the second flange to form a second sealing ring groove, and a second sealing ring is embedded in the second sealing ring groove; a plurality of push rods are axially spaced at the other end of the push ring, the plurality of push rods can be movably inserted into a plurality of through holes on the convex ring, a spring is sleeved on each push rod, and the two ends of the spring can respectively abut between the convex ring and the push ring.

[0018] In a preferred embodiment of the present invention, a rock particle inlet is provided on the bottom side wall of the horizontal section of the casing, and the hydraulic system is also connected to the rock particle inlet through a corresponding pipeline to inject fluid containing rock particles into the annulus between the casing model and the drill string model.

[0019] In a preferred embodiment of the present invention, there are two flow-generating pumps, and the flow-generating ports of the two flow-generating pumps are arranged back to back.

[0020] In a preferred embodiment of the present invention, a camera is also provided outside the water pool for taking pictures of the riser model and the drill string model to record the displacement of the riser model and the drill string model.

[0021] In a preferred embodiment of the present invention, the water pool is a transparent structure, the riser model is a transparent tube, and an identification piece is provided on the outer wall of the riser model, and the drill string model is a color tube, and the color of the identification piece and the color tube are different.

[0022] In a preferred embodiment of the present invention, the driving mechanism includes a transverse hydraulic cylinder, a longitudinal hydraulic cylinder and a vertical hydraulic cylinder, one end of the transverse hydraulic cylinder is connected to the vertical hydraulic cylinder, and can drive the vertical hydraulic cylinder to move horizontally along a first horizontal direction, and the first horizontal direction is parallel to the axial direction of the horizontal section of the drill string; one end of the longitudinal hydraulic cylinder is connected to the vertical hydraulic cylinder, and can drive the vertical hydraulic cylinder to move horizontally along a second horizontal direction; the vertical hydraulic cylinder is connected to the top of the marine platform model, and can drive the marine platform model to move up and down in the vertical direction.

[0023] In a preferred embodiment of the present invention, a sleeve is provided at the joint position between the bottom of the watertight pipe model and the top of the vertical section of the casing, the sleeve is connected to the watertight pipe model and the vertical section of the casing by corresponding fasteners, a sealing ring is installed between the sleeve and the mounting hole provided on the middle plate, and a waterproof sealant is provided at the connection between the sleeve and the middle plate.

[0024] In a preferred embodiment of the present invention, a bending preventer is further provided on the outside of the watertight pipe, and the bending preventer includes a mounting ring and a plurality of spiral rings, the mounting ring is connected to the bottom of the offshore platform model, and the top of each spiral ring is connected to the bottom of the mounting ring; the plurality of spiral rings are arranged side by side along a busbar and are spirally wound around the vertical axis of the mounting ring, and adjacent spiral rings are arranged closely, and the bottom ends of the spiral rings are connected to adjacent spiral rings through clamps.

[0025] In a preferred embodiment of the present invention, the spiral radius and the number of turns of each point on the spiral center line corresponding to each spiral ring satisfy the following formula:

[0026]

[0027] Among them, y represents the spiral radius of each point on the spiral center line corresponding to the spiral ring, x represents the number of circles corresponding to each point on the spiral center line corresponding to the spiral ring, and a, b, c and d are all coefficients.

[0028] In a preferred embodiment of the present invention, a plurality of anti-friction structures are axially spaced outside the horizontal section of the drill string, the anti-friction structures include two fixed rings sleeved on the horizontal section of the drill string and arranged at intervals, and a spiral rib spirally wound around the axis of the horizontal section of the drill string, both ends of the spiral rib are respectively connected to the two fixed rings, and a plurality of rolling balls are sleeved on the spiral rib, and at least some of the balls can roll in contact with the inner wall of the horizontal section of the casing.

[0029] In a preferred embodiment of the present invention, the hydraulic system includes a water injection hydraulic source, a pressurized hydraulic source, a first control valve, a second control valve and a third control valve. The water injection hydraulic source is connected to the drill string water inlet through a first pipeline in an on-off manner, the pressurized hydraulic source is connected to the first control valve in an on-off manner through a second pipeline, the first control valve is connected to the drill string water inlet and the second control valve through a third pipeline and a fourth pipeline, respectively, the second control valve is connected to the drill string water inlet through a fifth pipeline and a sixth pipeline, respectively, and a pressure gauge is provided on the third pipeline, and a first adjustable flow valve and a first adjustable flow valve are provided on the fourth pipeline. A flow meter is provided, and a heater and a thermometer are arranged on the sixth pipeline; the first control valve can control the second pipeline to be connected with the third pipeline or the fourth pipeline, and the second control valve can control the fourth pipeline to be connected with the fifth pipeline or the sixth pipeline; the third control valve is connected to the water outlet of the watertight pipe through the seventh pipeline, and the third control valve can also be connected to the eighth pipeline and the ninth pipeline in an on-off manner. A filter and a cooler are arranged in sequence along the fluid flow direction on the seventh pipeline, and a second adjustable flow valve is arranged on the ninth pipeline. The third control valve can control the seventh pipeline to be connected with the eighth pipeline or the ninth pipeline.

[0030] In a preferred embodiment of the present invention, a rock particle inlet is provided on the bottom side wall of the horizontal section of the casing, and the hydraulic system also includes a rock particle hydraulic source, which is connected to the rock particle inlet in an on-off manner through a tenth pipeline, and a second flow meter and a third adjustable flow valve are provided on the tenth pipeline.

[0031] In a preferred embodiment of the present invention, a first one-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a fifth one-way valve, a sixth one-way valve and a seventh one-way valve are respectively provided in the first pipeline, the third pipeline, the fourth pipeline, the sixth pipeline, the eighth pipeline, the ninth pipeline and the tenth pipeline.

[0032] In a preferred embodiment of the present invention, the first control valve, the second control valve and the third control valve are all three-position four-way valves, and the first switch valve, the second switch valve, the third switch valve, the fourth switch valve and the fifth switch valve are respectively provided in the first pipeline, the second pipeline, the eighth pipeline, the ninth pipeline and the tenth pipeline, and the first switch valve, the second switch valve, the third switch valve, the fourth switch valve and the fifth switch valve are all two-position two-way valves.

[0033] In a preferred embodiment of the present invention, a first pilot-type relief valve is also connected to the second pipeline near the water injection hydraulic source, and a second pilot-type relief valve is also connected to the tenth pipeline near the rock particle hydraulic source.

[0034] In a preferred embodiment of the present invention, the multifunctional offshore horizontal well drilling system simulation test device also includes a control device, and the flow pump, the driving mechanism and the hydraulic system of the control device are all electrically connected.

[0035] The present invention also provides a multifunctional offshore horizontal well drilling system simulation test method, which uses the above-mentioned multifunctional offshore horizontal well drilling system simulation test device to conduct a test. The multifunctional offshore horizontal well drilling system simulation test method includes:

[0036] S1. Assemble a multifunctional offshore horizontal well drilling system simulation test device;

[0037] S2, injecting fluid into the water inlet of the drill string, starting the test, adjusting the test influencing factors, and recording the vibration displacement of the riser model and the drill string model during the test;

[0038] The adjustment test influencing factors include: using a driving mechanism to adjust the amplitude and period of the movement of the offshore platform model in the vertical direction, the first horizontal direction and / or the second horizontal direction, and using a hydraulic system to adjust the pressure, flow rate and / or temperature of the liquid in the drill string model;

[0039] S3. After the test, take out the drill string model after the test, and compare the drill string model after the test with the drill string model before the test to obtain the wear amount and wear position of the drill string model after the test;

[0040] S4. Repeat steps S1-S3 and use different experimental influencing factors to conduct multiple groups of experiments.

[0041] In a preferred embodiment of the present invention, in step S2, adjusting the test influencing factors also includes using a hydraulic system to inject a fluid containing rock particles into a rock particle inlet on the horizontal section of the casing and adjusting the rock particle content, flow rate, temperature and / or pressure of the fluid containing rock particles, and using a driving member to drive a transmission member rotatably connected to a drill string end cover at the end of the horizontal section of the drill string and adjusting the rotation speed of the driving member.

[0042] In a preferred embodiment of the present invention, in step S1, during the process of assembling the multifunctional offshore horizontal well drilling system simulation test device, a plurality of anti-friction structures are also set between the drill string model and the casing model, and the anti-friction structures include a plurality of balls and can be in rolling contact with the casing model.

[0043] In a preferred embodiment of the present invention, the multifunctional offshore horizontal well drilling system simulation test method further comprises:

[0044] S5. Determine the factors affecting drill string wear based on multiple groups of tests;

[0045] S6. Fit the factors affecting drill string wear and the wear amount of the drill string model to obtain a prediction model between the maximum wear depth of the drill string and the factors affecting drill string wear.

