PDC drill bit cutting tooth rock breaking test device

Abstract

According to the PDC drill bit cutting tooth rock breaking test device, a test container serves as a core bearing structure, a pressure control system is communicated with the test container, pressurization, pressure relief and pressure stabilization can be conducted on the interior of the container, confining pressure environments of different depths underground are simulated, the stability and adjustability of pressure conditions in the test process are ensured, and the test efficiency is improved. The bit pressure loading system is fixed in the test container, is connected with a drill bit and can apply force loading and displacement loading to the drill bit at the same time and simulate dynamic mechanical behaviors in the actual drilling process, and the rock sample rotation driving system is fixed in the test container, drives a rock sample to rotate and simulates relative movement when the drill bit cuts rock. The heating system is communicated with the test container, the underground high-temperature environment is simulated through heating, cooling, oil injection and oil discharge of heat conduction oil, the temperature uniformity and stability are ensured, the rock cutting process of the PDC drill bit can be simulated more truly under the high-temperature and high-pressure conditions, and the accuracy of test data is improved.

Description

Technical Field

[0001] The present application relates to the field of rock breaking tests of PDC drill bit cutters, and in particular to a rock breaking test device for PDC drill bit cutters. Background Art

[0002] The PDC drill cutter rock-breaking test system is a specialized experimental system used to simulate and study the mechanical behavior, efficiency, and process adaptability of polycrystalline diamond compact (PDC) cutters during rock crushing. By controlling parameters (such as cutting depth, rotational speed, and confining pressure), the rock-breaking process of PDC cutters under various geological conditions is simulated, with a focus on studying the rock shearing and crushing mechanisms of single or multiple cutters working in concert.

[0003] In the related technology, the original PDC drill bit cutting tooth rock breaking test device is used, which cannot truly reflect the impact of temperature and pressure on the PDC drill bit when cutting rock in the underground high temperature and high pressure environment, and the conclusions drawn from the test are easily distorted. Summary of the Invention

[0004] The present application provides a PDC drill bit cutting tooth rock breaking test device, which can solve the technical problem that the traditional PDC drill bit cutting tooth rock breaking test device cannot truly reflect the impact of temperature and pressure on the PDC drill bit when cutting rock in an underground high temperature and high pressure environment, and the conclusions drawn from the test are easily distorted.

[0005] In a first aspect, an embodiment of the present application provides a PDC drill bit cutter rock breaking test device, comprising: Test container; a pressure control system, the pressure control system being in communication with the test container and configured to pressurize, relieve, and stabilize the test container; A weight-on-bit loading system, the weight-on-bit loading system being disposed in the test container and being fixed to the drill bit and configured to apply force loading and displacement loading to the drill bit; a rock sample rotation drive system, the rock sample rotation drive system being disposed in the test container, the rock sample rotation drive system being used to be fixed to the rock sample and configured to drive the rock sample to rotate; A heating system is communicated with the test container and is configured to heat, cool, fill and drain the heat transfer oil in the test container.

[0006] In one embodiment, the pressure control system comprises: Oil tank 1, wherein the output end of the oil tank 1 is connected to variable displacement pump 1; A servo reversing valve 1, wherein the pressure oil inlet of the servo reversing valve 1 is connected to the output end of the variable pump 1, and the oil return port of the servo reversing valve 1 is connected to the oil tank 1; a supercharger, wherein the first actuator connection port of the servo reversing valve 1 is in communication with the right chamber of the supercharger, and the second actuator connection port of the servo reversing valve 1 is in communication with the left chamber of the supercharger, the left chamber of the supercharger is in communication with the test container via a fifth one-way valve, and the right chamber of the supercharger is in communication with the test container via a fourth one-way valve; Fuel tank 2 is connected to the left chamber of the supercharger via a second one-way valve, and is connected to the right chamber of the supercharger via a third one-way valve.

[0007] In one embodiment, the pressure control system further comprises: A pressure needle valve 1, wherein the oil tank 2 is connected to the test container via the pressure needle valve 1.

[0008] In one embodiment, the pressure control system further comprises: a proportional pressure reducing valve, wherein the oil inlet of the proportional pressure reducing valve is connected to the output end of the variable pump 1, and the oil discharge port of the proportional pressure reducing valve is connected to the oil tank 1; an electromagnetic reversing valve, wherein the pressure oil inlet of the electromagnetic reversing valve is connected to the oil outlet of the proportional pressure reducing valve, and the oil return port of the electromagnetic reversing valve is connected to the oil tank; A pressure regulator, the first actuator connection port of the electromagnetic reversing valve is connected to the first lower chamber interface of the pressure regulator, the second actuator connection port of the electromagnetic reversing valve is connected to the second lower chamber interface of the pressure regulator, the first upper chamber interface of the pressure regulator is connected to the test container, and the oil tank 2 is connected to the second upper chamber interface of the pressure regulator via the first one-way valve.

[0009] In one embodiment, the weight-on-bit loading system comprises: Oil tank three, wherein a variable displacement pump two is installed at the output end of the oil tank three; a second servo reversing valve, wherein the pressure oil inlet of the second servo reversing valve is connected to the output end of the second variable displacement pump, and the oil return port of the second servo reversing valve is connected to the third oil tank; a loading cylinder, wherein the left chamber of the loading cylinder is in communication with the first actuator connection port of the second servo reversing valve, and the right chamber of the loading cylinder is in communication with the second actuator connection port of the second servo reversing valve; A proportional relief valve installed between the left chamber of the loading cylinder and the first actuator connection port of the second servo reversing valve; A loading rod is fixed to the piston rod of the loading cylinder, and the loading rod is used to be fixed to the rock sample.

