Full-face drilling environment simulation experimental equipment and methods for raise boring machines

Abstract

This invention provides a full-section drilling environment simulation experimental device for a raise boring machine, comprising: a base, simulated rock blocks, a high-pressure sealing seat, and an experimental drilling rig; wherein, the bottom of the base is fixed to the ground; the simulated rock blocks are placed inside the base; the bottom of the high-pressure sealing seat is sealed and connected to the top of the base, and the top of the high-pressure sealing seat is mechanically and sealed to the experimental drilling rig, forming a high-pressure chamber inside the high-pressure sealing seat; this invention also provides a full-section drilling environment simulation experimental method for a raise boring machine, comprising the following steps: S1, extracting rock hardness data from the actual drilling location; S2, creating simulated rock blocks; S3, setting drilling parameters for the experimental drilling rig; S4, completing each drilling operation sequentially; S5, obtaining the optimal drilling speed V that best matches the actual drilling conditions. o Optimal hob wear δ o And the corresponding optimal thrust f o and optimal rotational torque T o And the critical drilling depth H for wellbore maintenance o .

Description

Technical Field

[0001] This invention relates to the field of reverse drilling rig drilling simulation technology, and in particular to a full-section drilling environment simulation experimental device and experimental method for reverse drilling rigs. Background Technology

[0002] In recent years, with the development of national industrial technology and the increase in energy demand, various engineering projects and mining construction require a large number of wellbore constructions. Due to the complex geological conditions in the construction areas, the technical difficulty of wellbore construction has increased, and the performance requirements for drilling equipment have also greatly improved. Among existing technologies, raise boring machines (RBMs) are one of the mainstream drilling equipment for wellbore construction. During construction, it is necessary to determine the construction parameters based on the rock hardness, wellbore parameters, and the condition of the cutting tools. Due to the lack of relevant simulation equipment, it is impossible to predict the construction parameters and wellbore conditions in advance, requiring analysis and construction to proceed simultaneously. Especially during construction, the pressure of the well-washing fluid increases with drilling depth, affecting the wellbore. When the wellbore is damaged by the well-washing fluid pressure and requires maintenance, the inability to predict this necessitates simultaneous analysis and maintenance during construction, severely impacting the efficiency of wellbore construction. Summary of the Invention

[0003] In view of this, it is necessary to provide a full-section drilling environment simulation experimental device and method for reverse drilling rigs that can simulate the drilling conditions of reverse drilling rigs.

[0004] According to one aspect of the present invention, a full-section drilling environment simulation experimental device for a raise boring machine is provided, comprising: a base, a simulated rock block, a high-pressure sealing seat, and an experimental drilling machine;

[0005] The base is cylindrical and its bottom is fixed to the ground. Simulated rock blocks are placed inside the base (the shape of the simulated rock blocks matches the inner cavity of the base, see instruction manual). The high-pressure sealing seat is bottomless and hollow. The bottom of the high-pressure sealing seat is connected to the top of the base by a flange seal. The top of the high-pressure sealing seat is equipped with a top cover, which is connected to the experimental drill motor seal. A high-pressure cavity is formed inside the high-pressure sealing seat.

[0006] The experimental drilling rig includes: drill frame, drilling rig main unit, control center, hydraulic control mechanism, well washing fluid supply mechanism, slag receiving mechanism, and monitoring mechanism;

[0007] The drill frame bottom is fixedly connected to the top cover of the high-pressure sealing seat; the main body of the drilling rig includes: a thrust cylinder, a power head housing, a power head, a power head spindle, drill rods, and drill bits;

[0008] The power head housing and drill frame are slidably connected vertically (with slide rails, as described in the instruction manual); the power head is fixed in the center of the power head housing; the cylinders of the thrust cylinders are symmetrically fixed around the perimeter of the power head housing, and the piston rods of the thrust cylinders are symmetrically fixed around the bottom perimeter of the drill frame. The thrust cylinders drive the power head housing and power head to slide vertically along the drill frame; the power head spindle is located inside the power head, and the inside of the power head spindle is hollow; the drill rod is fitted onto the power head spindle; the power head spindle rotates and moves axially under the drive of the power head, simultaneously driving the drill rod to rotate and move axially; the drill rod includes: a middle layer drill rod and an inner layer drill rod; the upper end of the middle layer drill rod is connected to the power head spindle, and the lower end of the middle layer drill rod is connected to the drill bit, used to transmit drilling pressure and rotational torque; the inner layer drill rod is fitted onto the power head spindle and the middle layer drill rod. Inside the drill rod, there is a gap between the outer wall of the inner drill rod and the inner wall of the power head spindle and the middle drill rod, forming a fluid inlet channel. The upper end of the fluid inlet channel is equipped with a well-washing fluid inlet, and the lower end of the well-washing fluid channel is connected to the drill bit. The well-washing fluid inlet is connected to the well-washing fluid supply mechanism through a pipeline, and the high-pressure well-washing fluid is sent to the drill bit. The drill bit is equipped with a well-washing fluid outlet. The inner drill rod is hollow inside, forming a return fluid channel. The upper part of the inner drill rod is fixedly connected to the power head housing, and the lower end of the inner drill rod penetrates the drill bit and extends into the high-pressure chamber, becoming the slag discharge inlet after the high-pressure well-washing fluid washes the well wall. The upper end of the inner drill rod is equipped with a slag discharge outlet, which is connected to the inlet of the slag receiving mechanism through a pipeline, and the high-pressure well-washing fluid after washing the well wall is sent to the slag receiving mechanism.

