An electric pulse-pdc cooperative rock breaking drilling experiment system and method

Abstract

The application discloses an electric pulse-PDC cooperative rock breaking drilling experiment system and method, and the experiment system structure comprises a random frame module, a drilling module, a circulation module, a power module and a control monitoring module. A direct current power supply and a pulse generator drive the electric pulse drill bit to continuously discharge, and a servo motor drives the PDC drill bit to continuously rotate, so that the rock is broken under the synergistic effect of mechanical interaction and high-voltage electric pulse. The application can realize the whole process of the electric pulse drill bit and the PDC drill bit cooperating to break the rock, thereby completing the experimental research on the influence of high-voltage electric pulse parameters, drilling pressure, rotating speed, electric pulse drill bit structure parameters, PDC drill bit structure parameters, liquid medium types and rock types on the electric pulse-PDC cooperative rock breaking drilling efficiency, and helping to promote the application of the electric pulse rock breaking technology in oil and gas drilling engineering.

Description

Technical Field

[0001] This invention relates to the field of drilling technology, specifically to an experimental system and method for rock breaking drilling using an electrical pulse-PDC (Power Pulse Controlled Controller) system. Background Technology

[0002] With the continuous advancement of global industrialization and the ever-increasing demands of daily life, shallow and easily exploitable oil, gas, and mineral resources are becoming increasingly depleted. The combination of geopolitical risks and the resulting increasing supply-demand imbalances have forced humanity to gradually shift its focus in developing Earth's resources to deeper depths, making drilling engineering increasingly challenging. With increasing depth, geological conditions become more complex and demanding, with rocks exhibiting significantly increased hardness, density, and abrasiveness, often accompanied by high temperatures and pressures. Traditional rotary drilling technology, when applied to deep formations, generally faces prominent challenges such as low mechanical drilling speeds and severe drill bit wear, requiring frequent tripping and bit replacements, significantly increasing the cost per meter of drilling footage and severely hindering the overall progress and large-scale advancement of resource development. Therefore, exploring more efficient new drilling technologies and their corresponding drill bits has become an important means to improve the efficiency of deep material and energy exploration and development. Piezoelectric pulse rock breaking technology has unique advantages such as high breaking efficiency, controllable energy, and no pollution, and its drilling costs are not limited by drilling depth, making it a technology with enormous engineering application potential. Therefore, in recent years, high-voltage electric pulse rock breaking technology has been extensively tested in the oil and gas drilling field, achieving some progress.

[0003] However, the structure of electric pulse drill bits is generally fragile, limiting their ability to withstand low drilling pressure and hindering directional drilling. Furthermore, the random discharge of electric pulse drill bits results in rough, unstable wellbores formed within the rock. To compensate for the shortcomings of electric pulse rock breaking technology in drilling engineering, some scholars and practitioners have proposed electric pulse-mechanical composite drill bit structures. However, research on the high-voltage electric pulse-mechanical composite rock breaking drilling process is currently limited to theoretical analysis and numerical simulation, lacking experimental data support, resulting in a technological gap at present. In addition, the high-voltage pulse power supply currently used with electric pulse-mechanical composite rock breaking drill bits is generally large and cannot be carried downhole with the composite drill bit, requiring surface installation. This leads to significant energy loss, preventing the achievement of efficient rock breaking. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an experimental system and method for electric pulse-PDC (electric pulse-PDC) collaborative rock-breaking drilling. By adopting a novel structural design, it can more accurately simulate the experimental environment of electric pulse drilling under real drilling conditions, providing more accurate test data to guide drilling production.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An experimental system for rock breaking drilling using an electrical pulse-PDC (Power Pulse Controlled Controller) system includes a frame module, a drilling module, a circulation module, a power module, and a control and monitoring module. The frame module includes a frame base with multiple supporting guide columns. A fixed top platform is mounted on the top of each guide column, and a lifting platform that can move up and down along the guide columns is fitted onto each guide column. The lifting platform is used to fix and move the drilling module. The power module provides power for the movement of the drilling module. The circulation module includes a liquid pool and a rock-breaking fluid cylinder. An inlet pipe and an outlet pipe are connected between the liquid pool and the rock-breaking fluid cylinder. The rock-breaking fluid cylinder is mounted on the frame base. Rock samples for the experiment can be installed inside the rock-breaking fluid cylinder. The frame base is fixed to the ground, and a rock chuck is mounted on top of it. The rock chuck is placed inside the rock-breaking fluid cylinder to clamp and fix the rock sample. A groove for installing a sealing strip is provided on the outer periphery of the bottom of the rock-breaking fluid cylinder to ensure the sealing of the cylinder.

[0007] Furthermore, the lifting platform has a through hole, and a mounting plate support column is installed on the upper surface of the lifting platform outside the through hole. The top of the mounting plate support column is fixedly connected to the sensor mounting plate. Two insulating fixing rods are provided on the lower surface of the outside of the through hole.

[0008] Furthermore, the drilling module includes a high-voltage pulse generator, an insulated handle above the high-voltage pulse generator, and a hollow drill string fitted on its lower outer side. The hollow drill string has a large through hole and a small through hole inside. The high-voltage pulse generator is placed in the large through hole. The bottom of the hollow drill string has an outwardly flared perforated edge, which is connected to a water inlet connector via drill string screws and drill string nuts. A PDC drill bit is connected below the water inlet connector via drill bit screws. Both the PDC drill bit and the water inlet connector are axially hollow structures, and the lower side of the PDC drill bit's inner cavity has an inwardly recessed section. A step is provided, through which an axially hollow drill bit insulating rod is fixed. An axially hollow insulating joint is provided above the drill bit insulating rod, and the top of the insulating joint is inserted into a small through hole. The top of the insulating joint abuts against the lower end of the high-voltage pulse generator. A metal conductive rod, an electrode connector, and a high-voltage electrode are provided from top to bottom in the insulating joint and the drill bit insulating rod. The metal conductive rod passes through the central through hole of the insulating joint, and its upper part is fixedly connected to the lower output end of the high-voltage pulse generator. An inward step is provided at the lower outer side of the drill bit insulating rod, and a grounding electrode is sleeved on the inward step.

