Flexible drill rod horizontal section drilling experiment device based on drilling fluid working condition

Abstract

According to the flexible drill rod horizontal section drilling experiment device based on the drilling fluid working condition, eddy current displacement sensors are fixed to the outer wall of a transparent sleeve which is horizontally arranged in the device, and the eddy current displacement sensors are perpendicular to each other; one end of the flexible drill rod is sequentially connected with a stepping motor and a hand wheel pressurizer in a motor displacement mechanism through an electromagnetic dynamic torque sensor, and the other end of the flexible drill rod is connected with a tail end pressure measurer; a flow meter and a drilling fluid barrel filled with drilling fluid and provided with an adjustable flow pump are connected in the conveying pipeline, and the two ends of the conveying pipeline are connected with the transparent sleeve to form a circulation loop. The electromagnetic dynamic torque sensor, the hand wheel pressure sensor, the tail end pressure sensor and the eddy current displacement sensor are sequentially connected with a data acquisition system and an upper computer through measuring cables. Visual and real-time observation of the working condition of the flexible drill rod in the horizontal section is achieved, and data reference can be provided for the flexible drill rod under the horizontal drilling condition.

Description

Technical Field

[0001] The invention belongs to the testing equipment for flexible drill pipes in oil drilling, and relates to an experimental device for horizontal section drilling of flexible drill pipes under drilling fluid conditions. Background Art

[0002] A horizontal well is a special well with a maximum well deviation angle reaching or approaching 90° (generally not less than 86°) and maintaining a certain length of horizontal section in the target formation. It is mainly used for the development of carbonate fractured reservoirs, oil reservoirs with gas caps or bottom water, thin-layer oil reservoirs, low-permeability oil reservoirs, heavy oil reservoirs, and highly water-cut artificial water injection oil reservoirs, etc. Although the cost of horizontal wells is higher than that of vertical wells, for non-fractured reservoirs, their production is approximately 3 times that of vertical wells, for reservoirs with natural fractures, the production can reach 12 times that of vertical wells, and for water-producing oilfields, the oil and gas recovery rate is much higher than that of vertical wells.

[0003] When a flexible drill pipe is used in ultra-short radius sidetracking horizontal well operations, it bears large stress mutations caused by alternating loads and is prone to form lateral vibrations of the drill pipe. Strong lateral vibrations are likely to cause problems such as drill tool failure and difficult control of the wellbore trajectory. At the same time, the drill pipe often encounters various resistances during drilling, is prone to self-locking phenomena in horizontal wellbores, resulting in a sharp increase in internal stress and easily causing damage to the drill pipe. The self-locking phenomenon of the drill pipe is not only related to the frictional force generated by contact and collision with the wellbore wall, but also has a very large relationship with the viscous frictional force generated by the drilling fluid on the drill tool.

[0004] How to verify the stability and mechanical properties of flexible drill pipes in the horizontal section is related to the improvement of the horizontal section extension ability of ultra-short radius horizontal wells and is also the key to improving oil recovery efficiency. It has become an urgent problem to be solved currently. Summary of the Invention

[0005] The invention provides an experimental device for horizontal section drilling of flexible drill pipes under drilling fluid conditions. By using this experimental device, a horizontal section of a horizontal well with drilling fluid flow is simulated, and the stability and mechanical properties of the flexible drill pipe are tested in this horizontal section. The lateral vibration displacement, torque, and variation of the drill pressure of the drill tool during drilling are measured, collected, and analyzed. Explore the stability and mechanical conditions of the flexible drill pipe during drilling, further reveal the action mechanism of flowing drilling fluid on the moving flexible drill pipe, and provide experimental data support for subsequent drilling process parameter control, drill tool cutting mechanics analysis, and flexible drill pipe trajectory prediction.

[0006] The technical solution of the present invention is: a flexible drill pipe horizontal section drilling experiment device based on drilling fluid working conditions, including a stepping motor, a data acquisition system and a host computer, wherein: the drilling experiment device is further provided with a handwheel pressure applicator, a motor displacement mechanism, an end pressure gauge, a transparent sleeve and an adjustable flow pump; the outer wall of the transparent sleeve supported by a sleeve bracket and horizontally placed is fixed with eddy current displacement sensors installed perpendicular to each other, and sealing end caps are installed at both ends of the transparent sleeve; the flexible drill pipe composed of multiple flexible short sections is horizontally placed in the transparent sleeve, and the ends of the flexible drill pipe protrude from the sealing end caps at both ends, and one end is connected to the stepping motor and the handwheel pressure applicator in the motor displacement mechanism in sequence through an electromagnetic dynamic torque sensor, and the other end is connected to the end pressure gauge; handwheel pressure sensors and end pressure sensors are respectively installed in the handwheel pressure applicator and the end pressure gauge; a flow meter and a drilling fluid barrel filled with drilling fluid and equipped with an adjustable flow pump are connected in the conveying pipeline, and both ends of the conveying pipeline are connected to the transparent sleeve to form a circulation loop; the electromagnetic dynamic torque sensor, the handwheel pressure sensor, the end pressure sensor and the eddy current displacement sensor are all connected to the data acquisition system and the host computer in sequence through measurement cables.