[0046] In a preferred embodiment of the present invention, the prediction model is: h = Ap +A v +A d +A c +A t ;

[0047] Among them, A p =a1p 3 +b1p 2 +c1p+d1,A v =a2v 3 +b2v 2 +c2v+d2,A d =a3d 3 +b3d 2 +c3d+d3,A c =a4C 3 +b4C 2 +c4C+d4,A t =a5t 3 +b5t 2 +c5t+d5;

[0048] h represents the maximum wear depth of the worn drill string under the action of various factors, p represents the internal fluid pressure of the worn drill string, v represents the fluid flow rate in the worn drill string, d represents the diameter of the rock particles in the worn drill string, C represents the content of rock particles in the fluid in the worn drill string, A represents the diameter of the rock particles in the worn drill string, p A represents the maximum wear of the drill string under the action of internal fluid pressure. v A represents the maximum wear of the drill string under the action of fluid flow rate. d A represents the maximum wear of the drill string under the effect of rock particle diameter. c A represents the maximum wear of the drill string under the influence of the rock particle content in the fluid. t It represents the maximum wear amount of the worn drill string under the action of fluid impact time. a1, b1, c1, d1, a2, b2, c2, d2, a3, b3, c3, d3, a4, b4, c4 and d4 are all coefficients.

[0049] As described above, the simulation test device and method of the present invention can drive the marine platform model to move horizontally, longitudinally and vertically in the first horizontal direction, the second horizontal direction and the vertical direction respectively by using the driving mechanism on the test bench, and can adjust the amplitude and period of the horizontal movement, longitudinal movement and vertical swing of the marine platform model, so as to simulate the vibration response of the offshore drilling system under the movement of the marine platform. The flow pump arranged in the water-containing cavity can simulate the sea current and the oscillating flow, which is conducive to simulating the behavior of the external sea current in the marine environment causing vortex-induced vibration of the watertight pipe. The hydraulic system can be used to inject fluid into the drill string model, and the pressure, flow rate and / or temperature of the injected fluid can also be adjusted, thereby more realistically simulating the impact of different marine platform movement directions, movement speeds, and movement cycles on the offshore drilling system, the impact of different external ocean currents on the vortex-induced vibration of the riser, and the impact of different internal flow velocities, internal flow temperatures, and internal flow pressures on the riser, drill string, and casing; using the design of this device to inject fluid into the drill string model, the friction test of wear on the drill string and casing can also be studied, thereby facilitating the simulation of vibration response and friction response tests of offshore horizontal well drilling systems under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0051] in:

[0052] Figure 1 A stereoscopic diagram of the multifunctional offshore horizontal well drilling system simulation test device provided by the present invention.

[0053] Figure 2 A front view of the multifunctional offshore horizontal well drilling system simulation test device provided by the present invention.

[0054] Figure 3 for Figure 2 Section view along AA direction.

[0055] Figure 4 for Figure 2 Top view of the .

[0056] Figure 5 for Figure 4 Section view along BB direction.

[0057] Figure 6 for Figure 5 A partial enlarged view of the test bench.

[0058] Figure 7 for Figure 5 A partial enlarged view of the shaft sleeve.

[0059] Figure 8 for Figure 5A partial enlarged view of the drive member.

[0060] Fig. 9 A three-dimensional diagram of the multifunctional offshore horizontal well drilling system simulation test device provided by the present invention with the water pool removed.

[0061] Fig.10 A three-dimensional diagram of the test bench provided by the present invention.

[0062] Fig.11 A three-dimensional diagram of the anti-bending device provided by the present invention.

[0063] Fig.12 A three-dimensional diagram of the anti-friction structure provided by the present invention.

[0064] Fig.13 A working principle diagram of the hydraulic control provided by the present invention.

[0065] Description of Figure Numbers:

[0066] 1. Water tank; 10. Middle plate; 11. Test bench; 111. Longitudinal hydraulic cylinder fixing plate; 1111. Longitudinal hydraulic cylinder fixing groove; 112. Transverse hydraulic cylinder fixing plate; 1121. Transverse hydraulic cylinder fixing groove;

[0067] 2. Driving mechanism; 21. Horizontal hydraulic cylinder; 22. Longitudinal hydraulic cylinder; 23. Vertical hydraulic cylinder; 231. Vertical hydraulic cylinder fixing piece; 24. Roller; 25. Connecting chuck; 251. Bolt;

[0068] 3. Offshore platform model; 31. Upper platform; 32. Lower platform; 33. Connecting column;

[0069] 4. Riser model; 41. Riser outlet; 42. Bushing; 421. Bolt; 422. Sealing ring; 423. Waterproof sealant;

[0070] 5. Casing model; 51. Casing vertical section; 52. Casing bending section; 53. Casing horizontal section; 531. Rock particle inlet; 54. Casing end cap; 541. Screw; 55. Casing fixing seat;

[0071] 6. Drill string model; 61. Drill string vertical section; 611. Drill string water inlet; 62. Drill string bending section; 63. Drill string horizontal section; 64. Drill string end cover; 641. Liquid hole; 642. Screw; 65. Transmission member; 651. Convex ring; 652. Push ring; 6521. Push rod; 653. First ring body; 654. Second ring body; 655. First sealing ring; 656. Second sealing ring; 657. Spring; 66. Bearing; 67. Driving member; 671. Support frame; 672. Bolt;

[0072] 7. anti-bending device; 71. mounting ring; 72. spiral ring; 721. first spiral ring; 722. second spiral ring; 723. third spiral ring; 73. clamp;

[0073] 8. Anti-friction structure; 81. Fixed ring; 82. Spiral ribs; 83. Balls;

[0074] 9. Hydraulic system;

[0075] 91, water injection hydraulic source; 911, first pipeline; 9111, first switch valve; 9112, first check valve;

[0076] 92, pressurized hydraulic source; 921, second pipeline; 9211, second switch valve; 9212, first pilot relief valve;

[0077] 93, first control valve; 931, third pipeline; 9311, second check valve; 9312, pressure gauge; 932, fourth pipeline; 9321, third check valve; 9322, first adjustable flow valve; 9323, first flow meter;

[0078] 94, second control valve; 941, fifth pipeline; 942, sixth pipeline; 9421, fourth check valve; 9422, heater; 9423, thermometer;

[0079] 95, third control valve; 951, seventh pipeline; 9511, filter; 9512, cooler; 952, eighth pipeline; 9521, fifth check valve; 9522, third switch valve; 953, ninth pipeline; 9531, sixth check valve; 9532, second adjustable throttle valve; 9533, fourth switch valve;

[0080] 96, rock particle hydraulic source; 961, tenth pipeline; 9611, fifth switch valve; 9612, seventh one-way valve; 9613, third adjustable flow valve; 9614, second flow meter; 9615, second pilot relief valve. DETAILED DESCRIPTION

[0081] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0082] like Figures 1 to 13 As shown, the present application provides a multifunctional offshore horizontal well drilling system simulation test device, comprising:

[0083] A vertically arranged water pool 1 has an intermediate plate 10 at the bottom thereof, which divides the interior of the water pool 1 into a water-containing chamber at the upper part and a hollow chamber at the lower part; a flow-generating pump is arranged in the water-containing chamber;

[0084] A test bench 11 is arranged on the top of the water pool 1, and a driving mechanism 2 is arranged on the test bench 11;

[0085] The marine platform model 3, the driving mechanism 2 is connected to the top of the marine platform model 3 and can drive the marine platform model 3 to move in a vertical direction and a first horizontal direction and a second horizontal direction perpendicular to each other;

[0086] The riser model 4 has a top connected to the bottom of the offshore platform model 3, and a riser outlet 41 is provided at the top of the riser model 4;

[0087] The casing model 5 comprises a casing vertical section 51, a casing curved section 52, a casing horizontal section 53 and a casing end cover 54 which are connected in sequence, and the top of the casing vertical section 51 is detachably connected to the bottom of the watertight pipe model 4;

[0088] The drill string model 6 is inserted into the watertight pipe model 4 and the casing model 5; the drill string model 6 includes a drill string vertical section 61, a drill string curved section 62 and a drill string horizontal section 63 connected in sequence, the top of the drill string vertical section 61 is connected to the bottom of the offshore platform model 3, and a drill string water inlet 611 is provided at the top of the drill string vertical section 61;

[0089] The hydraulic system 9 can be connected to the drill string water inlet 611 and the riser water outlet 41 through corresponding pipelines, and can adjust the pressure, flow and / or temperature of the liquid in the drill string model 6.

[0090] Therefore, the simulation test device in the present application can drive the marine platform model 3 to move horizontally, longitudinally and vertically in the first horizontal direction, the second horizontal direction and the vertical direction respectively by using the driving mechanism 2 on the test bench 11, and can adjust the amplitude and period of the horizontal movement, longitudinal movement and vertical swing of the marine platform model 3, so as to simulate the vibration response of the offshore drilling system under the movement of the marine platform. The flow pump arranged in the water-containing cavity can simulate the sea current and the oscillating flow, which is conducive to simulating the behavior of the external sea current in the marine environment causing vortex-induced vibration of the watertight pipe. The hydraulic system 9 can be used to inject fluid into the drill string model 6, and the pressure, flow rate and / or temperature of the injected fluid can be adjusted, thereby more realistically simulating the impact of different marine platform movement directions, movement speeds, and movement cycles on the offshore drilling system, the impact of different external ocean currents on the vortex-induced vibration of the riser, and the impact of different internal flow velocities, internal flow temperatures, and internal flow pressures on the riser, drill string, and casing; using the design of this device, after injecting fluid into the drill string model 6, the friction test of wear on the drill string and casing can be studied, thereby facilitating the simulation of the vibration response and friction response tests of the offshore horizontal well drilling system under various working conditions.