[0009] Furthermore, the electrode connector has a cylindrical structure with a countersunk hole at the top and a threaded hole at the bottom; the lower end of the metal conductive rod is inserted into the countersunk hole a; the top of the high-voltage electrode has a high-voltage electrode thread, a high-voltage electrode shoulder is provided below the high-voltage electrode thread, and a high-voltage mounting cylindrical surface is below the high-voltage electrode shoulder; the high-voltage electrode thread mates with the threaded hole of the connector, and the high-voltage electrode shoulder is in close contact with the lower end face of the electrode connector;

[0010] Furthermore, a water ring is fitted around the outside of the water-passing connector. The water-passing connector passes through the water ring through hole in the center of the water ring. An internally tangential annular groove is provided in the middle section of the outer periphery of the water-passing connector. Two sets of water ring sealing rings are provided between the water ring and the water-passing connector. The two sets of water ring sealing rings fit together the internally tangential annular groove. A channel one is provided in the internally tangential annular groove, which passes through the wall of the water-passing connector and connects to the bottom of the water-passing connector. There is at least one channel one. A channel two is provided on the PDC drill bit corresponding to the bottom of the channel, which connects to the bottom of the PDC drill bit. A drill bit sealing ring that can seal the channel one and the channel two is provided between the PDC drill bit and the water-passing connector.

[0011] Furthermore, the sidewall of the water ring is provided with at least one water ring inlet. The outer side of the water ring inlet is connected to the inlet pipe, and the inner side of the water ring inlet passes through the wall of the water ring and connects to the position of the corresponding inscribed annular groove, thereby transporting the liquid in the liquid pool to the second channel of the PDC drill bit. Two outward-facing fixing plates are provided on the outer side of the water ring. The fixing plates are provided with water ring fixing holes. The insulating fixing rod is a long cylindrical structure with threads machined on the cylindrical surfaces at both ends. Its upper part is fixedly connected to the lower part of the lifting platform by threads, and its lower part passes through the water ring fixing hole. Fixing rings are installed on the upper and lower end faces of the water ring fixing hole. The fixing ring is a circular ring structure with threads machined on its inner circumference, and it is fixedly connected to the insulating fixing rod by threads.

[0012] Furthermore, the power module includes a balance cylinder group, a pressurization cylinder group, a pre-stage power supply, a pulse pressurization cylinder, and a servo motor;

[0013] The control and monitoring module includes a control cabinet, which is connected to a pulse displacement sensor, a feed displacement sensor, and a pressure sensor via a data cable.

[0014] A through hole is opened in the center of the fixed top platform, and cylinder mounting platforms are provided on both sides. The cylinder bodies of the balancing cylinder group and the pressurizing cylinder group are fixed to the upper surface of the cylinder mounting platforms by screws. Pressure sensors are provided on the push rod end faces of the balancing cylinder group and the pressurizing cylinder group. The pressure sensors are fixed to the upper surface of the lifting platform. The advance displacement sensor is installed between the upper surface of the lifting platform and the lower surface of the fixed top platform. The pre-stage power supply is fixed to the upper surface of the fixed top platform. A pulse displacement sensor and a pulse pressurizing cylinder are installed on the sensor mounting plate. The lower part of the pulse displacement sensor and the pulse pressurizing cylinder are fixed to the upper end face of the insulated handle by screws. The servo motor is fixed to the lifting platform. The lifting platform contains a reduction gear group, and the middle part is a hollow turntable. The top of the hollow drill string is fixed to the hollow turntable of the lifting platform by screws.

[0015] Furthermore, the liquid pool has a barrel structure and is mounted on a liquid pool trolley for mobility; a liquid pump is also installed on the liquid pool trolley; a waste water valve and a water outlet valve are provided below the liquid pool, and a water pumping pipe is also provided to connect to the water outlet valve and the liquid pump for water intake; the outlet of the liquid pump is equipped with a circulating water inlet valve and a return water valve, and the rock-breaking liquid cylinder is equipped with a circulating water outlet valve.

[0016] Furthermore, the spatial configuration of the high-voltage working head in contact with the rock is one of a single-headed conical rod, a claw-shaped multi-headed conical rod, or a concave thin plate; the spatial configuration of the grounding working head in contact with the rock is one of a multi-headed conical rod, a concave thin plate, a closed ring, or a multi-headed conical rod with an L-shaped bend; the spatial configuration of the lower end of the drill bit insulating rod is one of an externally convex truncated cone or an internally concave conical surface; the spatial configuration of the lower end of the drill bit insulating rod is one of an externally convex truncated cone, an internally concave conical surface, or a flat top surface.

[0017] An experimental method for rock breaking drilling using an electrical pulse-PDC synergistic system, employing the aforementioned electrical pulse-PDC synergistic rock breaking drilling experimental system, comprises the following specific steps:

[0018] Step S1: Fix the rock with the rock chuck, install the sealing strip in the sealing strip groove, fix the rock breaking liquid cylinder to the frame base with screws, and keep the waste water valve, outlet water valve, circulating water inlet valve, return water valve and circulating water outlet valve in the closed state.