[0010] In one embodiment, a pressure sensor is installed on the end surface of the loading rod of the loading cylinder.

[0011] In one embodiment, the rock sample rotation drive system comprises: Oil tank four, the output end of which is connected to variable displacement pump three; an electro-hydraulic proportional reversing valve, wherein the pressure oil inlet of the electro-hydraulic proportional reversing valve is connected to the output end of the variable pump three, and the oil return port of the electro-hydraulic proportional reversing valve is connected to the oil tank four; A hydraulic motor, wherein the input end of the hydraulic motor is communicated with the first actuator connection port of the electro-hydraulic proportional reversing valve, and the output end of the hydraulic motor is communicated with the second actuator connection port of the electro-hydraulic proportional reversing valve.

[0012] In one embodiment, the rock sample rotation drive system further comprises: The pressure compensator is installed on the electro-hydraulic proportional reversing valve; A rotation speed sensor is installed at the output end of the hydraulic motor.

[0013] In one embodiment, the temperature raising system comprises: a circulating oil pump, the circulating oil pump being connected to the test container via a circulating pipeline; a heater installed in the circulation pipeline; A cooler is installed in parallel with the circulation pipeline via a branch line 1, and a seventh shut-off valve is installed on the branch line.

[0014] In one embodiment, the heating system further comprises: Fuel tank five and fuel tank six, the height of fuel tank six is ​​lower than the test container, the output end of fuel tank six is ​​connected to a pump, the height of fuel tank five is higher than the test container, the output end of the pump is connected to the input end of fuel tank five, the first output end of fuel tank five is connected to fuel tank six via branch two, and is connected to the circulation pipeline by intersection, and is installed with a third stop valve before the intersection, and a ninth stop valve after the intersection, the second output end of fuel tank five is connected to the circulation pipeline via branch three, and branch three is installed with a fourth stop valve; An air compressor is connected to the circulation pipeline via branch four, and a first stop valve is installed on branch four.

[0015] The beneficial effects of the technical solutions provided in the embodiments of the present application include: The test vessel serves as the core bearing structure, accommodating the drilling pressure loading system, the rock sample rotation drive system, and bearing the effects of the pressure control system and the heating system, realizing rock breaking tests under high temperature and high pressure environments. The pressure control system is connected to the test vessel and can pressurize, relieve and stabilize the pressure inside the vessel, simulating the confining pressure environment at different depths underground, ensuring the stability and adjustability of pressure conditions during the test. The drilling pressure loading system is fixed in the test vessel and connected to the drill bit. It can simultaneously apply force loading and displacement loading to the drill bit, simulating the dynamic mechanical behavior during the actual drilling process. The rock sample rotation drive system is fixed in the test vessel and drives the rock sample to rotate, simulating the relative motion of the drill bit when cutting rock, ensuring that the test process is closer to the actual working conditions. The heating system is connected to the test vessel and accurately controls the temperature in the test vessel by heating, cooling, filling and draining the thermal oil, simulating the high temperature environment underground and ensuring temperature uniformity and stability. This enables the device to more realistically simulate the process of PDC drill bit cutting rock under high temperature and high pressure conditions, thereby improving the accuracy of test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 It is a structural diagram of the pressure control system; Figure 2 This is a structural diagram of the bit weight loading system; Figure 3 This is a structural diagram of the rock sample rotation drive system; Figure 4 Schematic diagram of the heating system.

[0018] In the figure: 1. Test container; Pressure control system: 1a, fuel tank 1; 2a, variable displacement pump 1; 3a, drive motor 1; 4a, first filter; 5a, overflow valve 1; 6a, sixth check valve; 7a, second filter; 8a, accumulator 1; 9a, proportional pressure reducing valve; 10a, solenoid reversing valve; 11a, servo reversing valve 1; 12a, ball valve; 13a, pressure regulator; 14a, third filter; 15.1a, first check valve; 15.2a, second check valve; 15.3a, third check valve; 15.4a, fourth check valve; 15.5a, fifth check valve; 16a, supercharger; 17a, pressure needle valve 1; 18a, fuel tank 2; WOB loading system: 1b, oil tank 3; 2b, drive motor 2; 3b, variable pump 2; 4b, filter 4; 5b, relief valve 2; 6b, check valve 7; 7b, accumulator 2; 8b, filter 5; 9b, servo reversing valve 2; 10b, balancing valve 1; 11b, proportional relief valve; 12b, loading cylinder. Rock sample rotation drive system: 1c, oil tank 4; 2c, drive motor 3; 3c, variable pump 3; 4c, sixth filter; 5c, overflow valve 2; 6c, eighth check valve; 7c, seventh filter; 8c, electro-hydraulic proportional reversing valve; 9c, pressure compensator; 10c, balancing valve 2; 11c, hydraulic motor; Heating system: 1d, air compressor; 2.1d, first stop valve; 2.2d, second stop valve; 2.3d, third stop valve; 2.4d, fourth stop valve; 2.5d, fifth stop valve; 2.6d, sixth stop valve; 2.7d, seventh stop valve; 2.8d, eighth stop valve; 2.9d, ninth stop valve; 2.10d, tenth stop valve; 3.1d, pressure needle valve two; 3.2d, pressure needle valve three; 4d, oil tank five; 5.1d, eighth filter; 5.2d, ninth filter; 6d, circulating oil pump; 7d, heater; 8d, cooler; 9d, oil tank six; 10d, oil pump. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] An embodiment of the present application provides a PDC drill bit cutting tooth rock breaking test device, which can solve the technical problem that the traditional PDC drill bit cutting tooth rock breaking test device cannot truly reflect the impact of temperature and pressure on the PDC drill bit when cutting rock in an underground high temperature and high pressure environment, and the conclusions drawn from the test are easily distorted.