[0091] In a specific implementation, since the rotation of the drill bit will cause the vibration of the drill string during the actual drilling process, the device of the present application is also provided with a device for simulating the vibration of the drill string caused by the rotation of the drill bit. Figure 8 A drill string end cover 64 is also connected to the end of the drill string horizontal section 63. A plurality of fluid holes 641 are provided on the side wall of the drill string end cover 64. A transmission member 65 is rotatably connected to the drill string end cover 64. A driving member 67 is also provided in the hollow cavity. The driving member 67 can pass through the casing end cover 54 and be connected to the transmission member 65 to drive the transmission member 65 to rotate.

[0092] The casing end cover 54 can be connected to the end of the casing horizontal section 53 by means of screws 541. A gap is left between the end of the drill string horizontal section 63 and the casing end cover 54. The drill string end cover 64 can be connected to the end of the drill string horizontal section 63 (i.e., the end away from the drill string curved section 62) by means of screws 642. The drill string end cover 64 can adopt a cylindrical structure with an open first end and a closed second end. A convex ring 651 is convexly provided on the outer wall of the first end of the drill string end cover 64. The convex ring 651 is connected to the end of the drill string horizontal section 63 by means of screws 642. A plurality of liquid holes 641 are provided on the side wall of the drill string end cover 64. Water in the drill string model 6 enters the annulus between the casing model 5 and the drill string model 6 through these small holes.

[0093] A mounting hole is provided on the casing end cap 54, and the first end of the transmission member 65 is connected to the drill string end cap 64 through a bearing 66, and the second end of the transmission member 65 is inserted into the mounting hole and can rotate relative to the mounting hole. The driving member 67 can be, for example, a motor, and the housing of the motor is fixed to the bottom plate of the pool 1 through a support frame 671 and a bolt 672, and the output shaft of the motor is fixedly connected to the second end of the transmission member 65. By adjusting the speed of the motor, the vibration effect of drill bits with different speeds on the drill string model 6 can be simulated.

[0094] In order to ensure the sealing performance, a convex ring 651 is convexly provided on the outer wall of the first end of the transmission member 65, and a push ring 652, a first ring body 653 and a second ring body 654 are sequentially sleeved on the transmission member 65 from the first end to the second end; a first annular flange is convexly provided on the outer wall of the end of the second ring body 654 close to the first ring body 653, and the first flange can be enclosed with the bottom inner wall of the sleeve vertical section 51 and the inner wall of the sleeve end cover 54 to form a first sealing ring groove, and a first sealing ring 655 is embedded in the first sealing ring groove; a convex ring 652 is convexly provided on the inner wall of the end of the first ring body 653 close to the second ring body 654 An annular second flange, one end of the push ring 652 can be movably inserted in the first ring body 653 and can be enclosed with the second flange to form a second sealing ring groove, and a second sealing ring 656 is embedded in the second sealing ring groove; a plurality of push rods 6521 are axially spaced at the other end of the push ring 652, and the plurality of push rods 6521 can be movably inserted in a plurality of through holes on the convex ring 651, and a spring 657 is sleeved on each push rod 6521, and the two ends of the spring 657 can respectively press between the convex ring 651 and the push ring 652, and the second ring body 654 can press against the inner wall of the sleeve end cover 54.

[0095] During the test, when the water pressure in the annulus increases, the push ring 652 will Figure 8 The transmission member 65 is moved rightward from the position shown in the figure and squeezes the second sealing ring 656, so that the sealing effect is better. The transmission member 65 is a cylindrical structure with an open first end and a closed second end. The output shaft of the motor passes through the through hole on the second end surface of the transmission member 65 and is fixed to the transmission member 65. A partition plate is also provided in the transmission member 65 so that the end of the motor is located in the closed cavity surrounded by the partition plate and the second end of the transmission member 65. The first ring body 653 and the second ring body 654 are provided to respectively install two sealing rings, which can ensure that the sealing rings are pressed more tightly and have a good sealing effect.

[0096] Further preferably, a rock particle inlet 531 is provided on the bottom side wall of the horizontal section of the casing 53, and the hydraulic system 9 is also connected to the rock particle inlet 531 through a corresponding pipeline to inject fluid containing rock particles into the annulus between the casing model 5 and the drill string model 6, so as to simulate the influence of the rock particles generated by drilling in the actual drilling fluid on the drill string and casing.

[0097] The number of the above-mentioned flow pumps is preferably two, and the flow ports of the two flow pumps are arranged back to back to form a bidirectional flow pump. When the water containing cavity of the pool 1 is filled with water, it can simulate bidirectional ocean currents and oscillating currents.

[0098] Furthermore, a camera is provided outside the water pool 1 for taking pictures of the riser model 4 and the drill string model 6 to record the displacement of the riser model 4 and the drill string model 6 .

[0099] In order to facilitate photographing and recording, the water pool 1 is a transparent structure, the watertight pipe model 4 is a transparent tube, and an identification piece is provided on the outer wall of the watertight pipe model 4. The drill string model 6 is a color tube, and the color of the identification piece and the color tube are different.

[0100] The camera preferably uses a high-speed camera, and the specific number depends on the needs. The above-mentioned water pool 1 is a pool structure with an open top formed by a bottom plate and a side plate. The water pool 1 can be made of a transparent acrylic plate. The above-mentioned identification parts can be made of colored dot pieces. For example, the water riser model 4 can be made of a transparent rubber tube, and black dots are attached to the outer wall of the water riser model 4 as identification parts to facilitate the high-definition camera to capture the position of the water riser model 4. The drill string model 6 is made of a colored hollow rubber tube, and the color is more conducive to the high-definition camera to capture the displacement of the drill string model 6.

[0101] Furthermore, in order to facilitate the driving mechanism 2 to drive the marine platform model 3 to move in various directions, the driving mechanism 2 includes a transverse hydraulic cylinder 21, a longitudinal hydraulic cylinder 22 and a vertical hydraulic cylinder 23. One end of the transverse hydraulic cylinder 21 is connected to the vertical hydraulic cylinder 23, and can drive the vertical hydraulic cylinder 23 to move horizontally along a first horizontal direction, and the first horizontal direction is parallel to the axial direction of the horizontal section 63 of the drill string; one end of the longitudinal hydraulic cylinder 22 is connected to the vertical hydraulic cylinder 23, and can drive the vertical hydraulic cylinder 23 to move horizontally along a second horizontal direction; the vertical hydraulic cylinder 23 is connected to the top of the marine platform model 3, and can drive the marine platform model 3 to move up and down in the vertical direction.

[0102] The above-mentioned test bench 11 can adopt a frame structure and be clamped on the top of the pool 1. The test bench 11 is provided with a longitudinal hydraulic cylinder fixing plate 111 and a transverse hydraulic cylinder fixing plate 112. The longitudinal hydraulic cylinder fixing plate 111 is provided with a longitudinal hydraulic cylinder fixing groove 1111. The length direction of the longitudinal hydraulic cylinder fixing groove 1111 extends along the first horizontal direction. The other end of the longitudinal hydraulic cylinder 22 can be slidably inserted into the longitudinal hydraulic cylinder fixing groove 1111, so that when the transverse hydraulic cylinder 21 drives the vertical hydraulic cylinder 23 to move along the first horizontal direction, the longitudinal hydraulic cylinder 22 can also move synchronously together. The transverse hydraulic cylinder fixing plate 112 is provided with a transverse hydraulic cylinder fixing groove 1121. The length direction of the transverse hydraulic cylinder fixing groove 1121 extends along the second horizontal direction. The other end of the transverse hydraulic cylinder 21 can be slidably inserted into the transverse hydraulic cylinder fixing groove 1121, so that when the longitudinal hydraulic cylinder 22 drives the vertical hydraulic cylinder 23 to move along the second direction, the transverse hydraulic cylinder 21 can also move synchronously together.

[0103] Furthermore, rollers 24 are installed at the other end of the longitudinal hydraulic cylinder 22 and the other end of the transverse hydraulic cylinder 21. The rollers 24 can be slidably inserted into the transverse hydraulic cylinder fixing groove 1121 and the longitudinal hydraulic cylinder fixing groove 1111 to reduce friction during sliding.