[0009] The monitoring mechanism includes: a first strain gauge pressure sensor, a second strain gauge pressure sensor, a displacement sensor, a rotary encoder, and several pressure sensors; the first strain gauge pressure sensor is installed on the connection surface between the drill pipe and the drill bit connection seat to measure the drilling pressure and monitor the thrust of the thrust cylinder; the second strain gauge pressure sensor is installed on the outer circumference of the drill pipe and drill bit connection seat to measure the rotational torque; the displacement sensor is installed on the thrust cylinder to measure the drilling speed; the rotary encoder is installed on the power head to measure the rotational speed provided by the power head to obtain the drill bit rotational speed; several pressure sensors are evenly distributed around the circumference of the experimental borehole within the simulated rock block to measure the wellbore bearing pressure data;

[0010] The control center is connected to the hydraulic control mechanism, the well-washing fluid supply mechanism, the first strain gauge pressure sensor, the second strain gauge pressure sensor, the displacement sensor, the rotary encoder, and several pressure sensors. The hydraulic control mechanism is connected to the thrust cylinder and the power head to supply fluid to the thrust cylinder and the power head.

[0011] According to another aspect of the present invention, a method for simulating the full-face drilling environment of a raise boring machine is also provided, comprising the following steps:

[0012] S1. Extract rock hardness data from the actual drilling location;

[0013] S2. Create a simulated rock block and evenly place several pressure sensors around the circumference of the experimental borehole inside the simulated rock block.

[0014] S3. Set the drilling parameters for the experimental drilling rig;

[0015] The drilling parameters include: single drilling depth h, total number of drilling experiments n, drilling speed Vm during each drilling operation, drill bit rotation speed Sm, thrust fm, rotational torque Tm, and high-pressure well-washing fluid pressure Pm for flushing drill cuttings during each drilling operation, where m is an integer, 1≤m≤n.

[0016] S4. Complete each drilling operation sequentially, and after each experimental drilling operation, measure the cutter wear amount δm, 1≤m≤n, and obtain the wellbore pressure data P measured by all pressure sensors. Further obtain the maximum value P(max) among the wellbore pressure data, and determine whether P(max) is greater than or equal to Pm*80%. If the first measurement shows that P(max) ≥ Pm*80%, then Pm is determined to be the critical pressure value. The actual drilling depth Hm corresponding to Pm is the critical drilling depth Ho for wellbore maintenance.

[0017] S5. After completing all drilling tests, obtain the optimal drilling speed Vo, the optimal cutter wear δo, the corresponding optimal thrust fo and optimal rotational torque To, and the critical drilling depth Ho for wellbore maintenance that best match the actual drilling conditions.

[0018] The aforementioned full-section drilling environment simulation experimental equipment and method for raise boring machines simulates actual drilling conditions by setting up a base, a high-pressure sealing seat, and an experimental drilling rig dynamically sealed to the high-pressure sealing seat. Simulated rock blocks matching the hardness data of the actual drilling area are placed inside the base, and a return fluid channel is set inside the drill pipe. Through the experimental simulation process of actual drilling conditions, the drilling pressure is measured by a first strain gauge pressure sensor, the rotational torque is measured by a second strain gauge pressure sensor, the drilling speed is measured by a displacement sensor, and the drilling speed is measured by a rotary encoder. Measuring the drill bit rotation speed allows for the acquisition of the optimal drilling speed, optimal cutter wear, and corresponding optimal thrust and rotational torque that match actual working conditions. Furthermore, by installing several pressure sensors within the simulated rock block, the pressure data of the wellbore under high-pressure flushing fluid is monitored, providing parameters for whether the wellbore is damaged. This data supports whether wellbore maintenance is needed in actual drilling conditions and where to begin maintenance. Compared with existing technologies, this invention achieves the simulation of construction conditions and the prediction of construction parameters when using a raise boring machine for well construction, thereby improving construction efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0020] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0021] Figure 3 This is a three-dimensional structural diagram of the present invention (the base and simulated rock block are not shown in the figure).

[0022] In the diagram: Base 1; Simulated rock block 2; High-pressure sealing seat 3; Flange 30; Top cover 31; High-pressure chamber 32; Sealing assembly 33; Drill frame 40; Slide rail 400; Drill rig main unit 41; Thrust cylinder 410; Power head housing 411; Power head 412; Hydraulic motor 4120; Transmission gear set 4121; Power head spindle 413; Drill rod 414; Inner layer drill rod 4140; Middle layer drill rod 4141; Outer layer drill rod 4142; Drill bit 415; Cutterhead 4150; Roller cutter 4151; Liquid inlet channel 4160; Liquid return channel 4161; Well washing fluid inlet 4162; Well washing fluid outlet 4163; Slag discharge inlet 4164; Slag discharge outlet 4165; Control center 42; Hydraulic control mechanism 43; Well washing fluid supply mechanism 44; Slag receiving mechanism 45; First strain gauge pressure sensor 460; Second strain gauge pressure sensor 461; Pressure sensor 463; Wireless transmission module 464; Connector 465. Detailed Implementation

[0023] The technical solutions and effects of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Please refer to Figure 1-3 In a typical embodiment of the present invention, a full-section drilling environment simulation experimental device for a reverse drilling rig is provided, comprising: a base 1, a simulated rock block 2, a high-pressure sealing seat 3, and an experimental drilling rig.