[0021] An embodiment of the present application provides a PDC drill bit cutting tooth rock breaking test device, which includes: a test container 1; a pressure control system, which is connected to the test container 1 and is configured to pressurize, relieve pressure and stabilize the test container 1; a drilling pressure loading system, which is arranged in the test container 1 and is used to be fixed to the drill bit, and is configured to apply force loading and displacement loading to the drill bit; a rock sample rotation drive system, which is arranged in the test container 1 and is used to be fixed to the rock sample, and is configured to drive the rock sample to rotate; a heating system, which is connected to the test container 1 and is configured to heat, cool, inject and drain the thermal oil in the test container 1.

[0022] In this embodiment, the test vessel 1 serves as the core bearing structure, accommodating the drilling pressure loading system, the rock sample rotation drive system, and bearing the functions of the pressure control system and the heating system, thereby realizing rock breaking tests under high temperature and high pressure environments. The pressure control system is connected to the test vessel 1 and can pressurize, relieve, and stabilize the interior of the vessel, simulating the confining pressure environment at different depths underground, ensuring the stability and adjustability of the pressure conditions during the test. The drilling pressure loading system is fixed in the test vessel 1 and connected to the drill bit, and can simultaneously apply force loading and displacement loading to the drill bit, simulating the dynamic mechanical behavior during actual drilling. The rock sample rotation drive system is fixed in the test vessel 1 and drives the rock sample to rotate, simulating the relative motion of the drill bit when cutting rock, ensuring that the test process is closer to actual working conditions. The heating system is connected to the test vessel 1 and accurately controls the temperature in the test vessel by heating, cooling, filling, and draining the thermal oil, simulating the high temperature environment underground and ensuring temperature uniformity and stability. This enables the device to more realistically simulate the process of PDC drill bit cutting rock under high temperature and high pressure conditions, thereby improving the accuracy of the test data.

[0023] In one embodiment, Figure 1 As shown, the pressure control system includes: an oil tank 1a, the output end of the oil tank 1a is connected to a variable pump 2a; a servo reversing valve 11a, the pressure oil inlet of the servo reversing valve 11a is connected to the output end of the variable pump 2a, and the return oil port of the servo reversing valve 11a is connected to the oil tank 1a; a supercharger 16a, the first actuator connection port of the servo reversing valve 11a is connected to the right chamber of the supercharger 16a, and its second actuator connection port is connected to the right chamber of the supercharger 16a. The connecting port is connected to the left chamber of the supercharger 16a, the left chamber of the supercharger 16a is connected to the test container 1 through the fifth one-way valve 15.5a, and the right chamber of the supercharger 16a is connected to the test container 1 through the fourth one-way valve 15.4a; the oil tank 2 18a, the oil tank 2 18a is connected to the left chamber of the supercharger 16a through the second one-way valve 15.2a, and the oil tank 2 18a is connected to the right chamber of the supercharger 16a through the third one-way valve 15.3a.

[0024] In this embodiment, oil tank 1a serves as the hydraulic oil source. Its output is connected to variable pump 2a, providing hydraulic oil with adjustable pressure. Variable pump 2a is driven by drive motor 3a. The pressure oil inlet of servo reversing valve 11a is connected to the output of variable pump 2a, and its return oil port is connected to oil tank 1a, enabling reversal and return of the hydraulic oil. The first actuator connection port of servo reversing valve 11a is connected to the right chamber of booster 16a, while its second actuator connection port is connected to the left chamber of booster 16a. This reversal controls the reciprocating motion of booster 16a. The left chamber of booster 16a is connected to fifth check valve 15. 5a is connected to the test container 1, and the right chamber is connected to the test container 1 through the fourth check valve 15.4a, realizing a two-way supply of high-pressure oil. The oil tank 2 18a replenishes oil to the left chamber of the supercharger 16a through the second check valve 15.2a, and replenishes oil to the right chamber of the supercharger 16a through the third check valve 15.3a, ensuring the oil supply when the supercharger is in continuous operation. During the pressurization process, the servo reversing valve 11a switches to the left or right position, driving the piston of the supercharger 16a to reciprocate, and the low-pressure oil is pressurized and then input into the test container 1 through the check valves (fourth check valve 15.4a / fifth check valve 15.5a), realizing pressure increase.

[0025] In one embodiment, Figure 1 As shown, the pressure control system further includes: a pressure needle valve 17a, and the oil tank 2 18a is connected to the test container 1 through the pressure needle valve 17a.

[0026] In this embodiment, the oil tank 2 18a is directly connected to the test container 1 through the pressure needle valve 1 17a, forming an independent low-pressure pressure relief channel. By adjusting the opening of the pressure needle valve 17a, the pressure in the test container 1 can be gradually and accurately released to avoid the impact caused by the instantaneous pressure relief of the high-pressure medium. During the pressure stabilization stage, by fine-tuning the pressure needle valve 17a, small pressure fluctuations in the system (such as pressure drift caused by temperature changes) can be compensated, thereby improving the pressure control accuracy.