[0019] Step S2: Connect the system power supply and control the pressurized cylinder assembly via the control cabinet to lower the lifting platform. When the PDC drill bit, high-pressure working head, and grounding working head are in close contact with the upper surface of the rock, stop the descent via the control cabinet.

[0020] Step S3: Open the outlet valve and the circulating inlet valve, and start the liquid pump. The drilling fluid enters the rock-breaking fluid cylinder through the path of liquid pool → pumping pipe → liquid pump → inlet pipe → water ring → PDC drill bit → rock-breaking fluid cylinder. When the drilling fluid surface completely submerges the PDC drill bit, close the outlet valve and the liquid pump, and open the circulating outlet valve.

[0021] Step S4: After setting the relevant parameters and experimental stop conditions in the control cabinet, start the liquid pump, pressurized cylinder group, servo motor and pre-stage power supply with one key in the control cabinet to start the rock breaking drilling experiment; real-time data of drilling pressure, torque and footage during the experiment are obtained through pulse displacement sensor, footage displacement sensor, pressure sensor and servo motor, and displayed in real time on the control touch screen of the control cabinet.

[0022] Step S5: Once the experiment stops, the entire system automatically stops; the experimental data is retrieved from the control cabinet using a mobile storage device.

[0023] Step S6: Control the pressurized cylinder group through the control cabinet to drive the lifting platform to rise, so that the PDC drill bit, high-pressure working head and grounding working head are separated from the rock and raised to a suitable height; close the circulating water inlet valve and open the return water valve, then start the liquid pump, and return the drilling fluid to the liquid pool through the path of rock breaking fluid cylinder → water outlet pipe → liquid pump → return water pipe → liquid pool;

[0024] Step S7: Separate the rock-breaking fluid cylinder from the frame base, remove the rock from the rock chuck, and clean up the rock debris;

[0025] Step S8: If you need to conduct the experiment again, repeat steps S1 to S7 until the experiment is finally completed.

[0026] The beneficial effects of this invention are:

[0027] 1. The experimental system provided by this invention has a higher degree of integration, reduces the size of the high-voltage pulse generator, and can realize the synchronous movement of the high-voltage pulse generator and the pulse-PDC drill bit, effectively reducing energy loss;

[0028] 2. It facilitates observation of the experimental process, and can measure the feed rate of the electric pulse drill bit and the PDC drill bit separately through the control detection module. The test results are fed back in real time without the need for manual measurement. It can be used for the matching study of electric pulse rock breaking parameters and PDC rock breaking parameters, thereby further improving energy utilization efficiency.

[0029] 3. The circulation module facilitates the replacement of liquid media, enabling the use of various liquid media as drilling fluid, easily meeting the needs of various testing environments, and achieving complete circulation of drilling fluid;

[0030] 4. It can be used to conduct experimental studies on the effects of high-voltage electric pulse parameters, drilling pressure, rotation speed, electric pulse drill bit structural parameters, PDC drill bit structural parameters, liquid medium type, and rock type on the efficiency of electric pulse-PDC synergistic rock breaking drilling. Attached Figure Description

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] Figure 1 This is a schematic diagram of the overall structure of the electrical pulse-PDC collaborative rock-breaking drilling experimental system;

[0033] Figure 2 A schematic diagram of part of the experimental system for rock breaking drilling using electrical pulse-PDC synergistic technology.

[0034] Figure 3 This is a schematic diagram of the rack module structure;

[0035] Figure 4 This is a schematic diagram of the drilling module structure;

[0036] Figure 5 for Figure 4 Detailed view of the lower side;

[0037] Figure 6 This is a schematic diagram of the loop module structure;

[0038] Figure 7 This is a schematic diagram of a hollow drill string structure;

[0039] Figure 8 This is a schematic diagram of the PDC drill bit structure;

[0040] Figure 9 This is a schematic diagram of the electrode connector structure;

[0041] Figure 10 This is a schematic diagram of the spatial configuration of the high-voltage electrode;

[0042] Figure 11 This is a schematic diagram of the spatial configuration of the grounding electrode;

[0043] Figure 12 This is a schematic diagram of the spatial configuration of the drill bit insulating rod.

[0044] In the picture:

[0045] 101. Fixed top platform; 102. Support guide column; 103. Lifting platform; 104. Frame base; 105. Mounting plate; 106. Mounting plate support column; 107. Insulating fixing rod; 108. Rock chuck; 109. Fixing ring; 110. Sealing strip groove;

[0046] 201. Insulated handle; 202. High-voltage pulse generator; 203. Hollow drill string; 203a. Large through hole; 203b. Small through hole; 204. Drill string screw; 205. Drill string nut; 206. Water connector; 206a. Internal annular groove; 206b. Channel one; 207. Drill bit screw; 208. PDC drill bit; 208a. Sealing ring groove; 208b. Drill bit through hole; 208c. Screw mounting hole; 208d. Channel two; 208e. Cylindrical step; 209. Insulated connector; 210. Metal conductive rod; 211. Drill bit sealing ring; 212. High-voltage electrode; 212a. Conductive countersunk hole; 212b. Limiting step; 212c. High-voltage mounting cylindrical surface; 212d. High-voltage working head; 213. Drill bit insulating rod; 213a. Large countersunk hole; 213b. Small countersunk hole; 213c. Insulator step; 213d. Insulator rod through hole; 213e. Insulator step; 213f. Sliding cylindrical surface; 213g. Mounting cylindrical surface; 214. Grounding electrode; 214a. Mounting ring; 215. Electrode connector;