[0025] The base 1 is cylindrical and its bottom is fixed to the ground. The simulated rock block 2 is placed inside the base 1 and its shape matches the inner cavity of the base 1. The high-pressure sealing seat 3 is bottomless and hollow. The bottom of the high-pressure sealing seat 3 is sealed and connected to the top of the base 1 through a flange 30. The top of the high-pressure sealing seat 3 is provided with a top cover 31, which is connected to the experimental drill motor seal. A high-pressure cavity 32 is formed inside the high-pressure sealing seat 3.

[0026] The experimental drilling rig includes: a drill frame 40, a drilling rig main unit 41, a control center 42, a hydraulic control mechanism 43, a well washing fluid supply mechanism 44, a slag receiving mechanism 45, and a monitoring mechanism;

[0027] The bottom of the drill frame 40 is fixedly connected to the top cover of the high-pressure sealing seat 3; the main body of the drilling rig 41 includes: a thrust cylinder 410, a power head housing 411, a power head 412, a power head spindle 413, a drill rod 414, and a drill bit 415;

[0028] The drill frame 40 is equipped with a slide rail 400, and the power head housing 411 is fitted onto the slide rail 400. The power head housing 411 and the drill frame 40 are slidably connected vertically. The power head 412 is fixed in the center of the power head housing 411. The cylinders of the thrust cylinders 410 are symmetrically fixed around the power head housing 411, and the piston rods of the thrust cylinders 410 are symmetrically fixed around the bottom of the drill frame 40. The thrust cylinders 410 drive the power head housing 411 and the power head 412 to slide vertically along the drill frame 40. The power head spindle 413 is mounted on the power head housing 411. Inside the head 412, the power head spindle 413 is hollow; the drill pipe 414 is mounted on the power head spindle 413; the power head spindle 413 rotates and moves axially under the drive of the power head 412, simultaneously driving the drill pipe 414 to rotate and move axially; the drill pipe 414 includes: a middle layer drill pipe 4141 and an inner layer drill pipe 4140; the upper end of the middle layer drill pipe 4141 is connected to the power head spindle 413, and the lower end of the middle layer drill pipe 4141 is connected to the drill bit 415, used to transmit drilling pressure and rotational torque; the inner layer drill pipe 4140 is mounted on the power head spindle 413. Inside the power head spindle 413 and the intermediate drill pipe 4141, a gap is left between the outer wall of the inner drill pipe 4140 and the inner walls of the power head spindle 413 and the intermediate drill pipe 4141, forming a fluid inlet channel 4160. A well-washing fluid inlet 4162 is provided at the upper end of the fluid inlet channel 4160, and the lower end of the fluid inlet channel 4160 is connected to the drill bit 415. The well-washing fluid inlet 4160 is connected to the well-washing fluid supply mechanism 44 through a pipe, and... High-pressure well-washing fluid is delivered to drill bit 415; the inner drill pipe 4140 is hollow inside, forming a return fluid channel 4161; the upper part of the inner drill pipe 4140 is fixedly connected to the power head box 411, and the lower end of the inner drill pipe 4140 passes through drill bit 415 and extends into high-pressure chamber 32, becoming the slag discharge inlet 4164 after the high-pressure well-washing fluid washes the well wall; the upper end of the inner drill pipe 4140 is provided with slag discharge outlet 4165, and the slag discharge outlet 4165 is connected to the inlet of slag receiving mechanism 45 through a pipeline, so as to deliver the high-pressure well-washing fluid after washing the well wall to slag receiving mechanism 45;

[0029] Since the upper part of the inner drill rod 4140 is fixedly connected to the power head housing 411, the inner drill rod 4140 remains fixed when the inner drill rod 4141 rotates under the drive of the power head spindle 413.

[0030] The monitoring mechanism includes: a first strain gauge pressure sensor 460, a second strain gauge pressure sensor 461, a displacement sensor (not shown in the figure), a rotary encoder (not shown in the figure), and several pressure sensors 463; the first strain gauge pressure sensor 460 is disposed on the connection surface of the drill bit 415 and the connecting seat 465 of the drill rod 414, and is used to measure the drilling pressure to monitor the thrust of the thrust cylinder 410; the second strain gauge pressure sensor 461 is disposed on the outer circumference of the connecting seat 465 of the drill bit 415 and the drill rod 414, and is used to measure the rotational torque; the displacement sensor is disposed on the thrust cylinder 410, and is used to measure the drilling speed; the rotary encoder is disposed on the power head 412, and is used to measure the rotational speed provided by the power head to obtain the drill bit rotational speed; several pressure sensors 463 are evenly distributed around the circumference of the experimental borehole in the simulated rock block, and are used to measure the well wall pressure data, with the pressure sensors 463 being 10-15mm away from the well wall of the experimental borehole;

[0031] Since the drilling pressure of drill bit 415 is related to the thrust of thrust cylinder 410, the thrust of thrust cylinder 410 is monitored by measuring the drilling pressure; since the rotational speed of drill bit 415 is related to the rotational power provided by power head 412, the drill bit rotational speed is obtained by measuring the rotational speed provided by power head 412 by setting a rotary encoder on power head 412.