[0027] In one embodiment, Figure 1 As shown, the pressure control system also includes: a proportional pressure reducing valve 9a, the oil inlet of the proportional pressure reducing valve 9a is connected to the output end of the variable pump 2a, and the oil unloading port of the proportional pressure reducing valve 9a is connected to the oil tank 1a; an electromagnetic reversing valve 10a, the pressure oil inlet of the electromagnetic reversing valve 10a is connected to the oil outlet of the proportional pressure reducing valve 9a, and the oil return port of the electromagnetic reversing valve 10a is connected to the oil tank 1a; a pressure stabilizer 13a, the first actuator connection port of the electromagnetic reversing valve 10a is connected to the first lower chamber interface of the pressure stabilizer 13a, the second actuator connection port of the electromagnetic reversing valve 10a is connected to the second lower chamber interface of the pressure stabilizer 13a, the first upper chamber interface of the pressure stabilizer 13a is connected to the test container 1, and the oil tank 2 18a is connected to the second upper chamber interface of the pressure stabilizer 13a via the first one-way valve 15.1a.

[0028] In this embodiment, when the pressure sensor detects that the pressure of the test container 1 is greater than the set value, the output pressure of the proportional pressure reducing valve 9a is reduced, the electromagnetic reversing valve 10a is switched to the left position (the left position is the pressure relief position), the oil pressure in the lower chamber of the pressure stabilizer 13a is reduced, the piston moves downward, the volume of the upper chamber increases, and the excess heat transfer oil in the test container 1 enters the upper chamber of the pressure stabilizer 13a, and the oil in the lower chamber flows to the oil tank 1 1a through the left position of the electromagnetic reversing valve 10a; when it is detected that the pressure of the test container 1 is less than the set value, the output pressure of the proportional pressure reducing valve 9a is increased, the electromagnetic reversing valve 10a is switched to the right position pressure replenishing position, the high-pressure oil enters the rodless side of the lower chamber of the pressure stabilizer 13a, the piston moves upward, the volume of the upper chamber is compressed, and the heat transfer oil is pressed into the test container 1, the high-temperature heat transfer oil in the oil tank 2 18a passes through the first one-way valve 15.1a, and the second upper chamber interface of the pressure stabilizer 13a (oil replenishment to prevent vacuum).

[0029] In one embodiment, Figure 1 As shown, a sixth one-way valve 6a and a second filter 7a are sequentially installed between the output end of the variable pump 2a and the servo reversing valve 11a.

[0030] In this embodiment, the sixth one-way valve 6a prevents high-pressure oil from impacting the variable pump 2a in the reverse direction, avoids hydraulic shock caused by pump reversal or pressure fluctuation, blocks backflow when the system is depressurized, and protects the pump outlet pipeline. The second filter 7a filters particulate contaminants in the hydraulic oil to ensure the cleanliness of the oil entering the servo reversing valve 11a, extend the life of the servo valve, and avoid control failure caused by valve core sticking.

[0031] In one embodiment, Figure 1 As shown, an accumulator 8a is installed between the sixth one-way valve 6a and the second filter 7a.

[0032] In this embodiment, accumulator 8a is installed in the high-pressure oil circuit between the sixth check valve 6a and the second filter 7a. It smooths out flow fluctuations at the output of variable pump 2a (such as the inherent pulsation of a plunger pump) and reduces pressure fluctuations at the inlet of servo reversing valve 11a. In the event of a sudden pump shutdown, the accumulator releases stored hydraulic energy to maintain a brief pressure supply, preventing a sudden pressure drop in test vessel 1. It also quickly replenishes the transient flow required for the operation of servo reversing valve 11a, improving the response speed of booster 16a.

[0033] In one embodiment, Figure 1 As shown, a third filter 14a is installed between the first one-way valve 15.1a, the second one-way valve 15.2a and the oil tank 2 18a.

[0034] In this embodiment, the third filter 14a is installed in the oil replenishment pipeline between the second one-way valve 15.2a and the second oil tank 18a, filtering the heat transfer oil replenished from the second oil tank 18a to the left chamber of the supercharger 16a, preventing solid particles from abrading the supercharger seal. It forms a redundant filter with the first one-way valve 15.1a to prevent contaminants from intruding when the upper chamber of the stabilizer 13a is replenished with oil.

[0035] In one embodiment, Figure 2 As shown, the drilling pressure loading system includes: an oil tank 3 1b, wherein the output end of the oil tank 3 1b is installed with a variable pump 2 3b, wherein the variable pump 2 3b is driven by a drive motor 2b; a servo reversing valve 2 9b, wherein the pressure oil inlet of the servo reversing valve 2 9b is connected to the output end of the variable pump 2 3b, and the return oil port of the servo reversing valve 2 9b is connected to the oil tank 3 1b; a loading cylinder 12b, wherein the left chamber of the loading cylinder 12b is connected to the first actuator connection port of the servo reversing valve 2 9b, and the right chamber of the loading cylinder 12b is connected to the second actuator connection port of the servo reversing valve 2 9b; a proportional relief valve 11b, wherein the proportional relief valve 11b is installed between the left chamber of the loading cylinder 12b and the first actuator connection port of the servo reversing valve 2 9b; a loading rod is fixed to the piston rod of the loading cylinder 12b, and the loading rod is used to be fixed to the rock sample.

