Automatic rock breaking test system and rock drillability test method

Abstract

The invention provides an automatic rock breaking test system. The system comprises a base station; the rock sample clamping device is arranged on the base station, can apply confining pressure to a rock sample and can rotate around a central shaft of the rock sample clamping device; the rock sample clamping device is used for clamping rock samples, the rock breaking assembly is arranged opposite to the rock sample clamping device, the rock debris collecting device is arranged between the rock sample clamping device and the rock breaking assembly, and the rock debris collecting device comprises a collecting box used for collecting rock debris generated by the rock breaking effect and a weighing unit used for feeding back the mass of the collected rock debris; wherein the rock breaking assembly is arranged to be capable of moving relative to the base table in the first direction, and the rock sample clamping device and the rock breaking assembly are arranged to be capable of generating relative movement in the second direction. The invention also provides a rock drillability test method. By adopting the automatic rock breaking test system and test method provided by the invention, the technical problem that quantitative analysis and optimization design of cutting tooth rock breaking parameters are difficult to carry out in the prior art can be solved.

Description

Technical Field

[0001] The invention relates to the field of experimental equipment and testing technology, and in particular to an automatic rock breaking test system and a rock drillability test method. Background Art

[0002] Deep well drilling technology is an essential key technology for the exploration and development of deep oil, gas and other resources. During deep well drilling, on the one hand, the deep rock not only increases in density and hardness under the pressure of the overlying formation and the high-density drilling fluid, but also transforms from brittle to plastic-brittle or plastic, resulting in poor drillability and low drilling speed; on the other hand, the increase in temperature in the well not only makes the working conditions of the drill bit worse, shortens the life of the drill bit, and thus reduces the efficiency of rock crushing. At present, relying solely on tests under normal pressure and temperature conditions can no longer meet actual engineering needs. High-pressure and high-temperature rock drillability tests can truly reflect the crushing characteristics of deep rocks during actual drilling. Therefore, the research and development of high-pressure and high-temperature rock drillability test systems is of great significance to improving the scientific nature of drill bit selection and personalized design, and thus improving the drilling efficiency of deep wells.

[0003] Polycrystalline Diamond Compact (PDC) drill bits are the main rock-breaking tools in today's oil and gas drilling field, with the advantages of good wear resistance and high rock-breaking efficiency. As a cutting unit, the extended life of PDC wear teeth can reduce the non-drilling time of drill bit replacement and drilling, greatly improve drilling efficiency and reduce drilling costs. However, the existing technology lacks research on the cutting performance and failure time of PDC wear teeth.

[0004] Chinese patent CN114264568A discloses an alternating rock breaking test system based on laser melting and supercooled liquid jet, which includes a box, an instrument mounting table, a temperature monitoring device and an image monitoring device. When the rock sample needs to be subjected to high and low temperature alternating destruction, the laser and the nozzle are turned on to emit the laser and the nozzle sprays the supercooled liquid to perform alternating destruction on the rock sample, and after recording the temperature of the rock sample, an image of the rock sample after being destroyed is obtained. However, it is difficult to carry out quantitative analysis and optimal design of the rock breaking parameters of the pick using this system, and it is difficult to sample the weight and volume data of rock peeling. Summary of the invention

[0005] The purpose of the present invention is to provide an automatic rock breaking test system and a rock drillability test method to solve the technical problem that it is difficult to carry out quantitative analysis of rock breaking parameters of picks and their optimal design in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides an automatic rock breaking test system for rock drillability test, comprising: a base; a rock sample clamping device arranged on the base, the rock sample clamping device can apply confining pressure to the rock sample, and the rock sample clamping device can rotate around its central axis; a rock breaking assembly opposite to the rock sample clamping device, used to apply rock breaking action to an operating point on the rock sample and feedback rock breaking force; and a rock cutting collection device arranged between the rock sample clamping device and the rock breaking assembly, the rock cutting collection device comprising a collection box for collecting rock cuttings generated by the rock breaking action and a weighing unit for feedback of the mass of the collected rock cuttings; wherein the rock breaking assembly is arranged to be able to move relative to the base in a first direction to adapt to the operating point at different rock surface positions; the rock sample clamping device and the rock breaking assembly are arranged to be able to produce relative movement in a second direction to move closer to or farther away from each other.