[0032] The control center 42 is communicatively connected to the hydraulic control mechanism 43, the well-washing fluid supply mechanism 44, the first strain gauge pressure sensor 460, the second strain gauge pressure sensor 461, the displacement sensor, the rotary encoder, and several pressure sensors 463. The hydraulic control mechanism 43 is connected to the thrust cylinder 410 and the power head 412 to supply fluid to the thrust cylinder 410 and the power head 412. The well-washing fluid supply mechanism 44 includes a pressurization component (not shown in the figure) for pressurizing the well-washing fluid.

[0033] In this embodiment, the high-pressure sealing seat 3, the base 1 installed below, and the top cover 31 above form a high-pressure chamber 32. A dynamic seal is formed between the top cover 31 and the drill rod 414. The drill rod 414 rotates and moves axially under the drive of the power head spindle 413. At the same time, the operator controls the well-washing fluid supply mechanism 44 through the control center 42 to supply high-pressure well-washing fluid to the experimental drilling rig. The high-pressure well-washing fluid enters the inlet channel 4160 through the well-washing fluid inlet 4162 and enters the high-pressure chamber 32 through the well-washing fluid outlet, which cooperates with the drilling of the drill bit 415 to flush the drill cuttings. After the high-pressure well-washing fluid flushes the drill cuttings, it enters the return channel 4161 through the slag discharge inlet 4164 and is finally discharged into the slag receiving mechanism 45 through the slag discharge outlet 4165, realizing the simulation of the working environment of the drill bit 415 in the high-pressure well-washing fluid.

[0034] In this embodiment, since the height of the simulated rock block 2 cannot match the well depth in actual drilling conditions, a pressurization component is set in the well-washing fluid supply mechanism 44 to pressurize the well-washing fluid. On the one hand, this simulates the pressure generated by the well-washing fluid due to the well depth in actual drilling conditions. On the other hand, by pressurizing the well-washing fluid, the well-washing fluid can enter the return fluid channel 4161 from the slag discharge inlet 4164 due to the applied pressure, and then be discharged from the slag discharge outlet 4165.

[0035] Further, please see Figure 1 In order to improve the utilization rate of the well washing fluid and save resources, a filter module (not shown in the figure) is installed in the slag receiving mechanism 45. The outlet of the slag receiving mechanism 45 is connected to the well washing fluid supply mechanism 44. The slag receiving mechanism 45 filters the high-pressure well washing fluid after flushing the well wall through the filter module and sends it to the well washing fluid supply mechanism 44 for recycling.

[0036] Further, please see Figure 1-2 To improve the security and accuracy of data transmission and avoid the impact of experimental conditions on data transmission, the drill rod also includes an outer drill rod 4142, which is fitted outside the middle drill rod 4141. A gap is left between the inner wall of the outer drill rod 4142 and the outer wall of the middle drill rod 4141, so that an annular cavity is formed between the inner wall of the outer drill rod 4142 and the outer wall of the middle drill rod 4141 for setting the connection line of the monitoring mechanism.

[0037] The monitoring mechanism further includes: a wireless transmission module 464, disposed on the upper outer side of the outer drill pipe 4142; the input end of the wireless transmission module 464 is communicatively connected to the first strain gauge pressure sensor 460 and the second strain gauge pressure sensor 461 via connecting lines, and the output end of the wireless transmission module 464 is wirelessly connected to the control center 42; the wireless transmission module 464 transmits the drilling pressure received from the first strain gauge pressure sensor 460 and the rotational torque received from the second strain gauge pressure sensor 461 to the control center 42 wirelessly; the connecting line is disposed in the annular cavity formed between the inner wall of the outer drill pipe 4142 and the outer wall of the middle drill pipe 4141 to ensure the quality of signal transmission; the displacement sensor is a wireless displacement sensor; the rotary encoder is a wireless encoder sensor; the pressure sensor 463 is a wireless pressure sensor; the displacement sensor, rotary encoder, and pressure sensor are wirelessly connected to the control center 42.

[0038] By setting the outer drill pipe 4142, an annular cavity is formed between the inner wall of the outer drill pipe 4142 and the outer wall of the middle drill pipe 4141, so that the connection line of the monitoring mechanism from the drill bit 415 to the wireless transmission module 464 can be transmitted through this annular cavity, avoiding the influence of the well washing fluid on the transmitted data and ensuring the accuracy and security of data transmission.