[0036] In this embodiment, the oil tank 3 1b stores hydraulic oil, and the output end is connected to the variable pump 2 3b to provide adjustable flow and pressure. The variable pump 2 3b dynamically adjusts the output flow according to the load demand to reduce the no-load energy consumption. The pressure oil inlet of the servo reversing valve 2 9b is connected to the output end of the variable pump 2 3b, and the return oil port is directly connected to the oil tank 3 1b to form a circulation loop. Its first actuator connection port is connected to the left chamber (rodless chamber) of the loading cylinder 12b, and its second actuator connection port is connected to the right chamber (rod chamber) of the loading cylinder 12b. It receives electrical signals to accurately control the valve core opening and direction to achieve speed / position closed-loop control of the loading cylinder 12b. The proportional relief valve 11b is connected in parallel to the oil circuit of the left chamber of the loading cylinder 12b (the main oil circuit of the rodless chamber) to dynamically limit the maximum pressure of the left chamber (e.g., 0-20MPa adjustable) to prevent overload damage to the rock sample. The relief pressure can be adjusted in real time through the PID algorithm. To match the nonlinear requirements of the WOB loading curve, the loading cylinder 12b fixes the loading rod and directly contacts the rock sample to apply WOB. Oil flows into the left chamber (rodless chamber), the piston rod extends, and positive WOB is applied. Oil flows into the right chamber (rod chamber), the piston rod retracts, and unloading or resetting is performed. During the loading phase, the controller sends a WOB command (e.g., 20 kN), the servo reversing valve 2 9b switches to the left position, pressurized oil enters the left chamber of the loading cylinder 12b, and the oil in the right chamber returns to the tank. The proportional relief valve 11b limits the pressure in the left chamber according to the set value (e.g., 10 MPa for 20 kN). If the rock sample hardness suddenly changes, causing the pressure to exceed the limit, the proportional relief valve 11b opens instantaneously to release pressure and protect the system. During the pressure holding phase, the servo reversing valve 2 9b switches to the middle position, the two chambers of the loading cylinder 12b are locked, and a constant WOB is maintained. During the unloading phase, the servo reversing valve 2 9b switches to the right position, oil flows into the right chamber, pushing the piston rod to retract, and the WOB returns to zero.

[0037] Specifically, the force loading method is to control the pressure entering the loading cylinder 12b through the proportional relief valve 11b to accurately control the thrust of the loading cylinder 12b. By selecting a suitable cylinder diameter for the loading cylinder and steplessly adjusting the relief pressure of the proportional relief valve 11b, the thrust of the loading cylinder can be controlled within the required range; the displacement loading method is to accurately control the displacement of the piston rod of the loading cylinder 12b by controlling the output flow of the servo reversing valve 29b, and the displacement control accuracy can reach ±0.01mm.

[0038] In one embodiment, a displacement sensor is provided on the loading cylinder 12b to provide real-time feedback of the displacement value, compare it with the control value, and correct the output value to ensure accurate control of the displacement.

[0039] In one embodiment, a pressure sensor is installed on the end face of the loading rod of the loading cylinder 12b, and a force sensor is set at the piston rod end of the loading cylinder 12b to provide real-time feedback of the force value, compare it with the control value, and correct the output value to ensure precise control of the force.

[0040] In one embodiment, Figure 2As shown, a seventh one-way valve 6b and a fifth filter 8b are installed between the second variable pump 3b and the second servo reversing valve 9b.

[0041] In this embodiment, the seventh one-way valve 6b prevents oil from flowing back into the variable pump 2 3b when the load suddenly changes or the system is depressurized, protects the pump body from damage due to the water hammer effect, blocks reverse leakage during the pressure holding stage, and maintains the position stability of the loading cylinder 12b. The fifth filter 8b performs fine filtering on the oil entering the servo reversing valve 2 9b to prevent the valve core from getting stuck due to contamination.

[0042] In one embodiment, Figure 2 As shown, an accumulator 7b is installed between the seventh one-way valve 6b and the fifth filter 8b.

[0043] In this embodiment, the accumulator 2 7b suppresses the flow pulsation of the variable pump 2 3b, so that the pressure fluctuation at the inlet of the servo reversing valve 2 9b is ≤±0.2MPa. When the servo valve is quickly reversed, the stored hydraulic oil is released instantaneously to meet the high-speed movement requirements of the loading cylinder 12b and avoid pump source response delay.

[0044] In one embodiment, Figure 2 As shown, a relief valve 5b is installed between the pressure oil inlet and the return oil port of the servo reversing valve 9b.

[0045] In this embodiment, when the system pressure exceeds the set value, the relief valve 2 5 directly releases the pressure to the oil tank 3 1b as a safety protection to avoid failure causing system overpressure.

[0046] In one embodiment, Figure 2 As shown, a balance valve 10b is installed between the servo reversing valve 9b and the loading cylinder 12b.

[0047] In this embodiment, when the bit pressure is suddenly unloaded (such as when the rock sample breaks), the balancing valve 10b is immediately closed to prevent the piston rod of the loading cylinder 12b from falling down uncontrollably, thereby maintaining the load position.

[0048] In one embodiment, Figure 2 As shown, the oil return port of the second servo reversing valve 9b is installed with a fourth filter 4b.

[0049] In this embodiment, the fourth filter 4b is installed in the pipeline from the oil return port of the servo reversing valve 2 9b to the oil tank 3 1b to capture metal particles generated by system wear and maintain the cleanliness of the oil in the oil tank 3 1b.