[0007] The present invention also provides a high-low temperature cycle rock drillability test method, comprising: step 1, clamping and fixing the rock sample, applying confining pressure, and driving the rock sample to rotate around its central axis; step 2, real-time monitoring of the surface temperature of the rock sample, moving the heating element into the working position and heating the rock sample to the peak temperature; step 3, cooling the rock sample to a preset temperature recovery temperature; step 4, enclosing the working position to collect all rock cuttings to be stripped; step 5, moving the rock breaking component into the working position and performing rock breaking operations on the rock sample, monitoring the rock breaking force and the quality of the collected rock cuttings; step 6, calculating the chip specific energy based on the peak temperature, the preset temperature recovery temperature, the rock breaking force and the quality of the rock cuttings, and evaluating the rock breaking efficiency.

[0008] Compared with the prior art, the present invention has the following beneficial effects:

[0009] The automatic rock breaking test system and test method of the present invention can meet various tests such as normal temperature rock breaking, high pressure and high temperature rock breaking, and high and low temperature cycle rock breaking, as well as carry out research on different rock breaking parameters, and conduct quantitative and comparative analysis on rock breaking effects; it can realize quantitative analysis of pick rock breaking parameters and their optimal design, and provide experimental support for optimizing pick rock breaking efficiency.

[0010] Preferably, the automatic rock breaking test system also includes a temperature control device opposite to the rock sample clamping device, the temperature control device includes a heating element, a temperature recovery element and a temperature monitoring element, the temperature control device is configured to be able to move relative to the base along the first direction, and the temperature control device and the rock sample clamping device are configured to be able to produce relative movement along the second direction.

[0011] Preferably, the automatic rock breaking test system also includes a switching component, which includes a fixed part and a movable part connected to the fixed part; a sliding component is provided between the fixed part and the base; the heating element, the temperature recovery element and the rock breaking component are all connected to the movable part, and through the movement of the movable part relative to the fixed part, one of the heating element, the temperature recovery element and the rock breaking component can be moved into an operating position opposite to the operating point, and the other two can be moved out of the operating position.

[0012] Preferably, the automatic rock breaking test system also includes an angle adjustment mechanism, which includes an adjustment frame and at least three connecting arms; the heating element, the temperature recovery element and the rock breaking assembly are connected to the side of the adjustment frame facing the rock sample clamping device; one end of the at least three connecting arms is respectively hinged to the hinge point on the side of the adjustment frame facing away from the rock sample clamping device, the hinge points of the at least three connecting arms are at different positions from each other, and the other ends of the at least three connecting arms are respectively hinged to the moving part; wherein, the at least three connecting arms include at most one fixed arm, and the other connecting arms except the fixed arm are provided with a servo push rod capable of changing the length of the connecting arm.

[0013] Preferably, the fixing member includes a base, the base extends to below the adjusting frame, and a roller is provided between the adjusting frame and the base.

[0014] Preferably, the rock cuttings collection device also includes a shielding cover and a linkage assembly, and the linkage assembly includes a guide rod, a support plate, a slider, a sliding rod and a connecting plate; the shielding cover is fixedly connected to the slider, the support plate is fixedly arranged relative to the base, the slider is arranged on the support plate and can move along the length direction of the support plate, an inclined groove is opened in the slider, the sliding rod is slidably connected in the inclined groove, the two ends of the connecting plate are respectively connected to the sliding rod and the weighing unit, the weighing unit is connected to the base through the guide rod, and the guide rod can make the weighing unit move relative to the base in the vertical direction.

[0015] Preferably, the support plate is provided with a slide groove extending along its length direction, and the connecting plate passes through the slide groove and is limited by the slide groove.

[0016] Preferably, a fan is installed on the side wall of the shielding cover, and a filter screen fixedly connected to the inner wall of the shielding cover is provided at the air inlet end of the fan.

[0017] Preferably, a confining pressure chamber for accommodating the rock sample is provided in the rock sample clamping device, the confining pressure chamber has a side wall, a closed end, and an open end opposite to the closed end, the open end faces the rock breaking assembly, and the side wall can apply confining pressure to the rock sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A three-dimensional schematic diagram of an automatic rock breaking test system in an embodiment of the present invention;

[0020] Figure 2 is a three-dimensional schematic diagram of an angle adjustment mechanism in an embodiment of the present invention;

[0021] Figure 3 A three-dimensional schematic diagram of a switching assembly and a cuttings collection device in an embodiment of the present invention;

[0022] Figure 4 A front view of a switching assembly and a cuttings collection device in an embodiment of the present invention;

[0023] Figure 5 A three-dimensional schematic diagram of a sliding assembly and a cuttings collection device in an embodiment of the present invention;

[0024] Figure 6 It is a three-dimensional schematic diagram of a cuttings collection device in an embodiment of the present invention.