[0007] Preferably, the motor displacement mechanism is further provided with a guide rail, a guide rail bracket, a motor fixing seat and a movable motor base. The motor fixing seat is fixed on the movable motor base, the stepping motor is fixedly connected to the motor fixing seat, and the movable motor base can move along the guide rail; There are two guide rails, and both ends of the two guide rails are fixedly connected to the guide rail brackets fixed on the backing plate respectively.

[0008] Preferably, the movable motor base is connected to the two guide rails through sliders. The sliders are block-shaped bodies provided with guide rail connection holes or connection grooves. The sliders can be sleeved outside the guide rails and can be fixed to the lower end surface of the movable motor base through bolts. The guide rail connection holes or connection grooves in the sliders match the external structures of the guide rails; the movable motor base is an L-shaped plate body, a reinforcing plate is provided between the horizontal plate and the vertical plate of the movable motor base, and a threaded hole capable of being connected to the handwheel pressure applicator is provided in the vertical plate.

[0009] Preferably, the handwheel pressure applicator further comprises a handwheel, a handwheel screw slide, a sensor fixing plate, a handwheel pressure sleeve and a damping spring I. The handwheel screw slide is provided with a sensor fixing table and a centering rod, wherein: the sensor fixing table and the centering rod are arranged in the groove of the handwheel screw slide. The sensor fixing table is provided with a handwheel screw threaded connection hole and a centering rod through hole. The handwheel arranged outside the handwheel screw slide is fixedly connected with one end of the handwheel screw connected in the sensor fixing table; the sensor fixing plate is fixedly connected with the sensor fixing table by bolts. One end of the handwheel pressure sensor is connected with the sensor fixing plate by bolts, and the other end is connected with the end plate of the handwheel pressure sleeve by bolts; the damping spring I is sleeved outside the handwheel pressure sleeve and can abut against the rear end face of the end plate of the handwheel pressure sleeve. The rear end of the handwheel pressure sleeve can be connected with the threaded hole in the vertical plate of the movable motor base.

[0010] Preferably, the handwheel screw slide in the handwheel pressure applicator is connected with the backing plate fixed on the fixed foundation by bolts; the centering rod is arranged in the sensor fixing tables on both sides of the handwheel screw.

[0011] Preferably, the end pressure gauge further comprises a support plate, an end pressure measuring sleeve, a damping spring II, a bearing flange and a thrust bearing, wherein: the end pressure sensor is fixedly connected between the end plate of the end pressure measuring sleeve and the vertical plate of the support plate by bolts; the bottom plate of the end pressure measuring sleeve is fixedly connected in the fixed foundation, and a reinforcing plate is arranged between the bottom plate and the vertical plate of the end pressure measuring sleeve; the bearing flange is connected with the thrust bearing by bolts. The other end of the end pressure measuring sleeve tube body sleeved with the damping spring II passes through the bearing flange and is installed in the thrust bearing; the thrust bearing is fixedly connected with the flexible drill pipe.

[0012] Preferably, the transparent sleeve is made of acrylic material. The sealing end caps installed at both ends of the transparent sleeve are provided with an outer end cap, an outer sealing cap, a sealing ring, an inner sealing cap, a sealing member, a circlip and a sealing bearing, wherein: both the outer end cap and the outer sealing cap are cylindrical bodies with a T-shaped longitudinal section. The outer sealing cap is equipped with a sealing ring on the outer circumference of its lower part. The outer sealing cap is sleeved outside the outer wall of the lower part of the outer end cap and is connected with the outer end cap by bolts. The outer diameter of the outer sealing cap is consistent with the inner diameter of the end of the transparent sleeve and is equipped with more than one sealing ring, and the sealing between the outer sealing cap and the transparent sleeve is realized through the outer sealing cap and the sealing ring; two circlip assembly grooves are arranged in the central hole of the outer sealing cap, and a sealing bearing is installed in the central hole between the two circlip assembly grooves; the inner sealing cap is a cylindrical body with a T-shaped longitudinal section. The lower cylindrical body is installed in the central hole of the outer end cap, and the outer circular step of its upper part is clamped in the upper end face of the outer end cap. The aperture of the central hole of the inner sealing cap is consistent with the outer diameter of the flexible drill pipe; more than one sealing member is installed in the central hole of the inner sealing cap.

[0013] Preferably, the electromagnetic dynamic torque sensor is fixed in a fixed bracket and fixedly connected to a fixed foundation through the fixed bracket; the rotating shafts at both ends of the electromagnetic dynamic torque sensor are respectively connected to the flexible drill pipe and the output shaft of the stepping motor through couplings.