[0104] For ease of installation, the other end of the longitudinal hydraulic cylinder 22 and the other end of the transverse hydraulic cylinder 21 are connected to the connecting chuck 25 through fasteners (such as bolts 251), and the roller 24 can be rotatably mounted on the mounting shaft on the connecting chuck 25. A vertical hydraulic cylinder fixing part 231 is fixedly mounted outside the housing of the vertical hydraulic cylinder 23. One end of the longitudinal hydraulic cylinder 22 and one end of the transverse hydraulic cylinder 21 can be connected to the vertical hydraulic cylinder fixing part 231 through fasteners (such as bolts). The vertical hydraulic cylinder fixing part 231 mainly plays the role of connecting and supporting the vertical hydraulic cylinder 23. The end of the telescopic rod of the vertical hydraulic cylinder 23 is connected to the top of the marine platform model 3 through fasteners (such as bolts). The bottom of the marine platform model 3 is connected to the top of the watertight pipe model 4 and the top of the drill string model 6 through fasteners (such as bolts).

[0105] Offshore platform model 3 can be, for example, Figure 6 The structure shown includes an upper platform 31 and a lower platform 32 spaced apart from each other, and a connecting column 33 connected between the upper platform 31 and the lower platform 32. The top of the drill string model 6 and the top of the watertight pipe model 4 can be designed as a closed end or an open end and closed by the lower platform 32 as needed. For example, in this embodiment, the top of the drill string model 6 is a closed end and passes through the lower platform 32 and is located in the interval between the upper platform 31 and the lower platform 32. The drill string water inlet 611 is provided on the top closed end of the drill string model 6 to facilitate the connection of corresponding pipelines; the top of the watertight pipe model 4 is an open end and is closed by the lower platform 32. The watertight pipe outlet 41 passes through the lower platform 32 from the top of the watertight pipe model 4 and is located in the interval between the upper platform 31 and the lower platform 32 to facilitate the connection of corresponding pipelines.

[0106] Furthermore, a sleeve 42 is provided at the joint position between the bottom of the watertight pipe model 4 and the top of the vertical section 51 of the casing, and the sleeve 42 is connected to the watertight pipe model 4 and the vertical section 51 of the casing through corresponding fasteners. A sealing ring 422 is installed between the sleeve 42 and the mounting hole opened on the middle plate 10, and a waterproof sealant 423 is provided at the connection between the sleeve 42 and the middle plate 10.

[0107] Reference Figure 7 , the shaft sleeve 42 is covered at the connection between the watertight pipe model 4 and the casing model 5, and is connected to the watertight pipe model 4 and the casing model 5 by bolts 421. The function of the shaft sleeve 42 is to connect the watertight pipe model 4 and the casing model 5. The water pool 1 is an upper and lower double-layer structure separated by the middle plate 10. The upper layer of the water pool 1 is filled with water, and the lower layer of the water pool 1 is a hollow layer. The shaft sleeve 42 passes through the middle plate 10 of the water pool 1. The sealing method between the shaft sleeve 42 and the middle plate 10 is a sealing ring 422, and a waterproof sealant 423 is applied to the connection between the shaft sleeve 42 and the middle plate 10 to ensure the sealing effect here.

[0108] The sleeve model 5 is preferably a transparent structure. During production, sleeve models 5 of various specifications can be produced. The inner wall roughness of each sleeve model 5 is different. By replacing sleeve models 5 of different roughness, more experimental studies can be performed. The sleeve model 5 can be made of a transparent acrylic tube, for example. During production, multiple acrylic tubes are produced, and the roughness of the inner wall of each acrylic tube is different.

[0109] In order to facilitate the support and fixation of the sleeve model 5, a plurality of sleeve fixing seats 55 are axially spaced apart on the sleeve model 5, and the sleeve fixing seats 55 are connected to the bottom plate of the pool 1 through fasteners (such as bolts).

[0110] Further preferably, refer to Figure 6 and Fig.11 An anti-bending device 7 is also provided outside the watertight pipe. The anti-bending device 7 includes a mounting ring 71 and a plurality of spiral rings 72. The mounting ring 71 is connected to the bottom of the offshore platform model 3. The top of each spiral ring 72 is connected to the bottom of the mounting ring 71. The plurality of spiral rings 72 are arranged side by side along a busbar and are spirally wound around the vertical axis of the mounting ring 71. Adjacent spiral rings 72 are arranged closely, and the bottom ends of the spiral rings 72 are connected to adjacent spiral rings 72 through clamps 73.

[0111] The setting of the anti-bending device 7 can effectively prevent the riser model 4 from being bent too much. The spiral radius and the number of turns of each point on the spiral center line corresponding to each spiral ring 72 satisfy a nonlinear relationship, specifically satisfying the following formula:

[0112]

[0113] Among them, y represents the spiral radius of each point on the spiral center line corresponding to the spiral ring 72, x represents the number of circles corresponding to each point on the spiral center line corresponding to the spiral ring 72, and a, b, c and d are all coefficients.

[0114] 0≤x≤X, x can be a decimal, X represents the total number of rotations from the top to the bottom of the spiral ring 72 (the top and bottom of the spiral ring 72 are the starting point and the end point of the spiral centerline), and y is the spiral radius of the corresponding point on the spiral centerline corresponding to the spiral ring 72 at the xth turn. a, b, c, d∈(0.001 0.04), these four coefficients can be set within the range of 0.001-0.04 as needed. By adjusting the coefficients a, b, c, d, the shape of the spiral ring 72 with any curvature can be obtained.

[0115] The bottom of the offshore platform model 3 can be connected to the mounting ring 71 by fasteners (such as bolts). The diameters of the spiral rings 72 are the same, and the adjacent spiral rings 72 are arranged closely. The gap between two adjacent spiral rings 72 is small, and the interval between two adjacent circles in the same spiral ring 72 along the busbar direction is close to the diameter of n-1 spiral rings 72, where n is the total number of spiral rings 72. The above busbar is preferably an arc, and the diameter of the entire anti-bending device 7 gradually increases from top to bottom, and the anti-bending effect is better; the number of spiral rings 72 is also determined according to needs,

[0116] For example, in this embodiment, the number of spiral rings 72 is three, which are respectively recorded as a first spiral ring 721, a second spiral ring 722 and a third spiral ring 723. Fig.11 As shown, the tops of the three spiral rings 72 are welded to the bottom surface of the mounting ring 71, the tops of the three spiral rings 72 are distributed at 120 degrees, and three clamps 73 are respectively provided at the bottoms of the three spiral rings 72 to respectively fix the three spiral rings 72. For the first spiral ring 721, the interval L between two adjacent turns of the first spiral ring 721 along the generatrix direction is close to the diameter of the two spiral rings 72.

[0117] Furthermore, since friction easily occurs between the drill string model 6 and the casing model 5, the friction increases the resistance of the drill string during the drilling process. Therefore, the device of the present application is provided with an anti-friction structure 8. Specifically, refer to Figure 5 and Fig.12 A plurality of anti-friction structures 8 are sleeved axially and spaced apart outside the horizontal section 63 of the drill string. The anti-friction structure 8 includes two fixed rings 81 sleeved on the horizontal section 63 of the drill string and arranged at intervals, and a spiral rib 82 spirally wound around the axis of the horizontal section 63 of the drill string. Both ends of the spiral rib 82 are respectively connected to the two fixed rings 81. A plurality of rolling balls 83 are sleeved on the spiral rib 82, and at least some of the balls 83 can roll in contact with the inner wall of the horizontal section 53 of the casing.

[0118] The anti-friction structure 8 is connected to the drill string through two fixing rings 81, and a spiral rib 82 is connected between the two fixing rings 81. The entire spiral rib 82 can be Fig.12 The structure shown in the figure is a structure with a diameter gradually decreasing from the middle to the two ends and a small size at both ends and a large size in the middle. The spiral rib 82 is strung with steel balls, and the steel balls can roll on the spiral rib 82. By using the method of sleeve steel balls and filling the spiral rib 82 with balls 83 (that is, two adjacent balls 83 are arranged closely together with a small gap), the sliding friction between the drill string model 6 and the casing model 5 can be converted into rolling friction, thereby reducing the resistance of drilling. In addition, due to the reduction of friction, the risk of wear of the drill string and the casing is also reduced.

[0119] During the test, it can be divided into two major groups of tests. In one group of tests, the anti-friction structure 8 is not installed to study the friction mechanism, that is, to study the wear of the drill string when there is friction between the drill string and the casing; in the other group of tests, the anti-friction structure 8 is installed to study the anti-friction mechanism, that is, to study the wear of the drill string when the anti-friction structure 8 can reduce the friction between the drill string and the casing.

[0120] In an optional embodiment, the hydraulic system 9 includes a hydraulic source, which is connected to the drill string water inlet 611 through an inlet pipeline, and is provided with a pressure gauge 9312, a first adjustable flow valve 9322, a flow meter, a heater 9422 and a thermometer 9423 on the inlet pipeline. The water outlet 41 of the watertight pipe is connected to an outlet pipeline, and is provided with a filter 9511, a cooler 9512 and a second adjustable flow valve 9532 on the outlet pipeline. When injecting fluid into the drill string model 6, the fluid pressure can be controlled according to the data detected by the pressure gauge 9312. The flow rate of the fluid injected into the drill pipe model can be conveniently adjusted by the first adjustable flow valve 9322, the flow meter and the second adjustable flow valve 9532. The temperature of the injected fluid can be adjusted by the heater 9422 and the thermometer 9423.