[0025] Among them, 1. base; 2. rock sample clamping device; 21. rock sample; 3. rock breaking assembly; 4. rock cuttings collecting device; 41. collecting box; 42. weighing unit; 43. shielding cover; 431. fan; 432. filter; 441. guide rod; 442. support plate; 443. connecting plate; 444. sliding rod; 445. slider; 446. chute; 45. cylinder; 51. heating element; 52. temperature return element; 53. temperature monitoring element; 61. first slide; 62. second slide; 71. fixed frame; 72. turntable; 73. servo motor; 74. base; 75. roller; 8. angle adjustment mechanism; 81. adjustment frame; 82. fixed arm; 83. servo push rod. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 the present invention.

[0027] like Figures 1 to 6As shown, the present invention provides an automatic rock breaking test system for rock drillability test, comprising: a base 1; a rock sample holding device 2 arranged on the base 1, the rock sample holding device 2 can rotate around its central axis, thereby driving the rock sample 21 to rotate during operation; a rock breaking assembly 3 opposite to the rock sample holding device 2, for applying a rock breaking effect to an operating point on the rock sample 21 and feeding back the rock breaking force; and a rock cuttings collecting device 4 arranged between the rock sample holding device 2 and the rock breaking assembly 3, the rock cuttings collecting device 4 comprising a collecting box 41 for collecting rock cuttings generated by the rock breaking effect and a weighing unit 42 for feeding back the mass of the collected rock cuttings.

[0028] The rock breaking assembly 3 is configured to be movable relative to the base 1 in a first direction to adapt to the operation points at different rock surface positions. The rock surface is the rock surface facing the rock breaking assembly 3 when the rock sample 21 is clamped by the rock sample clamping device 2. Figure 3 As shown, in a specific embodiment, the rock breaking assembly 3 can move horizontally relative to the rock sample 21 along the direction of the line L to align with the working point in the rock sample 21.

[0029] The rock sample holding device 2 and the rock breaking assembly 3 are configured to be able to generate relative movement along the second direction so as to move closer to or farther from each other. In a specific embodiment, when the rock breaking assembly 3 approaches the rock sample holding device 2 and penetrates the rock sample 21 to a preset depth, the rock breaking assembly 3 performs rock breaking operation on the rock sample 21; during the rock breaking process, the rock breaking assembly 3 and the rock sample holding device 2 can further move closer to or farther from each other to increase or decrease the penetration depth; after the rock breaking is completed, the rock breaking assembly 3 and the rock sample holding device 2 can be moved away from each other to facilitate subsequent operations.

[0030] In a specific embodiment, the rock breaking assembly 3 includes a three-axis force sensor, a mounting seat, and a polycrystalline diamond composite (PDC) pick. The PDC pick is fixedly mounted on the mounting seat for cutting the rock sample 21. The three-axis force sensor is fixedly connected to the mounting seat and is used to sample the forces of the PDC pick in the X-axis, Y-axis, and Z-axis during the rock breaking test. The PDC pick is used in a chipping rock breaking test system to perform a cutting rock breaking test, which can analyze the chipping efficiency and wear characteristics of the PDC pick, so as to quantitatively study the cutting performance of the PDC pick.

[0031] like Figure 2 As shown, the chip breaking test system also includes a temperature control device opposite to the rock sample clamping device 2, and the temperature control device includes a heating element 51, a temperature recovery element 52 and a temperature monitoring element 53. A common heating tool in the prior art, such as an air-methane burner, can be used as the heating element 51; a common cooling tool in the prior art, such as a liquid nitrogen refrigerator, can be used as the temperature recovery element 52; and a common temperature sensing device in the prior art, such as a temperature sensor and an infrared camera, can be used as the temperature monitoring element 53.