[0014] Preferably, the eddy current displacement sensor is fixed in an eddy current displacement sensor bracket. Sensor fixing holes are provided at the top and both sides of the eddy current displacement sensor bracket. The eddy current displacement sensor bracket is connected to the fixed foundation by bolts; according to the test requirements for the flexible drill pipe, a magnetic conductive element is pasted on the outside of the flexible drill pipe corresponding to the eddy current displacement sensor; the eddy current displacement sensor is clamped in the eddy current sensor bracket by nuts on both sides of the sensor fixing holes.

[0015] Preferably, the sleeve bracket is provided with an upper sleeve bracket and a lower sleeve bracket. Arc-shaped grooves are provided in both the upper sleeve bracket and the lower sleeve bracket, and the inner circle formed by the arc-shaped grooves in the upper sleeve bracket and the lower sleeve bracket after being butted by bolts conforms to the outer circle of the transparent sleeve; the lower sleeve bracket is fixedly connected to the fixed foundation by bolts.

[0016] The remarkable usage effect of the present invention lies in that: the present invention is an experimental device for the drill pressure, torque and lateral vibration displacement of a flexible drill pipe working in a drilling fluid flow environment with different viscosities and different flow rates. By means of an adjustable flow pump installed in the drilling fluid bucket, a circulation loop is formed between the delivery pipeline and the transparent sleeve. The flexible drill pipe in the horizontal section, that is, in the transparent sleeve, is drilled under the working condition with drilling fluid flowing, making the test of the flexible drill pipe by the experimental device closer to the downhole working environment, so that the test data is more real and credible. It can provide data reference for the research object - the flexible drill pipe under horizontal drilling conditions to avoid self-locking failure and normal stable operation caused by alternating loads.

[0017] The device of the present invention takes the flexible drill pipe as the research object. The two ends of the flexible drill pipe are respectively connected to the end pressure sensor, the electromagnetic dynamic torque sensor and the handwheel pressure sensor. The flexible drill pipe is horizontally placed in the transparent sleeve. Sealing end caps equipped with seals are installed at both ends of the transparent sleeve, which can effectively prevent the leakage of drilling fluid during the flowing process. One end of the flexible drill pipe is connected to the stepping motor through a coupling, and the other end is connected to the thrust bearing in the end pressure gauge; the eddy current displacement sensor is placed outside the transparent sleeve, and a magnetic conductive element is pasted at a specified position on the flexible drill pipe to measure the lateral displacement at the specified position. The drilling fluid enters from one end of the transparent sleeve through the delivery pipeline by means of the adjustable flow pump and flows out from the other end, forming a circulation loop; a flowmeter is installed in the delivery pipeline to monitor the flow data in real time. Its specific advantages are as follows: 1. Visualization and real-time observation of the working conditions of the flexible drill pipe in the horizontal section are realized through this device; 2. The pressure, torque and lateral vibration of the flexible drill pipe can be measured in real time through this device, and the collected data can be transmitted to the upper computer through the data acquisition system for data modeling; 3. The relevant drilling process parameters of the flexible drill pipe can be adjusted steplessly through this device to explore the influence of the drilling process parameters on the stability and dynamic characteristics of the flexible drill pipe.

[0018] The present invention can further reveal the action mechanism of the flowing drilling fluid on the moving flexible drill pipe, and provide experimental data support for the subsequent control of drilling process parameters, the analysis of drill cutting mechanics and the prediction of the flexible drill pipe trajectory. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings: Figure 1 Schematic diagram of the overall working principle of the device of the present invention; Figure 2 Schematic diagram of the overall design structure of the device of the present invention; Figure 3 Figure 2 Schematic diagram of the structure of the middle sleeve bracket; Figure 4 Schematic diagram of the installation method of the middle flexible drill pipe; Figure 5 Cross-sectional view of the sealing end cover; Figure 6 For Figure 5 Schematic diagram of the structural analysis of; Figure 7 Schematic diagram of the placement method of the eddy current displacement sensor; Figure 8 Schematic diagram of the fixing method of the stepping motor; Figure 9 Schematic diagram of the connection method of the electromagnetic dynamic torque sensor; Figure 10 Schematic diagram of the structure of the handwheel pressure applicator; Figure 11 Schematic diagram of the structure of the end pressure gauge; Figure 12 Schematic diagram of the circulation mode of the drilling fluid; In the figure: handwheel pressure applicator 1, handwheel screw slide 101, sensor fixing plate 102, handwheel pressure sensor 103, handwheel pressure sleeve 104, damping spring 1 105, sensor fixing table 106, centralizer 107; Motor displacement mechanism 2, guide rail bracket 201, guide rail 202, motor fixing seat 203, movable motor base 204; Stepper motor 3, coupling 4, electromagnetic dynamic torque sensor 5, flexible drill pipe 6; Sealing end cover 7, outer end cover 701, outer sealing cover 702, sealing ring 703, inner sealing cover 704, seal 705, circlip 706, sealed bearing 707; Transparent sleeve 8; Sleeve bracket 9, upper sleeve bracket 901, lower sleeve bracket 902; Eddy current displacement sensor 10, eddy current displacement sensor bracket 11; End pressure gauge 12, support plate 1201, end pressure sensor 1202, end pressure measuring sleeve 1203, damping spring II 1204, bearing flange 1205, thrust bearing 1206; Delivery pipeline 13, flowmeter 14, adjustable flow pump 15, drilling fluid barrel 16, backing plate 17, fixed foundation 18, data acquisition system 19, upper computer 20. Specific implementation mode