[0050] In one embodiment, Figure 3As shown, the rock sample rotation drive system includes: an oil tank 14 1c, the output end of the oil tank 14 1c is connected to a variable pump 3c, wherein the variable pump 3c is driven by a drive motor 3; an electro-hydraulic proportional reversing valve 8c, the pressure oil inlet of the electro-hydraulic proportional reversing valve 8c is connected to the output end of the variable pump 3c, and the return oil port of the electro-hydraulic proportional reversing valve 8c is connected to the oil tank 14 1c; and a hydraulic motor 11c, the input end of the hydraulic motor 11c is connected to the first actuator connection port of the electro-hydraulic proportional reversing valve 8c, and the output end of the hydraulic motor 11c is connected to the second actuator connection port of the electro-hydraulic proportional reversing valve 8c.

[0051] In this embodiment, during the startup phase, the variable pump 3c is started and outputs low-pressure (e.g., 3 MPa) oil to circulate through the neutral position of the electro-hydraulic proportional reversing valve 8c. During the acceleration phase, the controller sends a speed command (e.g., 100 rpm). The electro-hydraulic proportional reversing valve 8c receives the signal and opens to a corresponding degree. The hydraulic oil drives the hydraulic motor 11c to rotate, and the built-in encoder provides real-time speed feedback to form a closed-loop control. During the steady-speed phase, when the rock sample load torque changes, the variable pump 3c automatically adjusts the output flow rate to compensate for speed deviation. During the reversing phase, the polarity of the input signal of the electro-hydraulic proportional reversing valve 8c is changed, and the inlet and outlet oil circuits of the hydraulic motor 11c are switched to achieve forward and reverse switching.

[0052] In one embodiment, Figure 3 As shown, the rock sample rotation drive system further includes: a pressure compensator 9c installed on the electro-hydraulic proportional reversing valve 8c; and a speed sensor installed on the output end of the hydraulic motor 11c.

[0053] In this embodiment, in order to ensure that the output speed of the hydraulic motor 11c is not affected by the load during its rotation, a pressure compensator 9c is provided behind the electro-hydraulic proportional reversing valve 8c to compensate for the pressure difference before and after the electro-hydraulic proportional reversing valve 8c, thereby ensuring that the electro-hydraulic proportional reversing valve 8c can accurately control the output flow rate; a speed sensor is provided on the output shaft of the hydraulic motor 11c to detect the output speed of the hydraulic motor 11c in real time, and the speed is fed back to the PLC for comparison with the control value and correction of the control given signal, thereby accurately controlling the actual output speed of the motor.

[0054] In one embodiment, Figure 3 As shown, a sixth filter 4c is installed between the electro-hydraulic proportional reversing valve 8c and the oil tank 21c.

[0055] In this embodiment, the sixth filter 4c maintains the cleanliness of the oil in the oil tank 3 1b.

[0056] In one embodiment, Figure 3 As shown, an overflow valve 5c is installed between the pressure oil inlet and the return oil port of the electro-hydraulic proportional reversing valve 8c.

[0057] In this embodiment, when the variable pump 3c fails to control and causes an abnormal increase in pressure, it takes precedence over the main system overflow valve to form a secondary protection, working in conjunction with the pressure compensator 9c to avoid pressure oscillation.

[0058] In one embodiment, Figure 3 As shown, an eighth one-way valve 6c and a seventh filter 7c are sequentially installed between the electro-hydraulic proportional reversing valve 8c and the variable pump 3c.

[0059] In this embodiment, the eighth one-way valve 6c prevents pump reversal caused by oil backflow during shutdown, and the seventh filter 7c intercepts pollutants generated by the pump source (such as seal wear particles), reducing the failure rate of the electro-hydraulic proportional reversing valve 8c.

[0060] In one embodiment, Figure 4 As shown, the heating system includes: a circulating oil pump 6d, which is connected to the test container 1 through a circulating pipeline; a heater 7d, which is installed in the circulating pipeline; a cooler 8d, which is installed in parallel with the circulating pipeline through a branch line 1, and the branch line is equipped with a seventh stop valve 2.7d.

[0061] In this embodiment, during the heating phase, the seventh stop valve 2.7d is closed and the circulating oil pump 6d is running at full speed. Heater 7d operates at full power, and the temperature rise rate of the thermal oil reaches 10℃ / min; in the constant temperature stage, heater 7d switches to PWM modulation (duty cycle 10-100%), and automatically fine-tunes the power output when the temperature fluctuates >±0.3℃; in the cooling stage, heater 7d is closed, the seventh stop valve 2.7d is opened as needed (opening degree 0-100%), and cooler 8d is put into operation with a maximum cooling rate of 5℃ / min.

[0062] In one embodiment, Figure 4 As shown, the heating system also includes: oil tank five 4d and oil tank six 9d. The height of oil tank six 9d is lower than the test container 1. The output end of oil tank six 9d is connected to the oil pump 10d. The height of oil tank five 4d is higher than the test container 1. The output end of oil pump 10d is connected to the input end of oil tank five 4d. The first output end of oil tank five 4d is connected to oil tank six 9d through branch two, and is connected to the circulation pipeline by intersection, and a third stop valve 2.3d is installed before the intersection, and a ninth stop valve 2.9d is installed after the intersection. The second output end of oil tank five 4d is connected to the circulation pipeline through branch three, and branch three is installed with a fourth stop valve 2.4d, an air compressor 1d, and the air compressor 1d is connected to the circulation pipeline through branch four, and branch four is installed with a first stop valve 2.1d.