[0032] In a specific embodiment, an air-methane burner is aimed at the rock sample 21, and the nozzle of the flame gun sprays a flame jet toward the rock sample 21 to heat the rock sample 21. An infrared camera monitors the surface temperature of the rock sample 21 in real time and determines the peak temperature after heating. After reaching the peak temperature, heating is stopped, and a liquid nitrogen refrigerator is aimed at the rock sample 21. The nozzle of the liquid nitrogen gun sprays a low-temperature jet toward the rock sample 21 to heat the rock sample 21 to a preset temperature, and the infrared camera monitors the surface temperature of the rock sample 21 in real time.

[0033] The temperature control device is configured to be able to move along a first direction relative to the base 1 so as to adjust the position of the temperature control device to adjust and align the operating point of the rock sample 21; the temperature control device and the rock sample clamping device 2 are configured to be able to produce relative movement along a second direction so as to adjust the distance from the temperature control device to the rock sample 21, thereby regulating the peak temperature and the temperature recovery rate, and realizing rapid and accurate control of the heating and cooling of the rock sample.

[0034] like Figure 3 and Figure 4 As shown, the automatic rock breaking test system also includes a switching component, which includes a fixed part and a moving part connected to the fixed part. The heating element 51, the temperature recovery element 52 and the rock breaking component 3 are all connected to the moving part, and the movement of the moving part relative to the fixed part can move one of the heating element 51, the temperature recovery element 52 and the rock breaking component 3 into the working position opposite to the working point, and move the other two out of the working position. A sliding component is provided between the fixed part and the base 1, and the heating element 51, the temperature recovery element 52 and the rock breaking component 3 can move in the first direction and the second direction through the sliding component.

[0035] In a specific embodiment, the sliding assembly includes a first slide 61 extending in a direction perpendicular to the rock surface and a second slide 62 extending parallel to the rock surface. The fixed member includes a fixed frame 71, the fixed frame 71 is slidably connected to the first slide 61, and the fixed member moves along the first direction on the first slide 61; the second slide 62 is arranged on the base 1, the first slide 61 is slidably connected to the second slide 62, and the first slide 61 together with the fixed frame 71 moves along the second direction on the second slide 62. The first slide 61 and the second slide 62 can also be interchanged with each other. The moving member includes a turntable 72, and the servo motor 73 is electrically connected to the turntable 72 to drive the turntable 72 to rotate relative to the fixed frame 71. Through the rotation of the turntable 72, the air-methane burner, the liquid nitrogen refrigerator and the PDC pick can be synchronously and alternately moved into and out of the operating position.

[0036] Specifically, the automatic rock breaking test system also includes an angle adjustment mechanism 8, which includes an adjustment frame 81 and at least three connecting arms; wherein, the at least three connecting arms include at most one fixed arm 82, and the other connecting arms except the fixed arm 82 are provided with a servo push rod 83 capable of changing the length of the connecting arm, and the length of the fixed arm 82 is fixed.

[0037] The side of the adjustment frame 81 facing the rock sample clamping device 2 is connected to the heating element 51, the temperature return element 52 and the rock breaking assembly 3. One end of the at least three connecting arms is respectively hinged to the hinge point of the adjustment frame 81 on the side facing away from the rock sample clamping device 2. The hinge points of the at least three connecting arms are at different positions from each other, so that the position change of the adjustment frame 81 at multiple angles can be controlled by changing the length of the connecting arm during the test, thereby achieving the adjustment of the attack angle and the roll angle of the rock sample 21 during temperature control or rock breaking. The other ends of the at least three connecting arms are respectively hinged to the moving parts, so that the moving parts can drive the heating element 51, the temperature return element 52 and the rock breaking assembly 3 to move in or out of the working position.

[0038] Figure 3 A feasible implementation mode of the present invention is shown, the PDC pick is fixed on the adjusting frame 81 through a mounting seat, the three connecting arms include a fixed arm 82, the hinge points of the three connecting arms on the adjusting frame 81 are respectively located near the outer edge of the adjusting frame 81, the three hinge points are equidistant from each other, the three connecting arms are connected to the turntable 72, the connecting arms transmit the rotation of the turntable 72 to the adjusting frame 81 and the heating element 51, the temperature recovery element 52 and the rock breaking assembly 3 thereon.

[0039] like Figure 4 As shown, more specifically, the fixing member also includes a base 74, which extends below the adjustment frame 81. A roller 75 is provided between the adjustment frame 81 and the base 74 to increase the load capacity of the adjustment frame 81 and avoid displacement of the adjustment frame 81 during the test.