[0121] In another preferred embodiment, referring to Fig.13 The hydraulic system 9 includes a water injection hydraulic source 91, a pressurized hydraulic source 92, a first control valve 93, a second control valve 94 and a third control valve 95. The water injection hydraulic source 91 is connected to the drill string water inlet 611 through a first pipeline 911, and the pressurized hydraulic source 92 is connected to the first control valve 93 through a second pipeline 921. The first control valve 93 is also connected to the drill string water inlet 611 and the second control valve 94 through a third pipeline 931 and a fourth pipeline 932, respectively. The second control valve 94 is also connected to the drill string water inlet 611 and the second control valve 94 through a fifth pipeline 941 and a sixth pipeline 942. The pipelines 942 are respectively connected to the drill string water inlet 611, and a pressure gauge 9312 is provided on the third pipeline 931, a first adjustable flow valve 9322 and a first flow meter 9323 are provided on the fourth pipeline 932, and a heater 9422 and a thermometer 9423 are provided on the sixth pipeline 942; the first control valve 93 can control the second pipeline 921 to be connected to the third pipeline 931 or to be connected to the fourth pipeline 932, and the second control valve 94 can control the fourth pipeline 932 to be connected to the fifth pipeline 941 or to be connected to the sixth pipeline 942.

[0122] The third control valve 95 is connected to the water outlet 41 of the riser through the seventh pipeline 951. The third control valve 95 can also be connected to the eighth pipeline 952 and the ninth pipeline 953 in an on-off manner. A filter 9511 and a cooler 9512 are sequentially arranged on the seventh pipeline 951 along the direction of fluid flow, and a second adjustable flow valve 9532 is arranged on the ninth pipeline 953. The third control valve 95 can control the seventh pipeline 951 to be connected to the eighth pipeline 952 or to be connected to the ninth pipeline 953.

[0123] The pipelines for injecting water into the drill string model 6, pressurizing, regulating flow and regulating temperature are set separately. Compared with the previous optional embodiment in which the pipelines are integrated into one inlet pipeline, each component can operate independently without affecting each other, which can increase the success rate of the test. In addition, when one component fails, it will not affect the operation of other components, which improves the reliability of the system.

[0124] In this preferred embodiment, it is further preferred that a rock particle inlet 531 is provided on the bottom side wall of the horizontal section 53 of the casing, and the hydraulic system 9 also includes a rock particle hydraulic source 96, which is connected to the rock particle inlet 531 in an on-off manner through a tenth pipeline 961, and a second flow meter 9614 and a third adjustable flow valve 9613 are provided on the tenth pipeline 961 for conveying rock particles.

[0125] Reference Fig.13 A first one-way valve 9112, a second one-way valve 9311, a third one-way valve 9321, a fourth one-way valve 9421, a fifth one-way valve 9521, a sixth one-way valve 9531 and a seventh one-way valve 9612 are respectively provided on the first pipeline 911, the third pipeline 931, the fourth pipeline 932, the sixth pipeline 942, the eighth pipeline 952, the ninth pipeline 953 and the tenth pipeline 961. The first one-way valve 9112 can allow the fluid to flow into the drill string model 6, the second one-way valve 9311 can allow the fluid to flow into the drill string model 6, the third one-way valve 9321 can allow the fluid to flow into the second control valve 94, the fourth one-way valve 9421 can allow the fluid to flow into the drill string model 6, the fifth one-way valve 9521 can allow the fluid to flow toward the third switch valve 9522, the sixth one-way valve 9531 can allow the fluid to flow toward the fourth switch valve 9533, and the seventh one-way valve 9612 can allow the fluid to flow toward the rock particle inlet 531.

[0126] The first control valve 93, the second control valve 94 and the third control valve 95 are all three-position four-way valves. The first switch valve 9111, the second switch valve 9211, the eighth pipeline 952, the ninth pipeline 953 and the tenth pipeline 961 are respectively provided with a first switch valve 9111, a second switch valve 9211, a third switch valve 9522, a fourth switch valve 9533 and a fifth switch valve 9611. The first switch valve 9111, the second switch valve 9211, the third switch valve 9522, the fourth switch valve 9533 and the fifth switch valve 9611 are all two-position two-way valves to control the on and off of each location.

[0127] Specifically, the water injection hydraulic source 91 includes a first water tank and a first hydraulic pump, the pressurized hydraulic source 92 includes a second water tank and a second hydraulic pump, and the rock particle hydraulic source 96 includes a liquid tank and a screw pump.

[0128] The three-position four-way valve and the two-position two-way valve are both solenoid valves. The three-position four-way valve has four interfaces, one of which is closed, and the other three interfaces are used to connect the three pipes connected to the control valve. The three-position four-way valve has a first working position (i.e. corresponding to Figure 1 The left position in the middle), the middle position and the second working position (i.e. Figure 1 By switching the three-position four-way valve to the left position or the right position, the corresponding two pipelines can be conveniently controlled to be connected. When the three-position four-way valve is in the middle position, the three pipelines connected to the three-position four-way valve are not connected to each other.

[0129] The first one-way valve 9112 is located between the first switch valve 9111 and the drill string water inlet 611, and is used to allow the fluid to flow into the drill string model 6. The second one-way valve 9311 is located between the pressure gauge 9312 and the first control valve 93, the first adjustable flow valve 9322 is located between the third one-way valve 9321 and the first flow meter 9323, and the first flow meter 9323 is arranged close to the second control valve 94. The heater 9422 is located between the fourth one-way valve 9421 and the thermometer 9423, and the thermometer 9423 is arranged close to the drill string water inlet 611. The fifth one-way valve 9521 is located between the third control valve 95 and the third switch valve 9522, and the sixth one-way valve 9531, the second adjustable flow valve 9532 and the fourth switch valve 9533 are arranged in sequence along the fluid flow direction. Corresponding water tanks can be connected to the ends of the fifth pipeline 941 and the sixth pipeline 942 away from the third control valve 95. The fifth switch valve 9611 , the seventh check valve 9612 , the third adjustable flow valve 9613 and the second flow meter 9614 are arranged in sequence from the rock particle hydraulic source 96 to the rock particle inlet 531 .

[0130] Generally, a first pilot relief valve 9212 is connected to the second pipeline 921 near the water injection hydraulic source 91 , and a second pilot relief valve 9615 is connected to the tenth pipeline 961 near the rock particle hydraulic source 96 .

[0131] Furthermore, the multifunctional offshore horizontal well drilling system simulation test device also includes a control device, which is electrically connected to the flow pump, the drive mechanism 2 and the hydraulic system 9. The control device is specifically electrically connected to the pump, valve, pressure gauge 9312, flow meter, thermometer 9423, heater 9422 and cooler 9512 in the hydraulic system 9 to control the actions of each component.

[0132] In more detail, the operation process using the hydraulic system 9 is as follows:

[0133] The specific steps of injecting water into the drill string model 6 are: adjust the first switch valve 9111 to the open position, adjust the third control valve 95 to the left position, and adjust the third switch valve 9522 to the open position. Then start the water injection hydraulic source 91 to inject water into the drill string model 6. Water flows in from the drill string water inlet 611, flows out from the small hole in the drill string end cover 64 to the inside of the casing model 5, then flows through the inside of the watertight pipe model 4, and finally flows out from the watertight pipe outlet 41. When water flows out from the outlet of the third switch valve 9522 to the water tank connected to the end of the eighth pipeline 952, adjust the first switch valve 9111 and the third switch valve 9522 to the off position, and adjust the third control valve 95 to the middle position. At this time, the water injection hydraulic source 91 stops working and the water injection is completed.

[0134] The specific steps of pressurizing the inside of the drill string model 6 are as follows: after the water injection is completed, the second switch valve 9211 is adjusted to the open position, and the first control valve 93 is adjusted to the left position. The second one-way valve 9311 prevents water from flowing back and plays a role in protecting the circuit. Then the pressurized hydraulic source 92 starts to work and injects water for pressurization. The pressure value in the hydraulic circuit (i.e., the third pipeline 931) is recorded by the pressure gauge 9312. When the pressure is increased to the expected value of the test, the pressurization is stopped. Subsequently, the second switch valve 9211 is adjusted to the off position, and the first control valve 93 is adjusted to the middle position.