[0020] The attached drawings are only for reference and illustration, and are not intended to limit the protection scope of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, in the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0023] See Figures 1 to 12, A flexible drill pipe horizontal section drilling experiment device based on drilling fluid working conditions, including a stepping motor 3, a data acquisition system 19 and a host computer 20, where: The drilling experiment device is also provided with a handwheel pressure booster 1, a motor displacement mechanism 2, an end pressure gauge 12, a transparent sleeve 8 and an adjustable flow pump 15; The outer wall of the horizontally placed transparent sleeve 8 supported by a sleeve bracket 9 is fixed with eddy current displacement sensors 10 installed perpendicular to each other, and sealing end caps 7 are installed at both ends of the transparent sleeve 8; A flexible drill pipe 6 composed of multiple flexible short sections is horizontally placed in the transparent sleeve 8, and the ends of both ends of the flexible drill pipe 6 protrude from the sealing end caps 7, and one end is connected to the stepping motor 3 and the handwheel pressure booster 1 in the motor displacement mechanism 2 in sequence through an electromagnetic dynamic torque sensor 5, and the other end is connected to the end pressure gauge 12; A handwheel pressure sensor 103 and an end pressure sensor 1202 are respectively installed in the handwheel pressure booster 1 and the end pressure gauge 12; A flowmeter 14 and a drilling fluid barrel 16 filled with drilling fluid and equipped with an adjustable flow pump 15 are connected in the conveying pipeline 13, and both ends of the conveying pipeline 13 are connected to the transparent sleeve 8 to form a circulation loop; The electromagnetic dynamic torque sensor 5, the handwheel pressure sensor 103, the end pressure sensor 1202 and the eddy current displacement sensor 10 are all connected to the data acquisition system 19 and the host computer 20 in sequence through measurement cables.

[0024] In the present invention, the eddy current displacement sensors 10 installed perpendicular to each other can measure the lateral vibration of the flexible drill pipe 6 caused by alternating loads. The device of the present invention simulates the horizontal section of a horizontal well through the transparent sleeve 8, and conveys drilling fluid to the transparent sleeve 8 through the conveying pipeline 13 and the drilling fluid barrel 16 equipped with an adjustable flow pump 15 to simulate the horizontal section with drilling fluid flow. The flexible drill pipe 6 placed in the transparent sleeve 8 is tested for stability and mechanical properties through the electromagnetic dynamic torque sensor 5, the handwheel pressure sensor 103, the end pressure sensor 1202 and the vertically arranged eddy current displacement sensor 10, and the lateral vibration displacement, torsion and change of drilling pressure of the flexible drill pipe 6 itself during the drilling process are measured, collected and analyzed by the data acquisition system 19 and the host computer 20.

[0025] Through the present invention, the stability and mechanical conditions of the flexible drill pipe 6 during the drilling process can be explored, and the action mechanism of the flowing drilling fluid on the moving flexible drill pipe 6 can be further revealed. Its test data can be used for subsequent drilling process parameter control, drill cutting mechanics analysis and flexible drill pipe trajectory prediction.

[0026] The present invention is an experimental device for testing drilling pressure, torque and lateral vibration displacement of a flexible drill pipe 6 working in a drilling fluid flow environment with different viscosities and flow rates. The drilling fluid forms a circulation loop between the delivery pipeline 13 and the transparent casing 8 through an adjustable flow pump 15 installed in a drilling fluid barrel 16. The flexible drill pipe 6 in the horizontal section, i.e., the transparent casing 8, is drilled under a working condition with drilling fluid flow, so that the test of the flexible drill pipe 6 by the experimental device is closer to the downhole working environment, thereby making the test data more real and reliable. It can provide data reference for the flexible drill pipe under horizontal drilling conditions to avoid self-locking damage caused by alternating loads and normal and stable operation.

[0027] Based on the above embodiment 1, the present invention also has the following embodiments: A preferred embodiment: See Figure 2 and Figure 8 , the motor shift mechanism 2 is also provided with a guide rail 202, a guide rail bracket 201, a motor fixing seat 203 and a movable motor base 204, the motor fixing seat 203 is fixed on the movable motor base 204, the stepper motor 3 is fixedly connected to the motor fixing seat 203, and the movable motor base 204 can move along the guide rail 202; there are two guide rails 202, and the two ends of the two guide rails 202 are respectively fixedly connected to the guide rail bracket 201 fixed on the pad 17.