[0047] 301. Liquid pool; 302. Liquid pump; 302a. Circulating water inlet valve; 302b. Return water valve; 303. Pumping pipe; 304. Inlet pipe; 305. Water ring; 305a. Water ring inlet; 305b. Water ring fixing hole; 305c. Water ring through hole; 306. Rock-breaking liquid cylinder; 307. Outlet pipe; 308. Return water pipe; 309. Liquid pool trolley; 310. Water ring sealing ring;

[0048] 401. Balanced cylinder assembly; 402. Pressurized cylinder assembly; 403. Pre-amplifier power supply; 404. Pulse pressurization cylinder; 405. Servo motor;

[0049] 501. Control cabinet; 502. Pulse displacement sensor; 503. Footprint displacement sensor; 504. Pressure sensor. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments. It should be noted that, in this document, terms such as "upper" and "lower" are used merely for convenience in describing the accompanying drawings and are not intended to limit the direction in actual use, nor do they necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0051] like Figure 1-9As shown, an electrical pulse-PDC collaborative rock-breaking drilling experimental system includes a frame module 1, a drilling module 2, a circulation module 3, a power module 4, a control and monitoring module 5, and a rock sample 6 for use as the experimental object. In a preferred embodiment, the frame module 1 includes a fixed top platform 101, a support guide column 102, a lifting platform 103, a frame base 104, a mounting plate 105, a mounting plate support column 106, an insulating fixing rod 107, a rock chuck 108, a fixing ring 109, and a sealing groove 110; the drilling module 2 includes an insulating handle 201, a high-voltage pulse generator 202, a hollow drill string 203, a drill string screw 204, a drill string nut 205, a water connector 206, a drill bit screw 207, a PDC drill bit 208, an insulating connector 209, a metal conductive rod 210, a drill bit sealing ring 211, a high-voltage electrode 212, a drill bit insulating rod 213, a grounding electrode 214, and an electrode... Connector 215; The circulation module 3 includes a liquid pool 301, a liquid pump 302, a pumping pipe 303, an inlet pipe 304, a water ring 305, a rock-breaking liquid cylinder 306, an outlet pipe 307, a return pipe 308, a liquid pool trolley 309, and a water ring sealing ring 310; The power module 4 includes a balance cylinder group 401, a pressurizing cylinder group 402, a pre-stage power supply 403, a pulse pressurizing cylinder 404, and a servo motor 405; The control and monitoring module 5 includes a control cabinet 501, a pulse displacement sensor 502, a feed displacement sensor 503, and a pressure sensor 504; The frame base 104 is fixed to the ground, and its upper end face has an opening for connecting the rock chuck 108 to the frame base 10. 4. A threaded hole for fixing the rock-breaking fluid cylinder 306 to the frame base 104; the sealing strip groove 110 is disposed on the upper end face of the frame base 104, located between the rock chuck 108 and the threaded hole for fixing the rock-breaking fluid cylinder 306 to the frame base 104; the sealing strip groove 110 is used to install a sealing strip to prevent drilling fluid for testing from seeping out of the rock-breaking fluid cylinder 306 and the frame base 104; the lifting platform 103 has a through hole, and the support guide column 102 passes through the through hole of the lifting platform 103; the central axis of the support guide column 102 is perpendicular to the horizontal plane, and its lower end is fixed to the frame base 104 by threads; the lifting platform 103 The upper surface is equipped with a mounting plate support column 106, the top of which is fixedly connected to the sensor mounting plate 105. A pulse displacement sensor 502 and a pulse pressurization cylinder 404 are mounted on the sensor mounting plate 105. The lower parts of the pulse displacement sensor 502 and the pulse pressurization cylinder 404 are fixedly connected to the upper end face of the insulated handle 201 by screws. The servo motor 405 is fixedly connected to the lifting platform 103. The lifting platform 103 contains a reduction gear set, with a hollow turntable in its middle. The top of the hollow drill column 203 is fixedly connected to the hollow turntable of the lifting platform 103 by screws. The hollow drill column 203 has a large through hole 203a and a small through hole 203b inside.The high-voltage pulse generator 202 is placed in the large through hole 203a; the insulating handle 201 is fixedly connected to the top end face of the high-voltage pulse generator 202; the insulating connector 209 has a central through hole, and its lower outer circumferential surface has threads, and its upper end face is fixedly connected to the lower end face of the high-voltage pulse generator 202, and the insulating connector 209 is placed in 203b; the metal conductive rod 210 passes through the central through hole of the insulating connector 209, and its upper part is fixedly connected to the lower output end of the high-voltage pulse generator 202; the electrode connector 215 has a cylindrical structure. The upper part has a countersunk hole 215a for the connector, and the lower part has a threaded hole 215b for the connector. The lower end of the metal conductive rod 210 is inserted into the countersunk hole 215a for the connector. The top of the high-voltage electrode 212 has a high-voltage electrode thread 212a, and a high-voltage electrode shoulder 212b is provided below the high-voltage electrode thread 212a. Below the high-voltage electrode shoulder 212b is a high-voltage mounting cylindrical surface 212c. The high-voltage electrode thread 212a mates with the threaded hole 215b for the connector, and the high-voltage electrode shoulder 212b is in close contact with the lower end face of the electrode connector 215. The grounding electrode 214 is fixed and installed using a ring-shaped mounting ring 214a, the upper end face of which is fixed to the grounding electrode shoulder 213e, and its inner cylindrical surface mates with the mounting cylindrical surface 213g; the PDC drill bit 208 has a sealing ring groove 208a on its top end face, a drill bit through hole 208b in the center, a cylindrical step 208e on the upper center, and screw mounting holes 208c on the upper outer circumference; the PDC drill bit 208 has... The drill bit has a channel 208d; the sliding cylindrical surface 213f and the grounding electrode 214 pass through the drill bit through hole 208b; the insulator step 213c mates with the cylindrical step 208e; the drill bit sealing ring 211 is installed in the sealing ring groove 208a; the water ring 305 has a water ring through hole 305c in the center; the water connector 206 passes through the water ring through hole 305c; the upper part of the water connector 206 is connected to the lower part of the hollow drill string 203 by a drill string screw. 204 is fixedly connected to the drill string nut 205, and the lower part of the water connector 206 is fixedly connected to the upper part of the PDC drill bit 208 by the drill bit screw 207; a water ring sealing ring 310 is installed between the water ring 305 and the water connector 206; an inner circumferential groove 206a is provided in the middle section of the outer periphery of the water connector 205, and multiple water ring sealing rings 310 are provided on the upper and lower sides of the inner circumferential groove 206a; a channel 206b is provided in the inner circumferential groove, passing through the wall of the water connector 205 and connecting to the bottom of the water connector 205, and the number of channels 206b is at least one. In this embodiment, it is preferred to have two. Therefore, a channel 208d is provided on the PDC drill bit 208 corresponding to the bottom of the channel and connected to the bottom of the PDC drill bit 208. A drill bit sealing ring 211 that can seal channels 206b and 208d is provided between the PDC drill bit 208 and the water connector 206.The insulating fixing rod 107 is a long cylindrical structure with threads machined on its upper and lower cylindrical surfaces. Its upper part is threadedly connected to the lower part of the lifting platform 103, and its lower part passes through a water ring fixing hole 305b. Fixing rings 109 are installed on the upper and lower end faces of the water ring fixing hole 305b. The fixing ring 109 is a circular ring structure with threads machined on its inner circumference, and is threadedly connected to the insulating fixing rod 107. The top of the supporting guide column 102 is fixedly connected to the fixed top platform 101. The fixed top platform 101 has a top platform through hole 101a in its center, and cylinder mounting platforms 101b on both sides. The cylinder bodies of the balancing cylinder assembly 401 and the pressurizing cylinder assembly 402 are fixedly connected to the upper surface of the cylinder mounting platform 101b by screws; the push rod end faces of the balancing cylinder assembly 401 and the pressurizing cylinder assembly 402 are fixedly connected to the pressure sensor 504; the pressure sensor 504 is fixedly connected to the upper surface of the lifting platform 103; the advance displacement sensor 503 is installed between the upper surface of the lifting platform 103 and the lower surface of the fixed top platform 101; the pre-stage power supply 403 is fixedly connected to the upper end face of the fixed top platform 101; the liquid tank trolley 309 is a movable handcart, and the liquid tank 301 and the liquid pump 30... 2. The liquid tank trolley 309 is fixedly connected to the liquid tank 301; the lower part of the liquid tank 301 is provided with a waste water valve 301a and a water outlet valve 301b; the water pump 303 is fixedly connected to the water outlet valve 301b and the water inlet of the liquid pump 302; the water outlet of the liquid pump 302 is provided with a circulating water inlet valve 302a and a return water valve 302b; the lower end face of the rock-breaking liquid cylinder 306 has a through hole, and a screw passes through the through hole and engages with the threaded hole on the upper end face of the frame base 104 for fixing the rock-breaking liquid cylinder 306 to the frame base 104, thereby fixing the rock-breaking liquid cylinder 306 to the frame base 104; The rock-breaking liquid cylinder 306 is equipped with a circulating water outlet valve 306a; the water inlet pipe 304 is fixedly connected to the circulating water inlet valve 302a and the water ring inlet 305a; the water outlet pipe 307 is fixedly connected to the water inlet of the liquid pump 302 and the circulating valve 306a; the liquid pool 301 has a through hole at the top, and the return water pipe 308 is fixedly connected to the through hole and the return water valve 302b; the control cabinet 501 has a control touch screen, status indicator lights, and an emergency stop button. The control touch screen can display the changes in drilling pressure, torque, and drilling depth curves in real time during the experiment; the control cabinet 501 has data reading and writing functions.