[0039] Further, please see Figure 2 The drill bit 415 includes a cutterhead 4150 and a roller cutter 4151; the fluid inlet channel 4160 is connected to the cutterhead 4150, and the lower end face of the cutterhead 4150 has a well-washing fluid outlet 4163.

[0040] Further, please see Figure 3 A sealing assembly 33 is provided on the top cover 31, and the drill rod 414 is dynamically sealed by the sealing assembly 33 and the high-pressure sealing seat 3.

[0041] Further, please see Figure 3 The power head 412 includes a hydraulic motor 4120 and a transmission gear set 4121. The input end of the transmission gear set 4121 is connected to the output end of the hydraulic motor 4120, and the output end of the transmission gear set 4121 is connected to the power head spindle 413. The hydraulic motor 4120 transmits power to the power head spindle 413 through the transmission gear set 4121, and drives the power head spindle 413 and the intermediate drill rod 4141 connected to the power head spindle 413 to rotate, thereby driving the drill bit 415 to rotate.

[0042] Furthermore, the rotary encoder is mounted on the hydraulic motor 4120 of the power head 412.

[0043] The working principle and process of the full-section drilling environment simulation experimental equipment for the raise boring machine provided in this specific embodiment are as follows:

[0044] First, the workers placed the simulated rock block 2 inside the base 1;

[0045] Secondly, the operator controls the hydraulic control mechanism 43 through the control center 42 to supply hydraulic fluid to the thrust cylinder 410 and the hydraulic motor 4120. The thrust cylinder 410 drives the power head housing 411, which in turn drives the power head 412 and the power head spindle 413 to move axially. At the same time, the hydraulic motor 4120 transmits the rotational torque to the power head spindle 413 through the transmission gear set 4121, and the power head spindle 413 rotates. Driven by the power head spindle 413, the drill rod 414 drives the drill bit 415 to rotate and move axially, simulating the actual drilling operation of the drilling rig.

[0046] Then, when the drill bit 415 is drilling, the operator controls the well-washing fluid mechanism 44 through the control center 42 to supply high-pressure well-washing fluid. The high-pressure well-washing fluid enters the fluid inlet channel 4160 between the outer wall of the inner drill pipe 4140, the inner wall of the middle drill pipe 4141, and the inner wall of the power head spindle 413 through the well-washing fluid inlet 4162. It then enters the high-pressure chamber through the well-washing fluid outlet 4163. After flushing the drill cuttings in the high-pressure chamber 32 in conjunction with the drilling of the drill bit 415, it enters the return fluid channel 4161 inside the inner drill pipe 4140 through the slag discharge inlet 4164. Finally, it is discharged into the slag receiving mechanism 45 through the slag discharge outlet 4165.

[0047] Finally, the washing fluid containing drilling cuttings enters the cuttings receiving mechanism 45, is filtered by the filtration module, and then re-enters the washing fluid supply mechanism 44 for recycling.

[0048] During the drilling process, the operator sets the fluid supply to the thrust cylinder 410 and hydraulic motor 4120 through the control center 42. At the same time, the first strain gauge pressure sensor 460 and the second strain gauge pressure sensor 461 set in the monitoring mechanism monitor the thrust and rotational torque respectively, so as to control the thrust and rotational torque when the drill bit 415 is drilling. Meanwhile, since the thrust is related to the drilling speed and the rotational torque is related to the drill bit speed, the control center 42 monitors the drilling speed and the drill bit speed respectively through the displacement sensor and rotary encoder of the monitoring mechanism, so as to better regulate the fluid supply to the thrust cylinder 410 and hydraulic motor 4120.

[0049] In another typical embodiment of the present invention, using the above-mentioned full-section drilling environment simulation experimental equipment for a raise boring machine, a method for simulating the full-section drilling environment of a raise boring machine is also provided, comprising the following steps:

[0050] S1. Extract rock hardness data from the actual drilling location;

[0051] S2. Create a simulated rock block 2, and evenly place several pressure sensors 463 around the circumference of the experimental borehole inside the simulated rock block 2; the simulated rock block 2 matches the rock hardness data of the actual drilling location.

[0052] S3. Set the drilling parameters for the experimental drilling rig;

[0053] The drilling parameters include: single drilling depth h, total number of drilling experiments n, drilling speed Vm during each drilling operation, drill bit rotation speed Sm, thrust fm, rotational torque Tm, and high-pressure well-washing fluid pressure Pm for flushing drill cuttings during each drilling operation, where m is an integer, 1≤m≤n.

[0054] S4. Complete each drilling operation sequentially, and after each experimental drilling operation, measure the cutter wear amount δm, 1≤m≤n, and obtain the wellbore pressure data P measured by all pressure sensors. Further obtain the maximum value P(max) among the wellbore pressure data, and determine whether P(max) is greater than or equal to Pm*80%. If the first measurement shows that P(max) ≥ Pm*80%, then Pm is determined to be the critical pressure value. The actual drilling depth Hm corresponding to Pm is the critical drilling depth Ho for wellbore maintenance.

[0055] S5. After completing all drilling tests, obtain the optimal drilling speed Vo, the optimal cutter wear δo, the corresponding optimal thrust fo and optimal rotational torque To, and the critical drilling depth Ho for wellbore maintenance that best match the actual drilling conditions.