[0040] like Figure 5 and Figure 6 As shown, specifically, the rock cuttings collection device 4 also includes a shielding cover 43 and a linkage assembly 44, the linkage assembly 44 includes a guide rod 441, a support plate 442, a connecting plate 443, a sliding rod 444 and a slider 445; the shielding cover 43 is fixedly connected to the slider 445, the support plate 442 is fixedly arranged relative to the base 1, the slider 445 is arranged on the support plate 442 and can move along the length direction of the support plate 442, an inclined groove 446 is opened in the slider 445, the sliding rod 444 is slidably connected in the inclined groove 446, the two ends of the connecting plate 443 are respectively connected to the sliding rod 444 and the weighing unit 42, the guide rod 441 is fixedly connected to the base 1, and the weighing unit 42 is slidably connected to the guide rod 441.

[0041] In a specific embodiment, the cylinder 45 installed under the base 1 drives the weighing unit 42 to move vertically upward along the guide rod 441, and the connecting plate 443 transmits the upward movement of the load-bearing unit to the slide bar 444, so that the slide bar 444 moves upward and applies a component force including a horizontal inward direction to the inclined groove 446, so that the two sliders 445 slide close to each other on the support plate 442, so that the shielding cover 43 is closed and together with the collection box 41, it forms a closed cover body to realize the enclosure operation position, so that all the stripped rock chips enter the collection box 41 and bear the weight, without the need to manually measure the surface volume of the rock sample 21 to obtain the data of the amount of chips, and the data sampling is intuitive and accurate; in addition, the coordination of the cylinder, the inclined groove and the slider can realize the tight closure of the cover body, which can avoid the debris formed when the rock sample is stripped and splashing, and protect the safety of the personnel around the experimental site. In a preferred embodiment, the shielding cover 43 is a structure that is wide at the top and narrow at the bottom, so that the rock chips slide along the inner wall of the shielding cover 43 and fall into the collection box 41.

[0042] After the rock breaking is completed, the cylinder 45 drives the weighing unit 42 to move vertically downward along the guide rod 441, and the shielding cover 43 is separated to both sides to facilitate subsequent work such as observation and sampling.

[0043] More specifically, a slide groove extending along the length direction of the support plate 442 is provided, and the connecting plate 443 passes through the slide groove and is limited by the slide groove to prevent the slider 445 from sliding off on both sides of the support plate 442 .

[0044] In a specific embodiment, a confining pressure chamber for accommodating the rock sample 21 is provided in the rock sample clamping device 2. The confining pressure chamber has a side wall, a closed end, and an open end opposite to the closed end. The open end faces the rock breaking assembly 3. The rock sample 21 is completely wrapped by the side wall. The side wall can apply confining pressure to all cylindrical sides of the rock sample 21 to facilitate rock breaking tests under high pressure conditions.

[0045] like Figure 6 As shown, in a specific embodiment, a fan 431 is installed on the side wall of the shielding cover 43, and the fan 431 draws air from the cover body to assist in dust reduction inside the cover body. A filter 432 fixedly connected to the inner wall of the shielding cover 43 is provided at the air inlet end of the fan 431, and the dust in the cover body will be intercepted by the filter 432 and finally slide along the inner wall of the cover body into the collection box 41.

[0046] The automatic rock breaking test system of the present invention can meet various tests such as normal temperature rock breaking, high pressure and high temperature rock breaking, and high and low temperature cycle rock breaking, and can carry out research on different rock breaking parameters, and perform quantitative and comparative analysis on rock breaking effects; it can realize quantitative analysis of pick rock breaking parameters and their optimal design, and provide experimental support for optimizing pick rock breaking efficiency.

[0047] The present invention also provides a rock drillability test method, comprising:

[0048] Step 1, clamping and fixing the rock sample, applying confining pressure, and driving the rock sample to rotate around its central axis;

[0049] Step 2: monitor the surface temperature of the rock sample in real time, move the heating element into the operating position and heat the rock sample to the peak temperature;

[0050] Step 3, cooling the rock sample to a preset temperature;

[0051] Step 4, fence the work area to collect all the rock cuttings to be stripped;

[0052] Step 5, moving the rock breaking assembly into the operating position and breaking the rock sample, monitoring the rock breaking force and the quality of the collected rock cuttings;

[0053] Step 6, calculating the chip specific energy according to the confining pressure value, peak temperature, preset reheating temperature, rock breaking force and rock cutting mass, and evaluating the rock breaking efficiency.