[0063] In this embodiment, during the oil filling stage, the thermal oil comes out from the oil tank six 9d, passes through the oil pump 10d, branch three, the fourth stop valve 2.4d, the circulating oil pump 6d and the heater 7d in sequence, and enters the flow test container 1; during the oil discharge stage, the compressed air generated by the air compressor 1d enters the test container 1 through the branch four and the first stop valve 2.1d, and squeezes out the thermal oil in the test container 1. The squeezed thermal oil passes through the circulation pipeline, the intersection of branch two and the circulation pipeline, the third stop valve 2.3d is closed, the ninth stop valve 2.9d is opened, and flows back to the oil tank six 9d.

[0064] In one embodiment, Figure 4 As shown, the output end of the oil pump 10d is installed with a tenth stop valve 2.10d, and the input end thereof is installed with a ninth filter 5.2d.

[0065] In this embodiment, the tenth stop valve 2.10d is opened before the oil pump 10d is started to avoid pump blockage. It automatically closes when the system is shut down to prevent the oil in the high-level oil tank 4d from flowing back. The ninth filter 5.2d intercepts wear particles in the oil in the low-level oil tank 9d.

[0066] In one embodiment, Figure 4 As shown, the input end of the circulation pipeline is equipped with a second pressure needle valve 3.1d, and the output end is equipped with a third pressure needle valve 3.2d.

[0067] In this embodiment, the second pressure needle valve 3.1d limits the flow and maintains the pressure to maintain the suction end pressure of the circulation pump 6d to prevent cavitation, and the third pressure needle valve 3.2d controls the back pressure to maintain the working pressure of the system under high temperature conditions.

[0068] In one embodiment, Figure 4 As shown, an eighth filter 5.1d is installed before the input end of the circulating oil pump 6d.

[0069] In this embodiment, the eighth filter 5.1d is installed before the suction port of the circulating oil pump 6d to intercept wear particles in the oil in the test container 1.

[0070] In one embodiment, Figure 4 As shown, the circulation pipeline is installed with a sixth stop valve 2.6d, which is located in front of the connection point between branch three and the circulation pipeline and behind the eighth filter 5.1d. The fifth stop valve 2.5d is installed between the pressure needle valve three 3.2d and the heater 7d.

[0071] In this embodiment, when the heater 7d and the cooler 8d are damaged, the fifth stop valve 2.5d and the sixth stop valve 2.6d can promptly cut off the connection between the circulation pipeline and the test container 1.

[0072] In one embodiment, Figure 4As shown, the circulation pipeline is installed with an eighth stop valve 2.8d, and the eighth stop valve 2.8d is connected in parallel with the cooler 8d.

[0073] In this embodiment, in the cyclic heating stage, the eighth stop valve 2.8d is opened and the seventh stop valve 2.7d is closed. In the cyclic cooling stage, the eighth stop valve 2.8d is closed and the seventh stop valve 2.7d is opened, forming double protection.

[0074] In one embodiment, Figure 4 As shown, branch four is connected with the input end of the circulation pipeline to form a first connection point. Along the conveying direction of the circulation pipeline, the first connection point is located in front of the second pressure needle valve 3.1d. Branch four is connected with the output end of the circulation pipeline to form a second connection point. Along the conveying direction of the circulation pipeline, the second connection point is located behind the third pressure needle valve 3.2d. Branch four is installed with a second stop valve 2.2d, and the first connection point is located between the second stop valve 2.2d and the first stop valve 2.1d.

[0075] In this embodiment, during the cyclic heating or cooling process, the second stop valve 2.2d is closed. During the oil unloading stage, the compressed air generated by the air compressor 1d enters the test container 1 through branch four, the first stop valve 2.1d, and the pressure needle valve 2 3.1d, and squeezes out the thermal oil in the test container 1. The squeezed thermal oil passes through the circulation pipeline, the intersection of branch two and the circulation pipeline, the third stop valve 2.3d, the fifth stop valve 2.5d and the sixth stop valve 2.6d are closed, and the ninth stop valve 2.9d is opened and flows back to the oil tank six 9d.

[0076] Furthermore, the interface height between the second pressure needle valve 3.1d and the test container 1 is higher than the interface height between the third pressure needle valve 3.2d and the test container 1. Compressed air is passed into the highest point inside the test container 1, and the heat transfer oil in the high-temperature and ultra-high-pressure container is discharged through the compressed air.

[0077] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0078] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0079] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A PDC drill bit cutting tooth rock breaking test device, characterized in that: It includes: Test container (1); A pressure control system, the pressure control system being in communication with the test container (1) and configured to pressurize, relieve, and stabilize the test container (1); A weight-on-bit loading system, the weight-on-bit loading system being arranged in the test container (1), the weight-on-bit loading system being used to be fixed to the drill bit, and being configured to apply force loading and displacement loading to the drill bit; A rock sample rotation drive system, the rock sample rotation drive system being arranged in the test container (1), the rock sample rotation drive system being used to be fixed to the rock sample and being configured to drive the rock sample to rotate; A heating system is connected to the test container (1) and is configured to heat, cool, fill and drain the heat transfer oil in the test container (1).

2. The PDC drill bit cutter rock breaking test device according to claim 1, characterized in that: The pressure control system comprises: Oil tank one (1a), the output end of the oil tank one (1a) is connected to variable pump one (2a); A servo reversing valve (11a), wherein the pressure oil inlet of the servo reversing valve (11a) is connected to the output end of the variable pump (2a), and the oil return port of the servo reversing valve (11a) is connected to the oil tank (1a); A booster (16a), wherein the first actuator connection port of the servo reversing valve (11a) is connected to the right chamber of the booster (16a), and the second actuator connection port thereof is connected to the left chamber of the booster (16a), the left chamber of the booster (16a) is connected to the test container (1) via a fifth one-way valve (15.5a), and the right chamber of the booster (16a) is connected to the test container (1) via a fourth one-way valve (15.4a); Oil tank 2 (18a), the oil tank 2 (18a) is connected to the left chamber of the supercharger (16a) through a second one-way valve (15.2a), and the oil tank 2 (18a) is connected to the right chamber of the supercharger (16a) through a third one-way valve (15.3a).