[0056] In actual drilling operations, when the cutter wear reaches 5mm, operations must be paused and the cutters replaced. Replacing the cutters requires removing the drill pipe, a cumbersome process that consumes significant time and manpower. Therefore, to achieve the fastest drilling speed and optimal cutter wear, it's crucial to minimize cutter replacements. This requires a comprehensive approach that matches the drilling speed with the corresponding cutter wear. The total cutter wear during actual drilling can be determined based on the cutter wear observed in drilling experiments and the actual drilling depth. The number of cutter replacements required in actual drilling operations can then be calculated based on this total wear.

[0057] Wellbore maintenance is required at all drilling depths below the critical drilling depth.

[0058] Furthermore, in step S2, the pressure sensor is 10-15 mm away from the well wall of the experimental borehole.

[0059] Furthermore, in step S3, the steps for setting the drilling parameters are as follows:

[0060] S31. Based on the hardness data of the sampled rock, set the single drilling depth h of the experimental drilling rig and the total number of drilling experiments n;

[0061] S32. Based on the total number of drilling experiments n, the actual total drilling depth H is divided into n segments, and the actual well-washing fluid pressure corresponding to the depth of each segment is set to the high-pressure well-washing fluid pressure Pm of the experimental drilling rig during each drilling.

[0062] S32. The hydraulic control mechanism is controlled by the control center to supply fluid to the thrust cylinder and the power head, so as to obtain the preset drilling speed Vm and drill bit speed Sm for each time, and record the corresponding thrust fm and rotational torque Tm.

[0063] Furthermore, in step S31, if the sampled rock hardness is greater than or equal to 40 MPa, the single drilling depth h is set to 100 mm; if the sampled rock hardness is less than 40 MPa, the single drilling depth h is set to 200 mm; the total number of drilling operations is set to 10 to 15.

[0064] The beneficial effects of the present invention will be further described in detail below with reference to specific embodiments.

[0065] Example 1, Example 2

[0066] The full-section drilling environment simulation experimental equipment for reverse drilling rigs provided by this invention was used, along with the full-section drilling environment simulation experimental method for reverse drilling provided by this invention. In Example 1, the rock hardness of the actual drilling location was 150 MPa, the actual total drilling depth was 100 m, and the simulated rock hardness was set to 150 MPa. The single drilling depth h was 100 mm, and the total number of drilling experiments n was 10. The drilling parameters for each drilling experiment, including thrust, drilling speed, drill bit speed, rotational torque, cutter wear after each drilling, and the corresponding number of cutter replacements in actual drilling, are detailed in Table 1. The actual total drilling depth was divided into 10 segments, and the high-pressure flushing fluid pressure and pressure of each segment were also detailed. The maximum value P(max) of the wellbore pressure data measured by the force sensor is shown in Table 2. In Example 2, the rock hardness of the actual drilling location was 35 MPa, the actual total drilling depth was 200 m, and in the simulation experiment, the hardness of the simulated rock block was set to 35 MPa, the single drilling depth was 200 mm, and the total number of drilling experiments n was 10. The drilling parameters during each drilling experiment, including thrust, drilling speed, drill bit speed, rotational torque, cutter wear after each drilling, and the corresponding number of cutter replacements in the actual drilling, are shown in Table 3. The actual total drilling depth was divided into 10 segments, and the pressure of the high-pressure washing fluid corresponding to each segment and the maximum value P(max) of the wellbore pressure data measured by the pressure sensor are shown in Table 4.

[0067] Table 1

[0068]

[0069]

[0070] Table 2

[0071]

[0072] Table 3

[0073]

[0074]

[0075] Table 4

[0076]

[0077] The optimal drilling speed and optimal cutter wear are obtained by combining the drilling speed with the corresponding cutter wear, based on a comprehensive principle.

[0078] As shown in Table 1, in Example 1, the optimal drilling speed Vo is 8.1 mm / min, the optimal cutter wear δo is 4.9 μm / 100 mm, the corresponding optimal thrust fo is 190 kN, and the optimal rotational torque To is 73 kN.m. According to Table 2, when P(max) ≥ Pm*80% for the first time, the actual drilling depth Hm corresponding to Pm is 80 m. Therefore, the critical drilling depth Ho for wellbore maintenance is 80 m.

[0079] As shown in Table 3, in Example 2, the optimal drilling speed Vo is 10.6 mm / min, the optimal cutter wear δo is 4.8 μm / 200 m, the corresponding optimal thrust fo is 170 kN, and the optimal rotational torque To is 64 kN·m. According to Table 4, when P(max) ≥ Pm*80% for the first time, the actual drilling depth Hm corresponding to Pm is 60 m. Therefore, the critical drilling depth Ho for wellbore maintenance is 60 m.