[0052] like Figure 12The drill bit insulating rod 213 has a large countersunk hole 213a on its upper part, and a thread on the inner cylindrical surface of 213a. A small countersunk hole 213b is formed below the large countersunk hole 213a. The drill bit insulating rod 213 has an insulating rod through hole 213d in its center. The insulating connector 209 is fixedly connected to the drill bit insulating rod 213 through the thread on the lower outer circumferential surface of the insulating connector 209 and the thread on the inner cylindrical surface of 213a. The upper part of the drill bit insulating rod 213 is an insulating step 213c, the middle and lower part of the drill bit insulating rod 213 is a grounding electrode shoulder 213e, and the lower part is a mounting cylindrical surface 213g; the sliding cylindrical surface 213f is between the insulating step 213c and the grounding electrode shoulder 213e; the high voltage electrode 212 is installed inside the drill bit insulating rod 213, and the high voltage mounting cylindrical surface 212c cooperates with the insulating rod through hole 213d, the limiting step 212b cooperates with the small countersunk hole 213b.

[0053] The high-voltage pulse generator 202 and the hollow drill string 203, the hollow drill string 203 and the insulating joint 209, the insulating joint 209 and the water-passing joint 206, the PDC drill bit 208 and the drill bit insulating rod 213, and the water-passing joint 206 and the cylindrical surface of the water ring 305 are all clearance fits.

[0054] The number of channels 208d inside the PDC drill bit 208 can preferably be twice the number of the PDC drill bit 208 blades. The channels 208d are distributed on the cylindrical surface where the blade notches of the PDC drill bit 208 intersect with the blade ends and the drill bit through hole 208b.