[0028] The stepper motor 3 fixed on the movable motor base 204 through the motor fixing seat 203 can move with the movement of the movable motor base 204 because it is connected to the hand wheel pressurizer 1.

[0029] A preferred embodiment: See Figure 2 and Figure 8 The movable motor base 204 is connected to the two guide rails 202 through a slider, which is a block with a guide rail connection hole or connection groove. The slider can be inserted into the outside of the guide rail 202 and can be fixed to the lower end surface of the movable motor base 204 by bolts. The guide rail connection hole or connection groove in the slider is consistent with the external structure of the guide rail 202; the movable motor base 204 is an L-shaped plate, and a reinforcement plate is provided between the horizontal plate and the vertical plate of the movable motor base 204, and a threaded hole that can be connected to the handwheel pressurizer 1 is provided in the vertical plate.

[0030] Preferred embodiment: The handwheel pressure applicator 1 further includes a handwheel, a handwheel screw slide 101, a sensor fixing plate 102, a handwheel pressure application sleeve 104, and a first damping spring 105. The handwheel screw slide 101 is provided with a sensor fixing platform 106 and a centering rod 107, where: The sensor fixing platform 106 and the centering rod 107 are arranged in the groove of the handwheel screw slide 101. The sensor fixing platform 106 is provided with a handwheel screw threaded connection hole and a centering rod through hole. The handwheel arranged outside the handwheel screw slide 101 is fixedly connected to one end of the handwheel screw connected in the sensor fixing platform 106; The sensor fixing plate 102 is fixedly connected to the sensor fixing platform 106 by bolts. One end of the handwheel pressure sensor 103 is connected to the sensor fixing plate 102 by bolts, and the other end is connected to the end plate of the handwheel pressure application sleeve 104 by bolts; The first damping spring 105 is sleeved outside the handwheel pressure application sleeve 104 and can abut against the rear end face of the end plate of the handwheel pressure application sleeve 104. The rear end of the handwheel pressure application sleeve 104 can be connected to the threaded hole in the vertical plate of the movable motor base 204.

[0031] When the handwheel is rotated to drive the handwheel screw slide 101, it will drive the sensor fixing plate 102 and the handwheel pressure application sleeve 104 to move forward; At this time, the handwheel pressure sensor 103 monitors the magnitude of the applied pressure. The handwheel pressure application sleeve 104 is threadedly connected to the threaded hole on the movable motor base 204, and the first damping spring 105 presses against the side wall of the movable motor base 204, applying pressure to the motor displacement mechanism 2, and then transmitting the pressure to the flexible drill pipe 6, achieving the effect of manually applying pressure to the flexible drill pipe 6.

[0032] Preferred embodiment: Refer to Figure 2 and Figure 10 , the handwheel screw slide 101 in the handwheel pressure applicator 1 is connected to the backing plate 17 fixed on the fixed foundation 18 by bolts; The centering rod 107 is arranged in the sensor fixing platforms 106 on both sides of the handwheel screw.

[0033] Preferred embodiment: The end pressure gauge 12 further includes a support plate 1201, an end pressure measurement sleeve 1203, a second damping spring 1204, a bearing flange 1205, and a thrust bearing 1206, where: The end pressure sensor 1202 is fixedly installed between the end plate of the end pressure measurement sleeve 1203 and the vertical plate of the support plate 1201 by bolts; The bottom plate of the end pressure measurement sleeve 1203 is fixedly connected to the fixed foundation 18 by bolts. A reinforcing plate is provided between the bottom plate and the vertical plate of the end pressure measurement sleeve 1203; The bearing flange 1205 is connected to the thrust bearing 1206 by bolts. The other end of the tube body of the end pressure measurement sleeve 1203 sleeved with the second damping spring 1204 passes through the bearing flange 1205 and is installed in the thrust bearing 1206; The thrust bearing 1206 is fixedly connected to the flexible drill pipe 6.

[0034] The pressure measurement principle is as follows: The thrust bearing 1206 is fixedly connected to the flexible drill pipe 6, and can transmit the pressure received by the rotating flexible drill pipe 6 to the end pressure sensor 1202, and at the same time will not cause the end pressure sensor 1206 to generate rotational motion. The pressure received by the flexible drill pipe 6 during movement is often non-linear and unstable, and the damping spring II 1204 can accurately transmit the unstable pressure through its own deformation.