[0080] The aforementioned full-section drilling environment simulation experimental equipment and method for raise boring machines simulates actual drilling conditions by setting up a base, a high-pressure sealing seat, and an experimental drilling rig dynamically sealed to the high-pressure sealing seat. Simulated rock blocks matching the hardness data of the actual drilling area are placed inside the base, and a return fluid channel is set inside the drill pipe. Through the experimental simulation process of actual drilling conditions, the drilling pressure is measured by a first strain gauge pressure sensor, the rotational torque is measured by a second strain gauge pressure sensor, the drilling speed is measured by a displacement sensor, and the drilling speed is measured by a rotary encoder. Measuring the drill bit rotation speed allows for the acquisition of the optimal drilling speed, optimal cutter wear, and corresponding optimal thrust and rotational torque that match actual working conditions. Furthermore, by installing several pressure sensors within the simulated rock block, the pressure data of the wellbore under high-pressure flushing fluid is monitored, providing parameters for whether the wellbore is damaged. This data supports whether wellbore maintenance is needed in actual drilling conditions and where to begin maintenance. Compared with existing technologies, this invention achieves the simulation of construction conditions and the prediction of construction parameters when using a raise boring machine for well construction, thereby improving construction efficiency.

[0081] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for simulating the full-section drilling environment of a raise boring machine, characterized in that, The following is a full-section drilling environment simulation experimental equipment for a raise boring machine, including: a base, simulated rock blocks, a high-pressure sealing seat, and the experimental drilling machine; The base is cylindrical and its bottom is fixed to the ground. Simulated rock blocks are placed inside the base. The high-pressure sealing seat is bottomless and hollow. The bottom of the high-pressure sealing seat is sealed to the top of the base through a flange. A top cover is provided on the top of the high-pressure sealing seat. The top cover is mechanically sealed to the experimental drill. A high-pressure chamber is formed inside the high-pressure sealing seat. A sealing component is provided on the top cover. The experimental drilling rig includes: drill frame, drilling rig main unit, control center, hydraulic control mechanism, well washing fluid supply mechanism, slag receiving mechanism, and monitoring mechanism; The drill frame bottom is fixedly connected to the top cover of the high-pressure sealing seat; the main body of the drilling rig includes: a thrust cylinder, a power head housing, a power head, a power head spindle, a drill rod, and a drill bit; the drill rod is dynamically sealed by a sealing assembly and a high-pressure sealing seat; It also includes the following steps: S1. Extract rock hardness data from the actual drilling location; S2. Create a simulated rock block and evenly place several pressure sensors around the circumference of the experimental borehole inside the simulated rock block. S3. Set the drilling parameters for the experimental drilling rig; The drilling parameters include: single drilling depth h, total number of drilling experiments n, drilling speed Vm during each drilling operation, drill bit rotation speed Sm, thrust fm, rotational torque Tm, and high-pressure well-washing fluid pressure Pm for flushing drill cuttings during each drilling operation, where m is an integer, 1≤m≤n. S4. Complete each drilling operation sequentially, and after each experimental drilling operation, measure the cutter wear amount δm, 1≤m≤n, and obtain the wellbore pressure data P measured by all pressure sensors. Further obtain the maximum value P(max) among the wellbore pressure data, and determine whether P(max) is greater than or equal to Pm×80%. When P(max) is measured to be ≥ Pm×80% for the first time, Pm is determined to be the critical pressure value. The actual drilling depth Hm corresponding to Pm is the critical drilling depth Ho for wellbore maintenance. S5. After completing all drilling tests, obtain the optimal drilling speed Vo, the optimal cutter wear δo, the corresponding optimal thrust fo and optimal rotational torque To, and the critical drilling depth Ho for well wall maintenance that best match the actual drilling conditions. In step S3, the steps for setting the drilling parameters are as follows: S31. Based on the hardness data of the sampled rock, set the single drilling depth h of the experimental drilling rig and the total number of drilling experiments n; S32. Based on the total number of drilling experiments n, the actual total drilling depth H is divided into n segments, and the actual well-washing fluid pressure corresponding to the depth of each segment is set to the high-pressure well-washing fluid pressure Pm of the experimental drilling rig during each drilling. S32. The hydraulic control mechanism is controlled by the control center to supply fluid to the thrust cylinder and the power head, so as to obtain the preset drilling speed Vm and drill bit speed Sm for each time, and record the corresponding thrust fm and rotational torque Tm.