[0055] The inner diameter of the drill bit through hole 208b inside the PDC drill bit 208 is the same as the outer diameter of the sliding cylindrical surface 213f and the outer cylindrical surface of the grounding electrode 214; the number of screw mounting holes 208c is 6 to 8.

[0056] The high-voltage electrode 212, in contact with the rock, has a spatial configuration of either a single-ended conical rod, a claw-shaped multi-ended conical rod, or a concave thin plate, suitable for soft / medium-hard, hard, and extremely hard formations, respectively. The grounding electrode 214, in contact with the rock, has a spatial configuration of either a multi-ended conical rod, a concave thin plate, a closed ring, or a "multi-ended conical rod with an L-shaped bend," suitable for hard, extremely hard, medium-hard, and soft formations, respectively. The lower end of the drill bit insulating rod has a spatial configuration of either a convex frustum or a concave conical surface. The specific choice depends on the spatial configuration of the high-voltage working head 212d. For example, the lower end of the drill bit insulating rod 213 has a spatial configuration of either a convex frustum, a concave conical surface, or a flat top surface, suitable for soft / medium-hard, extremely hard, and hard formations, respectively. Therefore, more formation rock samples 6 can be tested, meeting a wider range of experimental needs.

[0057] The mounting plate 105, insulating fixing rod 107, insulating handle 201, hollow drill column 203, insulating joint 209, drill bit insulating rod 213, liquid pool 301, water pumping pipe 303, water inlet pipe 304, rock breaking liquid cylinder 306, water outlet pipe 307, and return water pipe 308 are all made of insulating material.

[0058] The drilling fluid used in the experimental system is one of the following: distilled water, deionized water, oil-based mud, water-based mud, tap water, transformer oil, or hydraulic oil. Because the liquid tank 301 is easy to move and allows for easy access to and removal of the liquid, the process of changing the drilling fluid is very convenient and can meet different experimental needs.

[0059] The experimental method using the above-mentioned electrical pulse-PDC synergistic rock-breaking drilling experimental system includes the following specific steps:

[0060] Step S1: Fix the rock 6 with the rock chuck 108, install the sealing strip in the sealing strip groove 110, fix the rock breaking liquid cylinder 306 to the frame base 104 with screws, and keep the waste water valve 301a, water outlet valve 301b, circulating water inlet valve 302a, return water valve 302b, and circulating water outlet valve 306a in the closed state.

[0061] Step S2: Connect the system power supply and control the pressurized cylinder group 402 to drive the lifting platform 103 to descend via the control cabinet 501. When the PDC drill bit 208, high-pressure working head 212d, and grounding working head 214b are in close contact with the upper surface of the rock 6, control the descent to stop via the control cabinet 501.

[0062] Step S3: Open the outlet valve 301b and the circulating inlet valve 302a, and start the liquid pump 302. The drilling fluid enters the rock-breaking fluid cylinder 306 through the path of liquid pool 301 → pumping pipe 303 → liquid pump 302 → inlet pipe 304 → water ring 305 → PDC drill bit 208 → rock-breaking fluid cylinder 306. When the drilling fluid surface completely submerges the PDC drill bit 208, close the outlet valve 301b and the liquid pump 302, and open the circulating outlet valve 306a.

[0063] Step S4: After setting the relevant parameters and experimental stop conditions in the control cabinet 501, start the liquid pump 302, pressurized cylinder group 402, servo motor 405 and pre-stage power supply 403 with one key in the control cabinet 501 to start the rock breaking drilling experiment; real-time data of drilling pressure, torque and footage during the experiment are obtained through pulse displacement sensor 502, footage displacement sensor 503, pressure sensor 504 and servo motor 405 and displayed in real time on the control touch screen of the control cabinet 501;

[0064] Step S5: When the experiment stops, the entire system automatically stops; the experimental data is retrieved from control cabinet 5 via a mobile storage device.

[0065] Step S6: Control the pressurized cylinder group 402 through the control cabinet 501 to drive the lifting platform 103 to rise, so that the PDC drill bit 208, high-pressure working head 212d and grounding working head 214b are separated from the rock 6 and raised to a suitable height; close the circulating water inlet valve 302a and open the return water valve 302b, then start the liquid pump 302, and return the drilling fluid to the liquid pool 301 through the path of rock breaking fluid cylinder 306 → water outlet pipe 307 → liquid pump 302 → return water pipe 308 → liquid pool 301;

[0066] Step S7: Separate the rock-breaking liquid cylinder 306 from the frame base 104, remove the rock from the rock chuck 108, and clean up the rock debris;

[0067] Step S8: If you need to continue the experiment, repeat steps S1 to S7 until the experiment is over.

[0068] In step S4, the feed rate of the PDC drill bit is obtained through the feed rate displacement sensor 503, and the relative movement distance between the electric pulse drill bit and the PDC drill bit is obtained through the pulse displacement sensor 502. The feed rate of the electric pulse drill bit can be obtained from the feed rate of the PDC drill bit and the relative movement distance. This test allows for real-time acquisition of the relative displacement between the electric pulse drill bit and the PDC drill bit. If the relative displacement exceeds a limit during drilling, it can be adjusted back to within the limit by adjusting the discharge parameters (frequency, voltage) and the operating parameters of the PDC drill bit (rotation speed, drilling pressure). Simultaneously, the feed rate data can be used to discuss the matching of drilling parameters between the two drill bits to obtain the optimal parameter combination for a specific drill bit structure.