[0035] A preferred embodiment: Refer to Figure 5 and Figure 6 , the transparent sleeve 8 is made of acrylic material, and the sealing end caps 7 installed at both ends of the transparent sleeve 8 are provided with an outer end cap 701, an outer sealing cover 702, a sealing ring 703, an inner sealing cover 704, a seal 705, a snap ring 706 and a sealing bearing 707, wherein: both the outer end cap 701 and the outer sealing cover 702 are cylindrical bodies with a T-shaped longitudinal section, the lower outer circle of the outer sealing cover 702 is equipped with a sealing ring 703, the outer sealing cover 702 is sleeved outside the lower outer wall of the outer end cap 701 and is connected to the outer end cap 701 by bolts, the outer diameter of the outer sealing cover 702 is consistent with the inner diameter of the end of the transparent sleeve 8 and is equipped with more than one sealing ring 703, and the sealing between the outer sealing cover 702 and the transparent sleeve 8 is realized through the outer sealing cover 702 and the sealing ring 703; two snap ring assembly grooves are provided in the central hole of the outer sealing cover 702, and a sealing bearing 707 is installed in the central hole between the two snap ring assembly grooves to play a limiting role for the sealing bearing 707; the inner sealing cover 704 is a cylindrical body with a T-shaped longitudinal section, the lower cylindrical body is installed in the central hole of the outer end cap 701 and the upper outer circular step is stuck in the upper end face of the outer end cap 701, and the aperture of the central hole of the inner sealing cover 704 is consistent with the outer diameter of the flexible drill pipe 6; more than one seal 705 is installed in the central hole of the inner sealing cover 704 to realize the sealing of the flexible drill pipe 6.

[0036] The outer end cap 701 in the sealing end cap 7 is made of metal material and can withstand the impact force brought by the movement of the flexible drill pipe 6. It is fixedly connected to the outer sealing cover 702 by bolts, and more than one sealing ring 703 is sleeved outside the outer sealing cover 702 to realize the sealing between the outer sealing cover 702 and the inner wall of the transparent sleeve 8. Two snap rings 706 are embedded in the snap ring assembly grooves of the outer end cap 701 to play a limiting role. The sealing bearing 707 is installed between the two snap rings 706. More than one seal 705 is embedded in the inner sealing cover 704, and a better sealing effect can be achieved.

[0037] A preferred embodiment: Refer to Figure 2 and Figure 9The electromagnetic dynamic torque sensor 5 is fixed in the fixed bracket and fixedly connected to the fixed foundation 18 through the fixed bracket; the rotating shafts at both ends of the electromagnetic dynamic torque sensor 5 are respectively connected to the flexible drill rod 6 and the output shaft of the stepper motor 3 through the coupling 4. See Figure 4 , the flexible drill rod 6 formed by assembling multiple flexible short sections has multiple degrees of freedom. The front end of the flexible drill rod 6 extends out of the transparent sleeve 8 through the sealed end cover 7, and then is connected to the electromagnetic dynamic torque sensor 5 through the coupling 4, so that its torque and speed can be measured; the end of the flexible drill rod 6 also extends out of the transparent sleeve 8 through the sealed end cover 7, and then is connected to the end pressure gauge 12 through the thrust bearing 1206, so that its end pressure can be measured.

[0038] A preferred embodiment: See Figure 2 and Figure 7 , the eddy current displacement sensor 10 is fixed in the eddy current displacement sensor bracket 11, the top and both sides of the eddy current displacement sensor bracket 11 are provided with sensor fixing holes, and the eddy current displacement sensor bracket 11 is connected to the fixed foundation 18 by bolts; according to the test requirements of the flexible drill rod 6, the magnetic conductive element is pasted on the outside of the flexible drill rod 6 corresponding to the eddy current displacement sensor 10; the eddy current displacement sensor 10 is clamped in the eddy current sensor bracket 11 by nuts on both sides of the sensor fixing hole.

[0039] The measuring points of the eddy current displacement sensor 10 can be arranged arbitrarily, and the lateral vibration displacement of each flexible short section can be measured according to the needs. Two eddy current displacement sensors 10 are arranged vertically at each measuring point, and the lateral and longitudinal displacements of the flexible drill rod 6 can be measured respectively. The eddy current displacement sensor 10 can measure the flexible drill rod 6 through the transparent sleeve 8 made of acrylic. Because the eddy current displacement sensor 10 mainly measures the displacement through the skin effect of the current, and the acrylic material is not magnetic, it can be measured through the transparent sleeve 8.

[0040] A preferred embodiment: See Figure 2 and Figure 3 , the sleeve bracket 9 is provided with a sleeve upper bracket 901 and a sleeve lower bracket 902, and arc grooves are provided in the sleeve upper bracket 901 and the sleeve lower bracket 902, and the inner circle formed by the arc grooves in the sleeve upper bracket 901 and the sleeve lower bracket 902 after being connected by bolts is consistent with the outer circle of the transparent sleeve 8; The sleeve lower bracket 902 is fixedly connected to the fixed foundation 18 by bolts.