[0135] The specific steps of adjusting the flow rate under a certain water pressure inside the drill string model 6 are as follows: after the drill string model 6 is pressurized, the second switch valve 9211 is adjusted to the open position, the first control valve 93 is adjusted to the right position, the second control valve 94 is adjusted to the left position, the third control valve 95 is adjusted to the right position, and the fourth switch valve 9533 is adjusted to the open position. The openings of the first adjustable flow valve 9322 and the second adjustable flow valve 9532 are set to be consistent. At this time, the pressurized hydraulic source 92 starts to work and injects water into the hydraulic circuit (i.e., the second pipeline 921, the fourth pipeline 932 and the fifth pipeline 941). The flow rate in the hydraulic circuit can be adjusted by adjusting the openings of the first adjustable flow valve 9322 and the second adjustable flow valve 9532 at the same time. The flow rate in the hydraulic circuit is recorded by the first flowmeter 9323. The third check valve 9321 and the sixth check valve 9531 can ensure that the water in the hydraulic circuit does not flow back to protect the circuit. After the test, the second switch valve 9211 is adjusted to the off position, the first control valve 93 is adjusted to the middle position, the second control valve 94 is adjusted to the middle position, and the third control valve 95 is adjusted to the middle position.

[0136] The specific steps of adjusting the temperature inside the drill string model 6 are as follows: adjust the second switch valve 9211 to the open position, adjust the first control valve 93 to the right position, adjust the second control valve 94 to the right position, and adjust the third control valve 95 to the right position. The pressurized hydraulic source 92 starts to work and injects water into the hydraulic circuit, and adjusts the temperature of the water in the hydraulic circuit (i.e., the sixth pipeline 942) by adjusting the heater 9422. The temperature of the water in the hydraulic circuit is measured by the thermometer 9423. The temperature of the water in the hydraulic circuit (i.e., the seventh pipeline 951) is reduced by the cooler 9512 to ensure that the hydraulic components work at a suitable temperature.

[0137] The specific steps of injecting rock particles into the casing model 5 are as follows: after the step of pressurizing the inside of the drill string model 6 is completed, the fifth switch valve 9611 is adjusted to the open position, the third control valve 95 is adjusted to the right position, and the fourth switch valve 9533 is adjusted to the open position. At this time, the spiral pump starts to work, and water with rock particles (called solid-liquid two-phase flow) is injected into the hydraulic circuit. The flow rate of the solid-liquid two-phase flow can be adjusted by adjusting the third adjustable flow valve 9613 and the second adjustable flow valve 9532. The flow rate of the solid-liquid two-phase flow can be measured by the second flowmeter 9614. The rock particles can be filtered out of the hydraulic circuit by the filter 9511, reducing the wear of the hydraulic circuit. Finally, the solid-liquid two-phase flow is injected into the casing model 5 through the rock particle inlet 531 and flows out from the water outlet 41 of the watertight pipe. After the test, the spiral pump is stopped. The fifth switch valve 9611 is adjusted to the off position, the third control valve 95 is adjusted to the middle position, and the fourth switch valve 9533 is adjusted to the off position.

[0138] The cleaning steps of the interior of the watertight pipe model 4, the interior of the casing model 5 and the interior of the drill string model 6 are as follows: adjust the second switch valve 9211 to the open position, adjust the first control valve 93 to the left position, adjust the third control valve 95 to the left position, and adjust the third switch valve 9522 to the open position. Then, the pressurized hydraulic source 92 starts to inject water, and the interior of the entire watertight pipe model 4, the interior of the casing model 5 and the interior of the drill string model 6 will be washed by a large flow of water, and the residual rock particles inside will be taken out.

[0139] In summary, the multifunctional offshore horizontal well drilling system simulation test device in this embodiment has the following advantages:

[0140] (1) By changing the extension displacement and extension period of the three hydraulic cylinders, the offshore platform model 3 can undergo lateral, longitudinal and heave motions, thereby simulating the vibration response of the offshore drilling system under the motion of the offshore platform.

[0141] (2) A test device is proposed, which can simulate the effects of bidirectional external and internal flows on offshore drilling systems, including the vortex-induced vibration behavior of external flows on the watertight pipe, and can perform friction tests on the drill string and casing under drill string vibration.

[0142] (3) A hydraulic control scheme is proposed, which can realize the pressure of any fluid inside the drilling system required for the test. It can also be used to conduct vibration response tests of the drill string and casing to solid-liquid two-phase flow with different flow rates, temperatures and solid contents inside the drilling system, and vibration response tests of the drill bit speed to the drill string.

[0143] (4) A bending preventer 7 composed of a spiral tube is proposed, which can prevent the watertight pipe from being bent too much, reduce the concentration of bending stress, increase the service life and facilitate disassembly and assembly. The bending preventer 7 can limit any bending angle of the watertight pipe.

[0144] (5) An anti-friction structure 8 is proposed to convert the static friction and sliding friction between the drill string and the casing into rolling friction, thereby reducing the wear of the drill string and the casing. In addition, the anti-friction structure 8 can be used to conduct anti-friction tests, and the wear mechanism of the drill string and the casing against the ocean current and the internal solid-liquid two-phase flow can be qualitatively and quantitatively studied when the anti-friction structure 8 is used.

[0145] (6) The entire test device is a vibration response and friction test simulation device for offshore horizontal well drilling systems in offshore drilling projects. It is a multifunctional vibration response and friction test device for offshore horizontal well systems under actual working conditions. The entire test device includes a water tank 1 and a test bench 11. The longitudinal hydraulic cylinder 22, the transverse hydraulic cylinder 21 and the vertical hydraulic cylinder 23 on the test bench 11 can be used to adjust the amplitude and period of the lateral displacement, longitudinal displacement and heave of the offshore platform. The anti-bending device 7 can protect the watertight pipe model 4 so that its bending angle is within a certain range. The high-speed camera distributed outside the water tank 1 can be used to record the vibration displacement of the watertight pipe model 4 and the drill string model 6. The anti-friction structure 8 is used to perform friction and anti-friction tests, and can also be used in actual projects to reduce the friction between the drill string and the casing. The drill string end cap 64, the transmission member 65, the push ring 652, the spring 657, the sealing ring, the casing end cap 54, and the motor constitute a simulated drill bit device. The simulated drill bit device can simulate the influence of drill bits with different speeds on the drill string model 6 by adjusting the speed of the motor. The hydraulic system 9 can be used to transport fluid and solid-liquid two-phase flow, can realize the pressure delivery of any fluid inside the drilling system required for the test, and can adjust the flow rate, temperature and solid content of the fluid inside the drilling system, so as to simulate the vibration response and friction response of the offshore horizontal well drilling system under various working conditions.

[0146] Furthermore, the present application also provides a multifunctional offshore horizontal well drilling system simulation test method, which uses the above-mentioned multifunctional offshore horizontal well drilling system simulation test device to conduct a test, and the multifunctional offshore horizontal well drilling system simulation test method includes:

[0147] S1. Assemble a multifunctional offshore horizontal well drilling system simulation test device;

[0148] S2, injecting fluid into the drill string water inlet 611, adjusting the test influencing factors, starting the test, and recording the vibration displacement of the riser model 4 and the drill string model 6 during the test;

[0149] The adjustment test influencing factors include: using the driving mechanism 2 to adjust the amplitude and period of the movement of the offshore platform model 3 in the vertical direction, the first horizontal direction and / or the second horizontal direction, and using the hydraulic system 9 to adjust the pressure, flow rate and / or temperature of the liquid in the drill string model 6;

[0150] S3, after the test, taking out the drill string model 6 after the test, and comparing the drill string model 6 after the test with the drill string model 6 before the test, so as to obtain the wear amount and wear position of the drill string model 6 after the test;

[0151] S4. Repeat steps S1-S3 and use different experimental influencing factors to conduct multiple groups of experiments.

[0152] The whole method is tested using the above-mentioned test device and has the same effect, which will not be repeated here.

[0153] Further, in step S2, adjusting the test influencing factors also includes injecting a fluid containing rock particles into the rock particle inlet 531 on the casing horizontal section 53 using the hydraulic system 9 and adjusting the rock particle content, flow rate, temperature and / or pressure of the fluid containing rock particles, and using the driving member 67 to drive the transmission member 65 rotatably connected to the drill string end cap 64 at the end of the drill string horizontal section 63 and adjusting the rotation speed of the driving member 67. Adjusting the test influencing factors may also include adjusting the pump speed of the flow pump. Adjusting the test influencing factors may also include changing the roughness of the inner wall of the casing model 5.

[0154] Furthermore, in step S1 , during the process of assembling the multifunctional offshore horizontal well drilling system simulation test device, a plurality of anti-friction structures 8 are sleeved between the drill string model 6 and the casing model 5 . The anti-friction structures 8 include a plurality of balls 83 and can be in rolling contact with the casing model 5 .