[0069] The above description is not intended to limit the present invention in any way. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method, characterized in that, The system includes a frame module (1), a drilling module (2), a circulation module (3), a power module (4), and a control and monitoring module (5). The frame module (1) includes a frame base (104), on which multiple support guide columns (102) are provided. A fixed top platform (101) is provided on the top of the support guide columns (102), and a lifting platform (103) that can move up and down along the support guide columns (102) is fitted on the support guide columns (102). The lifting platform (103) is used to fix and move the drilling module (2). The power module (4) is used to provide power for the movement of the drilling module (2). The circulation module (3) includes a liquid pool (3). 01) A water inlet pipe (304) and a water outlet pipe (307) are provided between the rock-breaking liquid cylinder (306), the liquid pool (301) and the rock-breaking liquid cylinder (306). The rock-breaking liquid cylinder (306) is installed on the frame base (104). A rock sample (6) for experimentation can be installed in the rock-breaking liquid cylinder (306). The frame base (104) is fixed on the ground and a rock chuck (108) is installed on top. The rock chuck (108) is set in the rock-breaking liquid cylinder (306) to clamp and fix the rock sample (6). A sealing strip groove (110) is provided on the bottom outer periphery of the rock-breaking liquid cylinder (306) for installing a sealing strip to ensure the sealing of the rock-breaking liquid cylinder (306).

2. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 1, characterized in that, The lifting platform (103) has a through hole, and a mounting plate support column (106) is installed on the upper surface outside the through hole. The top of the mounting plate support column (106) is fixedly connected to the sensor mounting plate (105). Two insulating fixing rods (107) are provided on the lower surface outside the through hole.

3. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 2, characterized in that, The drilling module (2) includes a high-pressure pulse generator (202), an insulated handle (201) above the high-pressure pulse generator (202), and a hollow drill string (203) sleeved on the lower outer side. The hollow drill string (203) has a large through hole (203a) and a small through hole (203b) inside. The high-pressure pulse generator (202) is placed in the large through hole (203a). The bottom of the hollow drill string (203) has an outwardly flared perforated edge. The perforated edge is connected to a water inlet connector (206) through a drill string screw (204) and a drill string nut (205). A PDC drill bit (208) is connected below the water inlet connector (206) through a drill bit screw (207). Both the PDC drill bit (208) and the water inlet connector (206) are axially hollow structures, and the inner cavity of the PDC drill bit (208) is... A recessed step is provided on the side, through which an axially hollow drill bit insulating rod (213) is fixed; an axially hollow insulating joint (209) is provided above the drill bit insulating rod (213), the top of the insulating joint (209) is inserted into a small through hole (203b), and the top of the insulating joint abuts against the lower end of the high voltage pulse generator (202). A metal conductive rod (210), an electrode joint (215), and a high voltage electrode (212) are provided from top to bottom in the insulating joint (209) and the drill bit insulating rod (213); the metal conductive rod (210) passes through the central through hole of the insulating joint (209), and its upper part is fixedly connected to the lower output end of the high voltage pulse generator (202); a recessed step is provided on the lower outer side of the drill bit insulating rod (213), and a grounding electrode (214) is sleeved on the recessed section.

4. The electrical pulse-PDC synergistic rock-breaking drilling experimental system according to claim 3, characterized in that, The electrode connector (215) has a cylindrical structure with a countersunk hole (215a) at the top and a threaded hole (215b) at the bottom. The lower end of the metal conductive rod (210) is inserted into the countersunk hole (215a). The top of the high-voltage electrode (212) is a high-voltage electrode thread (212a), and a high-voltage electrode shoulder (212b) is provided below the high-voltage electrode thread (212a). Below the high-voltage electrode shoulder (212b) is a high-voltage mounting cylindrical surface (212c). The high-voltage electrode thread (212a) mates with the threaded hole (215b), and the high-voltage electrode shoulder (212b) is in close contact with the lower end face of the electrode connector (215).

5. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 4, characterized in that, A water ring (305) is fitted around the outside of the water connector (206). The water connector (206) passes through the water ring through hole (305c) in the center of the water ring (305). An incised annular groove (206a) is provided in the middle section of the outer periphery of the water connector (206). Two sets of water ring sealing rings (310) are provided between the water ring (305) and the water connector (206). The two sets of water ring sealing rings (310) fit together the incised annular groove (206a). A water ring is provided in the incised annular groove. A channel 1 (206b) passes through the wall of the water inlet connector (205) and connects to the bottom of the water inlet connector (205). There is at least one channel 1 (206b). A channel 2 (206c) is provided on the PDC drill bit (208) corresponding to the bottom of the channel and connects to the bottom of the PDC drill bit (208). A drill bit sealing ring (211) that can seal the channel 1 (206b) and the channel 2 (206c) is provided between the PDC drill bit (208) and the water inlet connector (206).

6. The experimental system for rock breaking drilling with electrical pulse-PDC synergy according to claim 5, characterized in that, The side wall of the water ring (305) is provided with at least one water ring inlet (305a). The outer side of the water ring inlet (305a) is connected to the inlet pipe (304). The inner side of the water ring inlet (305a) passes through the wall of the water ring (305) and connects to the position of the corresponding internal annular groove (206a), thereby transporting the liquid in the liquid pool (301) to the second channel (206c) of the PDC drill bit (208). Two outward-facing fixing plates are provided on the outer side of the water ring (305). The fixing plate is provided with a water ring fixing hole (305b). The insulating fixing rod (107) is a long cylindrical structure with threads processed on the cylindrical surfaces at both ends. Its upper part is fixedly connected to the lower part of the lifting platform (103) by threads, and its lower part passes through the water ring fixing hole (305b). Fixing rings (109) are installed on the upper and lower end faces of the water ring fixing hole (305b). The fixing ring (109) is a circular ring structure with threads processed on its inner circumference surface. It is fixedly connected to the insulating fixing rod (107) by threads.

7. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 1, characterized in that, The power module (4) includes a balance cylinder group (401), a pressurization cylinder group (402), a pre-stage power supply (403), a pulse pressurization cylinder (404), and a servo motor (405). The control and monitoring module (5) includes a control cabinet (501), which is connected to a pulse displacement sensor (502), a feed displacement sensor (503), and a pressure sensor (504) via a data cable. The fixed top platform (101) has a top platform through hole (101a) in the center and cylinder mounting platforms (101b) on both sides; the cylinder bodies of the balancing cylinder group (401) and the pressurizing cylinder group (402) are fixed on the upper surface of the cylinder mounting platform (101b) by screws; pressure sensors (504) are provided on the push rod end faces of the balancing cylinder group (401) and the pressurizing cylinder group (402); the pressure sensors (504) are fixed to the upper surface of the lifting platform (103); the advance displacement sensor (503) is installed between the upper surface of the lifting platform (103) and the lower surface of the fixed top platform (101); The pre-amplifier (403) is fixedly connected to the upper end face of the fixed top platform (101); the sensor mounting plate (105) is equipped with a pulse displacement sensor (502) and a pulse pressurization cylinder (404), the lower part of the pulse displacement sensor (502) and the pulse pressurization cylinder (404) is fixedly connected to the upper end face of the insulated handle (201) by screws; the servo motor (405) is fixedly connected to the lifting platform (103); the lifting platform (103) contains a reduction gear set inside, the middle part of which is a hollow turntable, and the top of the hollow drill string (203) is fixedly connected to the hollow turntable of the lifting platform (103) by screws.

8. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 1, characterized in that, The liquid pool (301) has a barrel structure and is mounted on a liquid pool cart (309) to achieve a movable state. A liquid pump (302) is also provided on the liquid pool cart (309). A waste water valve (301a) and a water outlet valve (301b) are provided below the liquid pool. A water pumping pipe (303) is also provided to connect with the water outlet valve (301b) and the liquid pump (302) for water intake. The outlet of the liquid pump (302) is provided with a circulating water inlet valve (302a) and a return water valve (302b). The rock-breaking liquid cylinder (306) is provided with a circulating water outlet valve (306a).

9. The experimental system for rock breaking drilling using an electrical pulse-PDC synergistic method according to claim 1, characterized in that, The high-voltage electrode (212) in contact with the rock has a spatial configuration of a single-headed conical rod, a claw-shaped multi-headed conical rod, or a concave thin plate; the grounding electrode (214) in contact with the rock has a spatial configuration of a multi-headed conical rod, a concave thin plate, a closed ring, or a multi-headed conical rod with an L-shaped bend; the lower end of the drill bit insulating rod has a spatial configuration of a convex truncated cone or a concave conical surface; the lower end of the drill bit insulating rod (213) has a spatial configuration of a convex truncated cone, a concave conical surface, or a flat top surface.

10. An experimental method for rock-breaking drilling using a combination of electrical pulse and digital pulse control (PDC), characterized in that, The specific steps of the electrical pulse-PDC synergistic rock-breaking drilling experimental system as described in claims 1-9 are as follows: Step S1: Fix the rock (6) with the rock chuck (108), install the sealing strip in the sealing strip groove (110), fix the rock breaking liquid cylinder (306) to the frame base (104) with screws, and keep the waste water valve (301a), water outlet valve (301b), circulating water inlet valve (302a), return water valve (302b), and circulating water outlet valve (306a) in the closed state; Step S2: Connect the system power supply and control the pressurized cylinder group (402) through the control cabinet (501) to drive the lifting platform (103) to descend. When the PDC drill bit (208), high-pressure working head (212d), and grounding working head (214b) are in close contact with the upper surface of the rock (6), control the descent to stop through the control cabinet (501); Step S3: Open the outlet valve (301b) and the circulating inlet valve (302a), and start the liquid pump (302). The drilling fluid enters the rock-breaking fluid cylinder (306) through the path of liquid pool (301) → pump pipe (303) → liquid pump (302) → inlet pipe (304) → water ring (305) → PDC drill bit (208) → rock-breaking fluid cylinder (306). When the drilling fluid surface completely submerges the PDC drill bit (208), close the outlet valve (301b) and the liquid pump (302), and open the circulating outlet valve (306a). Step S4: After setting the relevant parameters and experimental stop conditions in the control cabinet (501), start the liquid pump (302), pressurized cylinder group (402), servo motor (405) and pre-stage power supply (403) with one key in the control cabinet (501) to start the rock breaking drilling experiment; obtain the real-time data of drilling pressure, torque and footage during the experiment through the pulse displacement sensor (502), footage displacement sensor (503), pressure sensor (504) and servo motor (405), and display them in real time on the control touch screen of the control cabinet (501); Step S5: When the experimental stopping condition is met, the entire system will automatically stop; the experimental data will be extracted from the control cabinet (5) using a mobile storage device; Step S6: Control the pressurized cylinder group (402) through the control cabinet (501) to drive the lifting platform (103) to rise, so that the PDC drill bit (208), high pressure working head (212d) and grounding working head (214b) are separated from the rock (6) and lifted to a suitable height; close the circulating water inlet valve (302a) and open the return water valve (302b), and then start the liquid pump (302) to return the drilling fluid to the liquid pool (301) through the path of rock breaking liquid cylinder (306) → water outlet pipe (307) → liquid pump (302) → return water pipe (308) → liquid pool (301); Step S7: Separate the rock-breaking liquid cylinder (306) from the frame base (104), remove the rock from the rock chuck (108), and clean up the rock debris; Step S8: If you need to conduct the experiment again, repeat steps S1 to S7 until the experiment is finally completed.

Images