3. The PDC drill bit cutter rock breaking test device according to claim 2, characterized in that: The pressure control system further comprises: Pressure needle valve 1 (17a), the oil tank 2 (18a) is connected to the test container (1) through the pressure needle valve 1 (17a).

4. The PDC drill bit cutter rock breaking test device according to claim 2, characterized in that: The pressure control system further comprises: A proportional pressure reducing valve (9a), wherein the oil inlet of the proportional pressure reducing valve (9a) is connected to the output end of the variable pump 1 (2a), and the oil discharge port of the proportional pressure reducing valve (9a) is connected to the oil tank 1 (1a); an electromagnetic reversing valve (10a), wherein the pressure oil inlet of the electromagnetic reversing valve (10a) is connected to the oil outlet of the proportional pressure reducing valve (9a), and the oil return port of the electromagnetic reversing valve (10a) is connected to the oil tank 1 (1a); A pressure regulator (13a), the first actuator connection port of the electromagnetic reversing valve (10a) is communicated with the first lower chamber interface of the pressure regulator (13a), the second actuator connection port of the electromagnetic reversing valve (10a) is communicated with the second lower chamber interface of the pressure regulator (13a), the first upper chamber interface of the pressure regulator (13a) is communicated with the test container (1), and the oil tank (18a) is communicated with the second upper chamber interface of the pressure regulator (13a) via the first one-way valve (15.1a).

5. The PDC drill bit cutter rock breaking test device according to claim 1, characterized in that: The weight-on-bit loading system comprises: Oil tank three (1b), the output end of the oil tank three (1b) is equipped with variable pump two (3b); Servo reversing valve 2 (9b), the pressure oil inlet of the servo reversing valve 2 (9b) is connected to the output end of the variable pump 2 (3b), and the return oil port of the servo reversing valve 2 (9b) is connected to the oil tank 3 (1b); A loading cylinder (12b), wherein the left chamber of the loading cylinder (12b) is in communication with the first actuator connection port of the second servo reversing valve (9b), and the right chamber of the loading cylinder (12b) is in communication with the second actuator connection port of the second servo reversing valve (9b); A proportional overflow valve (11b), the proportional overflow valve (11b) being installed between the left chamber of the loading cylinder (12b) and the first actuator connection port of the second servo reversing valve (9b); A loading rod is fixed to the piston rod of the loading cylinder (12b), and the loading rod is used to be fixed to the rock sample.

6. The PDC drill bit cutter rock breaking test device according to claim 5, characterized in that: A pressure sensor is installed on the end surface of the loading rod of the loading cylinder (12b).

7. The PDC drill bit cutter rock breaking test device according to claim 1, characterized in that: The rock sample rotation drive system comprises: Oil tank four (1c), the output end of the oil tank four (1c) is connected to variable pump three (3c); an electro-hydraulic proportional reversing valve (8c), wherein the pressure oil inlet of the electro-hydraulic proportional reversing valve (8c) is connected to the output end of the variable pump three (3c), and the oil return port of the electro-hydraulic proportional reversing valve (8c) is connected to the oil tank four (1c); A hydraulic motor (11c), wherein the input end of the hydraulic motor (11c) is communicated with the first actuator connection port of the electro-hydraulic proportional reversing valve (8c), and the output end of the hydraulic motor (11c) is communicated with the second actuator connection port of the electro-hydraulic proportional reversing valve (8c).

8. The PDC drill bit cutter rock breaking test device according to claim 7, characterized in that: The rock sample rotation drive system also includes: A pressure compensator (9c) is installed on the electro-hydraulic proportional reversing valve (8c); A rotation speed sensor is installed at the output end of the hydraulic motor (11c).

9. The PDC drill bit cutter rock breaking test device according to claim 1, characterized in that: The heating system comprises: a circulating oil pump (6d), the circulating oil pump (6d) being connected to the test container (1) via a circulating pipeline; A heater (7d), the heater (7d) being installed in the circulation pipeline; A cooler (8d), the cooler (8d) is installed in parallel with the circulation pipeline via a branch line 1, and the branch line is installed with a seventh stop valve (2.7d).

10. The PDC drill bit cutter rock breaking test device according to claim 9, characterized in that: The heating system further comprises: Oil tank five (4d) and oil tank six (9d), the height of oil tank six (9d) is lower than the test container (1), the output end of oil tank six (9d) is connected to a pump (10d), the height of oil tank five (4d) is higher than the test container (1), the output end of the pump (10d) is connected to the input end of oil tank five (4d), the first output end of oil tank five (4d) is connected to oil tank six (9d) via branch two, and is connected to the circulation pipeline at an intersection, and a third stop valve ( 2.3d), a ninth stop valve (2.9d) is installed after the intersection, the second output end of the oil tank five (4d) is connected to the circulation pipeline through the branch three, and the branch three is installed with a fourth stop valve (2.4d); An air compressor (1d), the air compressor (1d) is connected to the circulation pipeline via a branch line four, and a first stop valve (2.1d) is installed on the branch line four.

Images