[0155] By simulating ocean currents and oscillating flows through a flow-making pump, driving the movement of the ocean platform model 3, adjusting the relevant parameters of the fluid in the drill string model 6, introducing rock particle fluid and adjusting the rotation speed of the driving member 67, it is possible to simulate vibration response tests under external ocean currents, ocean platform movement, internal fluid and drill bit vibration conditions. By introducing rock particles and adjusting relevant parameters, changing the roughness of the inner wall of the casing model 5 and whether to add an anti-friction structure 8, it is possible to simulate the friction test of wear between the drill string and the casing under different working conditions. It can more comprehensively and realistically simulate the working conditions of vibration and wear of the watertight pipe, drill string and casing in the marine environment, and more realistically simulate the influence of different platform movement directions, movement speeds and movement cycles on the offshore drilling system, the influence of different internal flow velocities, internal flow temperatures and internal flow pressures on the watertight pipe, drill string and casing, the influence of solid-liquid two-phase flow and different solid contents on the watertight pipe, drill string and casing, and the wear mechanism of various factors on the drill string and casing.

[0156] Further, the test method is illustrated below with a specific embodiment, and the implementation process of the test method is as follows:

[0157] Step 1: Press Figure 5 The test device is set up as shown. In order to study the friction mechanism and the anti-friction mechanism, the test is divided into two groups, one group is the test without the anti-friction structure 8, and the other group is the test with the anti-friction structure 8. When the test is conducted without the anti-friction structure 8, the anti-friction structure 8 is removed; when the test is conducted with the anti-friction structure 8, the anti-friction structure 8 is added.

[0158] Step 2: Adjust the factors that affect the friction test. For example, adjust the amplitude and period of the longitudinal, transverse and heave of the offshore platform model 3 by adjusting the elongation and elongation-shortening period of the longitudinal hydraulic cylinder 22, the transverse hydraulic cylinder 21 and the vertical hydraulic cylinder 23; adjust the rock particle content, flow rate, temperature and pressure of the solid-liquid two-phase flow; and adjust the speed of the motor to simulate the speed of different drill bits.

[0159] Step three, after the test starts, the vibration patterns of the riser model 4 and the drill string model 6 are photographed by a high-speed camera.

[0160] Step 4: After the test, the drill string model 6 is taken out and scanned with a 3D scanner. The scanned model is imported into Geomagic software (existing software, other software can also be used for comparative analysis as needed), and the model is compared with the untested drill string model 6 to compare the wear amount and wear position of the drill string model 6.

[0161] Step 5: After the data processing is completed, repeat the above steps to study the wear mechanism and anti-friction mechanism of the drill string and casing under different factors.

[0162] Furthermore, the multifunctional offshore horizontal well drilling system simulation test method also includes:

[0163] S5. Determine the factors affecting drill string wear based on multiple groups of tests;

[0164] S6. Fit the wear influencing factors of drill string wear and the wear amount of the drill string model to obtain a prediction model between the maximum wear depth of the drill string and the wear influencing factors of the drill string. The prediction model can be used to predict the wear depth of the drill string in actual working conditions.

[0165] Furthermore, the prediction model is: h = A p +A v +A d +A c +A t ;

[0166] Among them, A p =a1p 3 +b1p 2 +c1p+d1,A v =a2v 3 +b2v 2 +c2v+d2,A d =a3d 3 +b3d 2 +c3d+d3,A c =a4C 3 +b4C 2 +c4C+d4,A t =a5t3 +b5t 2 +c5t+d5;

[0167] h represents the maximum wear depth of the worn drill string under the action of various factors, p represents the internal fluid pressure of the worn drill string, v represents the fluid flow rate in the worn drill string, d represents the diameter of the rock particles in the worn drill string, C represents the content of rock particles in the fluid in the worn drill string, A represents the diameter of the rock particles in the worn drill string, p A represents the maximum wear of the drill string under the action of internal fluid pressure. v A represents the maximum wear of the drill string under the action of fluid flow rate. d A represents the maximum wear of the drill string under the effect of rock particle diameter. c A represents the maximum wear of the drill string under the influence of the rock particle content in the fluid. t It represents the maximum wear amount of the worn drill string under the action of fluid impact time. a1, b1, c1, d1, a2, b2, c2, d2, a3, b3, c3, d3, a4, b4, c4 and d4 are all coefficients.

[0168] Specifically, this embodiment further provides a method for predicting the maximum wear depth of a worn drill string based on the above-mentioned offshore horizontal well drilling system test method, and its main implementation process is:

[0169] The drill string wear factors considered in this embodiment are the internal fluid pressure p, the fluid flow rate v, the rock particle diameter d and the rock particle content C in the fluid.

[0170] First, the relationship between the wear amount and various factors is fitted. The fitting formula can be linear fitting, exponential fitting, logarithmic fitting or polynomial fitting. This embodiment uses polynomial fitting. Other fitting methods can also be used according to the test results. The formula for fitting each influencing factor is as follows:

[0171] A p =a1p 3 +b1p 2 +c1p+d1

[0172] A v =a2v 3 +b2v 2 +c2v+d2

[0173] A d =a3d 3 +b3d 2 +c3d+d3

[0174] A c =a4C 3 +b4C 2 +c4C+d4

[0175] A t =a5t 3 +b5t 2 +c5t+d5

[0176] Therefore, the maximum wear depth of the worn drill string under various factors is: h = A p +A v +A d +A c +A t .

[0177] The coefficient range in the above formula is These coefficients are empirical values ​​obtained from experiments, and can be set between 0.001 and 0.5 according to actual conditions. The above formula can be used to predict the wear depth of the drill string in actual engineering.

[0178] The above are only exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A multifunctional offshore horizontal well drilling system simulation test device, characterized in that: include: A vertically arranged water pool, wherein a middle plate is arranged at the bottom thereof and the interior of the water pool is divided into a water containing cavity at the upper part and a hollow cavity at the lower part; A flow pump is provided in the water containing chamber; A test bench is arranged on the top of the water pool, and a driving mechanism is arranged on the test bench; An ocean platform model, wherein the driving mechanism is connected to the top of the ocean platform model and can drive the ocean platform model to move in a vertical direction and in a first horizontal direction and a second horizontal direction perpendicular to each other; A riser model, the top of which is connected to the bottom of the offshore platform model, and a riser outlet is provided on the top of the riser model; A casing model, comprising a casing vertical section, a casing curved section, a casing horizontal section and a casing end cover connected in sequence, wherein the top of the casing vertical section is detachably connected to the bottom of the watertight pipe model; A drill string model is inserted into the watertight pipe model and the casing model; the drill string model comprises a drill string vertical section, a drill string curved section and a drill string horizontal section which are connected in sequence, the top of the drill string vertical section is connected to the bottom of the offshore platform model, and a drill string water inlet is provided at the top of the drill string vertical section; The hydraulic system can be connected to the water inlet of the drill string and the water outlet of the watertight pipe through corresponding pipelines, and can adjust the pressure, flow rate and / or temperature of the liquid in the drill string model.

2. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: A drill string end cover is also connected to the end of the horizontal section of the drill string, and a plurality of fluid holes are opened on the side wall of the drill string end cover. A transmission member is rotatably connected to the drill string end cover, and a driving member is also provided in the hollow cavity. The driving member can pass through the casing end cover and be connected to the transmission member to drive the transmission member to rotate.

3. The multifunctional offshore horizontal well drilling system simulation test device according to claim 2, characterized in that: A mounting hole is provided on the casing end cover, the first end of the transmission member is connected to the drill string end cover through a bearing, and the second end of the transmission member is inserted into the mounting hole; a convex ring is convexly provided on the outer wall of the first end of the transmission member, and a push ring, a first ring body and a second ring body are sequentially sleeved on the outside of the transmission member from the first end to the second end; A first annular flange is protruded from the outer wall of the end portion of the second ring body close to the first ring body, and the first flange can be combined with the bottom inner wall of the vertical section of the sleeve and the inner wall of the sleeve end cover to form a first sealing ring groove, and a first sealing ring is embedded in the first sealing ring groove; a second annular flange is protruded from the inner wall of the end portion of the first ring body close to the second ring body, one end of the push ring can be movably inserted in the first ring body and can be combined with the second flange to form a second sealing ring groove, and a second sealing ring is embedded in the second sealing ring groove; a plurality of push rods are axially spaced apart at the other end of the push ring, and the plurality of push rods can be movably inserted into a plurality of through holes on the convex ring, and a spring is sleeved on each of the push rods, and the two ends of the spring can respectively abut between the convex ring and the push ring.

4. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: A rock particle inlet is provided on the bottom side wall of the horizontal section of the casing, and the hydraulic system is also connected to the rock particle inlet through a corresponding pipeline to inject fluid containing rock particles into the annulus between the casing model and the drill string model.

5. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: There are two flow-generating pumps, and the flow-generating ports of the two flow-generating pumps are arranged back to back.

6. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: A camera is also provided outside the water pool for taking pictures of the riser model and the drill string model to record the displacement of the riser model and the drill string model.

7. The multifunctional offshore horizontal well drilling system simulation test device according to claim 6, characterized in that: The water pool is a transparent structure, the watertight pipe model is a transparent pipe, and an identification piece is provided on the outer wall of the watertight pipe model. The drill string model is a color pipe, and the color of the identification piece is different from that of the color pipe.

8. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: The driving mechanism includes a transverse hydraulic cylinder, a longitudinal hydraulic cylinder and a vertical hydraulic cylinder. One end of the transverse hydraulic cylinder is connected to the vertical hydraulic cylinder and can drive the vertical hydraulic cylinder to move horizontally along the first horizontal direction, and the first horizontal direction is parallel to the axial direction of the horizontal section of the drill string; one end of the longitudinal hydraulic cylinder is connected to the vertical hydraulic cylinder and can drive the vertical hydraulic cylinder to move horizontally along the second horizontal direction; the vertical hydraulic cylinder is connected to the top of the marine platform model and can drive the marine platform model to move up and down in the vertical direction.

9. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: A shaft sleeve is provided at the joint position between the bottom of the watertight pipe model and the top of the vertical section of the casing. The shaft sleeve is connected to the watertight pipe model and the vertical section of the casing through corresponding fasteners. A sealing ring is installed between the shaft sleeve and the mounting hole provided on the middle plate, and a waterproof sealant is provided at the connection between the shaft sleeve and the middle plate.

10. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: An anti-bending device is also sleeved on the outside of the watertight pipe, and the anti-bending device includes a mounting ring and a plurality of spiral rings. The mounting ring is connected to the bottom of the offshore platform model, and the top of each spiral ring is connected to the bottom of the mounting ring; the plurality of spiral rings are arranged side by side along a busbar and spirally wound around the vertical axis of the mounting ring, and adjacent spiral rings are arranged closely, and the bottom ends of the spiral rings are connected to adjacent spiral rings through clamps.

11. The multifunctional offshore horizontal well drilling system simulation test device according to claim 10, characterized in that: The spiral radius and number of turns of each point on the spiral center line corresponding to each spiral ring satisfy the following formula: Among them, y represents the spiral radius of each point on the spiral center line corresponding to the spiral ring, x represents the number of circles corresponding to each point on the spiral center line corresponding to the spiral ring, and a, b, c and d are all coefficients.

12. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: A plurality of anti-friction structures are sleeved axially at intervals outside the horizontal section of the drill string. The anti-friction structures include two fixed rings sleeved on the horizontal section of the drill string and arranged at intervals, and a spiral rib spirally wound around the axis of the horizontal section of the drill string. Both ends of the spiral rib are respectively connected to the two fixed rings. A plurality of rolling balls are sleeved on the spiral rib, and at least some of the balls can roll in contact with the inner wall of the horizontal section of the casing.

13. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: The hydraulic system includes a water injection hydraulic source, a pressurized hydraulic source, a first control valve, a second control valve and a third control valve. The water injection hydraulic source is connected to the drill string water inlet through a first pipeline in an on-off manner. The pressurized hydraulic source is connected to the first control valve in an on-off manner through a second pipeline. The first control valve is also connected to the drill string water inlet and the second control valve through a third pipeline and a fourth pipeline, respectively. The second control valve is also connected to the drill string water inlet through a fifth pipeline and a sixth pipeline, respectively. A pressure gauge is provided on the third pipeline, a first adjustable flow valve and a first flow meter are provided on the fourth pipeline, and a heater and a thermometer are provided on the sixth pipeline. The first control valve can control the second pipeline to be connected to the third pipeline or to the fourth pipeline, and the second control valve can control the fourth pipeline to be connected to the fifth pipeline or to the sixth pipeline. The third control valve is connected to the water outlet of the riser through the seventh pipeline. The third control valve can also be connected to the eighth pipeline and the ninth pipeline in an on-off manner. A filter and a cooler are sequentially arranged on the seventh pipeline along the fluid flow direction. A second adjustable flow valve is arranged on the ninth pipeline. The third control valve can control the seventh pipeline to be connected to the eighth pipeline or to the ninth pipeline.

14. The multifunctional offshore horizontal well drilling system simulation test device according to claim 13, characterized in that: A rock particle inlet is provided on the bottom side wall of the horizontal section of the casing, and the hydraulic system further comprises a rock particle hydraulic source, which is connected to the rock particle inlet in an on-off manner through a tenth pipeline, and a second flow meter and a third adjustable flow valve are provided on the tenth pipeline.

15. The multifunctional offshore horizontal well drilling system simulation test device according to claim 14, characterized in that: A first one-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a fifth one-way valve, a sixth one-way valve and a seventh one-way valve are respectively provided on the first pipeline, the third pipeline, the fourth pipeline, the sixth pipeline, the eighth pipeline, the ninth pipeline and the tenth pipeline.

16. The multifunctional offshore horizontal well drilling system simulation test device according to claim 14, characterized in that: The first control valve, the second control valve and the third control valve are all three-position four-way valves. The first pipeline, the second pipeline, the eighth pipeline, the ninth pipeline and the tenth pipeline are also respectively provided with a first switch valve, a second switch valve, a third switch valve, a fourth switch valve and a fifth switch valve. The first switch valve, the second switch valve, the third switch valve, the fourth switch valve and the fifth switch valve are all two-position two-way valves.

17. The multifunctional offshore horizontal well drilling system simulation test device according to claim 14, characterized in that: A first pilot-type relief valve is also connected to the second pipeline and close to the water injection hydraulic source, and a second pilot-type relief valve is also connected to the tenth pipeline and close to the rock particle hydraulic source.

18. The multifunctional offshore horizontal well drilling system simulation test device according to claim 1, characterized in that: The multifunctional offshore horizontal well drilling system simulation test device also includes a control device, which is electrically connected to the flow pump, the driving mechanism and the hydraulic system.

19. A multifunctional offshore horizontal well drilling system simulation test method, characterized in that: The test is conducted using the multifunctional offshore horizontal well drilling system simulation test device as described in any one of claims 1 to 18, and the multifunctional offshore horizontal well drilling system simulation test method comprises: S1. Assembling the multifunctional offshore horizontal well drilling system simulation test device; S2, injecting fluid into the water inlet of the drill string, starting the test, adjusting the test influencing factors, and recording the vibration displacement of the riser model and the drill string model during the test; The adjustment test influencing factors include: using a driving mechanism to adjust the amplitude and period of the movement of the offshore platform model in the vertical direction, the first horizontal direction and / or the second horizontal direction, and using a hydraulic system to adjust the pressure, flow rate and / or temperature of the liquid in the drill string model; S3, after the test, taking out the drill string model after the test, and comparing the drill string model after the test with the drill string model before the test to obtain the wear amount and wear position of the drill string model after the test; S4. Repeat steps S1-S3 and use different experimental influencing factors to conduct multiple groups of experiments.

20. The multifunctional offshore horizontal well drilling system simulation test method according to claim 19, characterized in that: In step S2, adjusting the test influencing factors also includes using a hydraulic system to inject a fluid containing rock particles into a rock particle inlet on the horizontal section of the casing and adjusting the rock particle content, flow rate, temperature and / or pressure of the fluid containing rock particles, and using a driving member to drive a transmission member rotatably connected to a drill string end cover at the end of the horizontal section of the drill string and adjusting the rotation speed of the driving member.

21. The multifunctional offshore horizontal well drilling system simulation test method according to claim 19, characterized in that: In step S1, during the process of assembling the multifunctional offshore horizontal well drilling system simulation test device, a plurality of anti-friction structures are sleeved between the drill string model and the casing model. The anti-friction structures include a plurality of balls and can be in rolling contact with the casing model.

22. The multifunctional offshore horizontal well drilling system simulation test method according to claim 19, characterized in that: The multifunctional offshore horizontal well drilling system simulation test method further comprises: S5. Determine the factors affecting drill string wear based on multiple groups of tests; S6. Fit the factors affecting drill string wear and the wear amount of the drill string model to obtain a prediction model between the maximum wear depth of the drill string and the factors affecting drill string wear.

23. The multifunctional offshore horizontal well drilling system simulation test method according to claim 22, characterized in that: The prediction model is: h = A p +A v +A d +A c +A t ; Among them, A p = a1p 3 + b1p 2 + c1p + d1, A v = a2v 3 + b2v 2 + c2v + d2, A d = a3d 3 + b3d 2 + c3d + d3, A c = a4C 3 + b4C 2 + c4C + d4, A t = a5t 3 + b5t 2 + c5t + d5; h represents the maximum wear depth of the worn drill string under the action of various factors, p represents the internal fluid pressure of the worn drill string, v represents the fluid flow rate in the worn drill string, d represents the diameter of the rock particles in the worn drill string, C represents the content of rock particles in the fluid in the worn drill string, A represents the diameter of the rock particles in the worn drill string, p Indicates the maximum wear of the drill string under the action of internal fluid pressure, A v A represents the maximum wear of the drill string under the action of fluid flow rate, d A represents the maximum wear of the drill string under the effect of rock particle diameter. c A represents the maximum wear of the drill string under the influence of the rock particle content in the fluid. t It represents the maximum wear amount of the worn drill string under the action of fluid impact time. a1, b1, c1, d1, a2, b2, c2, d2, a3, b3, c3, d3, a4, b4, c4 and d4 are all coefficients.

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