2. The full-section drilling environment simulation experimental method for raise boring machines as described in claim 1, characterized in that: The power head housing and drill frame are slidably connected vertically; the power head is fixed in the center of the power head housing; the cylinders of the thrust cylinders are symmetrically fixed around the power head housing, and the piston rods of the thrust cylinders are symmetrically fixed around the bottom of the drill frame. The thrust cylinders drive the power head housing and the power head to slide vertically along the drill frame; the power head spindle is located inside the power head, and the inside of the power head spindle is hollow; the drill rod is fitted onto the power head spindle; the power head spindle rotates and moves axially under the drive of the power head, simultaneously driving the drill rod to rotate and move axially; the drill rod includes: a middle drill rod and an inner drill rod; the upper end of the middle drill rod is connected to the power head spindle, and the lower end of the middle drill rod is connected to the drill bit, used to transmit drilling pressure and rotational torque; the inner drill rod is fitted inside the power head spindle and the middle drill rod, and the inner drill rod... A gap is left between the outer wall of the inner drill rod and the inner wall of the power head spindle and the inner wall of the middle drill rod, so that a fluid inlet channel is formed between the outer wall of the inner drill rod and the inner wall of the power head spindle and the inner wall of the middle drill rod. A well-washing fluid inlet is set at the upper end of the fluid inlet channel, and the lower end of the fluid inlet channel is connected to the drill bit. The well-washing fluid inlet is connected to the well-washing fluid supply mechanism through a pipeline, and the high-pressure well-washing fluid is sent to the drill bit. A well-washing fluid outlet is set on the drill bit. The inner drill rod is hollow inside, forming a return fluid channel. The upper part of the inner drill rod is fixedly connected to the power head housing. The lower end of the inner drill rod passes through the drill bit and extends into the high-pressure chamber, becoming the slag discharge inlet after the high-pressure well-washing fluid washes the well wall. A slag discharge outlet is set at the upper end of the inner drill rod. The slag discharge outlet is connected to the inlet of the slag receiving mechanism through a pipeline, and the high-pressure well-washing fluid after washing the well wall is sent to the slag receiving mechanism. The monitoring mechanism includes: a first strain gauge pressure sensor, a second strain gauge pressure sensor, a displacement sensor, a rotary encoder, and several pressure sensors; the first strain gauge pressure sensor is installed on the connection surface between the drill bit and the drill pipe connecting seat to measure the drilling pressure and monitor the thrust of the thrust cylinder; the second strain gauge pressure sensor is installed on the outer circumference of the connection seat between the drill bit and the drill pipe to measure the rotational torque; the displacement sensor is installed on the thrust cylinder to measure the drilling speed; the rotary encoder is installed on the power head to measure the rotational speed provided by the power head to obtain the drill bit rotational speed; several pressure sensors are evenly distributed around the circumference of the experimental borehole within the simulated rock block to measure the wellbore bearing pressure data; The control center is connected to the hydraulic control mechanism, the well-washing fluid supply mechanism, the first strain gauge pressure sensor, the second strain gauge pressure sensor, the displacement sensor, the rotary encoder, and several pressure sensors. The hydraulic control mechanism is connected to the thrust cylinder and the power head to supply fluid to the thrust cylinder and the power head.

3. The full-section drilling environment simulation experimental method for raise boring machines as described in claim 1, characterized in that: The slag receiving mechanism is equipped with a filtration module. The outlet of the slag receiving mechanism is connected to the well washing fluid supply mechanism. The slag receiving mechanism filters the high-pressure well washing fluid after flushing the well wall through the filtration module and sends it to the well washing fluid supply mechanism for recycling.

4. The full-section drilling environment simulation experimental method for raise boring machines as described in claim 2, characterized in that: The drill rod also includes an outer drill rod, which is fitted outside the middle drill rod. There is a gap between the inner wall of the outer drill rod and the outer wall of the middle drill rod, so that an annular cavity is formed between the inner wall of the outer drill rod and the outer wall of the middle drill rod, which is used to set the connection line of the monitoring mechanism. The monitoring mechanism further includes: a wireless transmission module disposed on the upper outer side of the outer drill pipe; the input end of the wireless transmission module is communicatively connected to the first strain gauge pressure sensor and the second strain gauge pressure sensor via connecting lines, and the output end of the wireless transmission module is wirelessly connected to the control center; the connecting lines are disposed in the annular cavity formed between the inner wall of the outer drill pipe and the outer wall of the middle drill pipe to ensure the quality of signal transmission; the displacement sensor is a wireless displacement sensor; the rotary encoder is a wireless encoder sensor; the pressure sensor is a wireless pressure sensor; the displacement sensor, the rotary encoder, and the pressure sensor are all wirelessly connected to the control center.

5. The full-section drilling environment simulation experimental method for a raise boring machine as described in claim 2, characterized in that: The drill bit includes a cutterhead and a rotary cutter; the fluid inlet channel is connected to the cutterhead, and a well-washing fluid outlet is provided on the lower end face of the cutterhead.

6. The method for simulating the full-section drilling environment of a raise boring machine as described in claim 2, characterized in that: The power head includes a hydraulic motor and a transmission gear set; the input end of the transmission gear set is connected to the output end of the hydraulic motor, and the output end of the transmission gear set is connected to the main shaft of the power head; the hydraulic motor transmits power to the main shaft of the power head through the transmission gear set, and drives the main shaft of the power head and the intermediate drill rod connected to the main shaft of the power head to rotate, thereby driving the drill bit to rotate.

7. The full-section drilling environment simulation experimental method for a raise boring machine as described in claim 6, characterized in that: The rotary encoder is mounted on the hydraulic motor of the power head.

8. The full-section drilling environment simulation experimental method for a raise boring machine as described in claim 1, characterized in that: In step S2, the pressure sensor is 10-15 mm away from the well wall of the experimental borehole.

9. The full-section drilling environment simulation experimental method for a raise boring machine as described in claim 1, characterized in that: In step S31, if the hardness of the sampled rock is greater than or equal to 40 MPa, the single drilling depth h is set to 100 mm; if the hardness of the sampled rock is less than 40 MPa, the single drilling depth h is set to 200 mm; the total number of drilling operations is set to 10-15.

Images