[0041] The working principle and process of the device of the present invention are as follows: After all components are installed, pressure is applied to the motor displacement mechanism 2 through the handwheel pressure applicator 1. Since the handwheel pressure sensor 103 is installed in the handwheel pressure applicator 1, the pressure on the flexible drill pipe 6 can be measured in real time through the handwheel pressure sensor 103, and the magnitude of the applied pressure can be adjusted according to experimental needs. At the same time, the end pressure gauge 12 abuts against the flexible drill pipe 6. After the initial conditions are set, the stepping motor 3 is started, and the torque is transmitted to the flexible drill pipe 6 through the coupling 4 and the electromagnetic dynamic torque sensor 5, driving the flexible drill pipe 6 to rotate. At the same time, the prepared drilling fluid is contained in the drilling fluid barrel 16, and the flow rate is adjusted as required by the adjustable flow pump 15, so that the drilling fluid flows through the conveying pipeline 13, enters from one end of the transparent sleeve 8 and flows out from the other end, forming a circulation loop.

[0042] During the test, the handwheel pressure sensor 103, the end pressure sensor 1202 and the eddy current displacement sensor 10 measure the lateral vibration displacement, pressure and torque of the flexible drill pipe 6, and the measured data is transmitted to the upper computer 20 through the data acquisition system 19 for visual data modeling, so as to facilitate subsequent analysis by researchers.

[0043] The above-described embodiments are only typical embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and inspiration of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and concept of the creation of the present invention shall be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions, comprising a stepping motor (3), a data acquisition system (19) and a host computer (20), wherein: The drilling experimental device is also provided with a handwheel pressurizer (1), a motor displacement mechanism (2), a terminal pressure gauge (12), a transparent sleeve (8) and an adjustable flow pump (15); the outer wall of the transparent sleeve (8) supported by a sleeve bracket (9) and placed horizontally is fixed with eddy current displacement sensors (10) installed vertically to each other, and both ends of the transparent sleeve (8) are equipped with sealing end covers (7); a flexible drill rod (6) composed of multiple flexible short sections is placed horizontally in the transparent sleeve (8), the ends of both ends of the flexible drill rod (6) are exposed from the sealing end covers (7) and one end is connected to the stepping motor (3) in the motor displacement mechanism (2) and the handwheel pressurizer (1) in sequence through the electromagnetic dynamic torque sensor (5). The handwheel pressure sensor (103) and the terminal pressure sensor (1202) are respectively installed in the handwheel pressurizer (1) and the terminal pressure sensor (12); the delivery pipeline (13) is connected to a flow meter (14) and a drilling fluid barrel (16) filled with drilling fluid and equipped with an adjustable flow pump (15); both ends of the delivery pipeline (13) are connected to the transparent sleeve (8) to form a circulation loop; the electromagnetic dynamic torque sensor (5), the handwheel pressure sensor (103), the terminal pressure sensor (1202) and the eddy current displacement sensor (10) are sequentially connected to the data acquisition system (19) and the host computer (20) through measuring cables.

2. A flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 1, characterized in that: The motor shifting mechanism (2) is further provided with a guide rail (202), a guide rail bracket (201), a motor fixing seat (203) and a movable motor base (204); the motor fixing seat (203) is fixed on the movable motor base (204); the stepping motor (3) is fixedly connected to the motor fixing seat (203); and the movable motor base (204) is movable along the guide rail (202); two guide rails (202) are provided, and the two ends of the two guide rails (202) are respectively fixedly connected to the guide rail bracket (201) fixed on the pad (17).

3. A flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 2, characterized in that: The movable motor base (204) is connected to the two guide rails (202) via a slider, the slider is a block provided with a guide rail connection hole or a connection groove, the slider can be inserted into the outside of the guide rail (202) and can be fixed to the lower end surface of the movable motor base (204) via bolts, the guide rail connection hole or the connection groove in the slider is consistent with the external structure of the guide rail (202); the movable motor base (204) is an L-shaped plate body, a reinforcement plate is provided between the horizontal plate and the vertical plate of the movable motor base (204), and a threaded hole capable of being connected to the handwheel pressurizer (1) is provided in the vertical plate.

4. A flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 3, characterized in that: The handwheel pressurizer (1) is further provided with a handwheel, a handwheel screw slide (101), a sensor fixing plate (102), a handwheel pressure sleeve (104) and a damping spring (105); the handwheel screw slide (101) is provided with a sensor fixing platform (106) and a straightening rod (107); wherein: the sensor fixing platform (106) and the straightening rod (107) are arranged in a groove of the handwheel screw slide (101); a handwheel screw threaded connection hole and a straightening rod through hole are provided in the sensor fixing platform (106); a handwheel arranged outside the handwheel screw slide (101) is connected to the sensor fixing platform (107); The sensor fixing plate (102) is fixedly connected to the sensor fixing platform (106) by bolts, one end of the handwheel pressure sensor (103) is connected to the sensor fixing plate (102) by bolts, and the other end is connected to the end plate of the handwheel pressure sleeve (104) by bolts; the damping spring (105) is sleeved on the outside of the handwheel pressure sleeve (104) and can be pressed against the rear end surface of the end plate of the handwheel pressure sleeve (104), and the rear end of the handwheel pressure sleeve (104) can be connected to the threaded hole in the vertical plate of the movable motor base (204).

5. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 4 is characterized in that: The handwheel screw slide (101) in the handwheel pressurizer (1) is connected to a pad (17) fixed on a fixed foundation (18) via bolts; the straightening rod (107) is arranged in the sensor fixing platform (106) on both sides of the handwheel screw.

6. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 1 is characterized in that: The terminal pressure gauge (12) is further provided with a support plate (1201), a terminal pressure measuring sleeve (1203), a second damping spring (1204), a bearing flange (1205) and a thrust bearing (1206), wherein: the terminal pressure sensor (1202) is fixed between the end plate of the terminal pressure measuring sleeve (1203) and the vertical plate of the support plate (1201) by means of bolts; the bottom plate of the terminal pressure measuring sleeve (1203) is fixed to the fixed foundation (18) by means of bolts, and a reinforcing plate is provided between the bottom plate and the vertical plate of the terminal pressure measuring sleeve (1203); the bearing flange (1205) and the thrust bearing (1206) are connected by means of bolts, and the other end of the tube body of the terminal pressure measuring sleeve (1203) sleeved with the second damping spring (1204) passes through the bearing flange (1205) and is installed in the thrust bearing (1206); and the thrust bearing (1206) is fixedly connected to the flexible drill rod (6).

7. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions according to claim 1 is characterized in that: The transparent sleeve (8) is made of acrylic material. The sealing end covers (7) installed at both ends of the transparent sleeve (8) are provided with an outer end cover (701), an outer sealing cover (702), a sealing ring (703), an inner sealing cover (704), a sealing member (705), a retaining ring (706) and a sealing bearing (707), wherein: the outer end cover (701) and the outer sealing cover (702) are both cylindrical bodies with a T-shaped longitudinal section. The outer outer circle of the lower part of the outer sealing cover (702) is provided with a sealing ring (703). The outer sealing cover (702) is sleeved on the outer outer wall of the lower part of the outer end cover (701) and is connected to the outer end cover (701) by bolts. The outer diameter of the outer sealing cover (702) is equal to the inner diameter of the end of the transparent sleeve (8). The outer sealing cover (702) and the sealing ring (703) are matched and equipped with more than one sealing ring (703), and the sealing between the outer sealing cover (702) and the transparent sleeve (8) is achieved through the outer sealing cover (702) and the sealing ring (703); two retaining ring assembly grooves are provided in the center hole of the outer sealing cover (702), and a sealing bearing (707) is installed in the center hole between the two retaining ring assembly grooves; the inner sealing cover (704) is a cylindrical body with a T-shaped longitudinal section, the lower cylindrical body is installed in the center hole of the outer end cover (701), and the upper outer circular step is stuck in the upper end surface of the outer end cover (701), and the aperture of the center hole of the inner sealing cover (704) is consistent with the outer diameter of the flexible drill rod (6); and more than one sealing member (705) is installed in the center hole of the inner sealing cover (704).

8. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 5 is characterized in that: The electromagnetic dynamic torque sensor (5) is fixed in a fixed bracket and fixedly connected to a fixed foundation (18) via the fixed bracket; the rotating shafts at both ends of the electromagnetic dynamic torque sensor (5) are respectively connected to the flexible drill rod (6) and the output shaft of the stepper motor (3) via a coupling (4).

9. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions as claimed in claim 1 is characterized in that: The eddy current displacement sensor (10) is fixed in an eddy current displacement sensor bracket (11); the top and both sides of the eddy current displacement sensor bracket (11) are provided with sensor fixing holes; the eddy current displacement sensor bracket (11) is connected to a fixed foundation (18) via bolts; according to the test requirements for the flexible drill rod (6), a magnetic conductive element is attached to the outside of the flexible drill rod (6) corresponding to the eddy current displacement sensor (10); and the eddy current displacement sensor (10) is clamped in the eddy current sensor bracket (11) via nuts on both sides of the sensor fixing hole.

10. The flexible drill pipe horizontal section drilling experimental device based on drilling fluid working conditions according to claim 1, characterized in that: The sleeve bracket (9) is provided with an upper sleeve bracket (901) and a lower sleeve bracket (902), wherein arc grooves are provided in the upper sleeve bracket (901) and the lower sleeve bracket (902), and the inner circle formed by the arc grooves in the upper sleeve bracket (901) and the lower sleeve bracket (902) after being butted together by bolts is consistent with the outer circle of the transparent sleeve (8); the lower sleeve bracket (902) is fixedly connected to a fixed foundation (18) by bolts.

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