[0054] In step 3, the temperature recovery element can be moved into the working position to cool the rock sample or placed naturally to wait for temperature recovery. Before executing step 6, steps 2 to 5 can be repeated multiple times to analyze the influence of high and low temperature cycle temperature on rock breaking effect.

[0055] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0056] The above description of various embodiments of the present invention is provided to those skilled in the art for the purpose of description. It is not intended to be exhaustive or to limit the present invention to a single disclosed embodiment. As mentioned above, various substitutions and variations of the present invention will be apparent to those skilled in the art to which the above-mentioned technology belongs. Therefore, although some alternative embodiments have been specifically discussed, other embodiments will be apparent, or those skilled in the art will be relatively easy to derive. The present invention is intended to include all substitutions, modifications and variations of the present invention discussed herein, as well as other embodiments falling within the spirit and scope of the above-mentioned application.

[0057] Although the present invention has been described through embodiments, those skilled in the art will appreciate that there are many modifications and variations of the present invention without departing from the spirit of the present invention. It is intended that the appended claims include such modifications and variations without departing from the spirit of the present invention.

Claims

1. Automatic rock breaking test system, used for rock drillability test, characterized by: include: abutment; A rock sample holding device disposed on the base, the rock sample holding device being capable of applying confining pressure to the rock sample and being capable of rotating around its central axis; A rock breaking assembly opposite to the rock sample clamping device is used to apply a rock breaking effect to an operating point on the rock sample and to feed back the rock breaking force; and a rock-cutting collection device disposed between the rock sample holding device and the rock-breaking assembly, the rock-cutting collection device comprising a collection box for collecting rock-cuttings generated by the rock-breaking action and a weighing unit for feeding back the mass of the collected rock-cuttings; The rock breaking assembly is configured to be movable relative to the base in a first direction to adapt to the working point at different rock surface positions; the rock sample clamping device and the rock breaking assembly are configured to be able to produce relative movement in a second direction to move closer to or farther away from each other.

2. The chip breaking test system according to claim 1, characterized in that: It also includes a temperature control device opposite to the rock sample clamping device, the temperature control device includes a heating element, a temperature return element and a temperature monitoring element, the temperature control device is configured to be able to move relative to the base along the first direction, and the temperature control device and the rock sample clamping device are configured to be able to produce relative movement along the second direction.

3. The automatic rock breaking test system according to claim 2, characterized in that: It also includes a switching component, which includes a fixed part and a movable part connected to the fixed part; a sliding component is provided between the fixed part and the base; the heating element, the temperature recovery element and the rock breaking component are all connected to the movable part, and through the movement of the movable part relative to the fixed part, one of the heating element, the temperature recovery element and the rock breaking component can be moved into an operating position opposite to the operating point, and the other two can be moved out of the operating position.

4. The automatic rock breaking test system according to claim 2 or 3, characterized in that: It also includes an angle adjustment mechanism, which includes an adjustment frame and at least three connecting arms; the side of the adjustment frame facing the rock sample clamping device is connected to the heating element, the temperature recovery element and the rock breaking assembly; one end of the at least three connecting arms is respectively hinged to the hinge point on the side of the adjustment frame facing away from the rock sample clamping device, the hinge points of the at least three connecting arms are at different positions from each other, and the other ends of the at least three connecting arms are respectively hinged to the moving part; wherein, the at least three connecting arms include at most one fixed arm, and the other connecting arms except the fixed arm are provided with a servo push rod capable of changing the length of the connecting arm.

5. The automatic rock breaking test system according to claim 4, characterized in that: The fixing member comprises a base, the base extends to below the adjusting frame, and a roller is arranged between the adjusting frame and the base.

6. The automatic rock breaking test system according to claim 1, characterized in that: The rock cuttings collection device also includes a shielding cover and a linkage assembly, and the linkage assembly includes a guide rod, a support plate, a slider, a sliding rod and a connecting plate; the shielding cover is fixedly connected to the slider, the support plate is fixedly arranged relative to the base, the slider is arranged on the support plate and can move along the length direction of the support plate, an inclined groove is opened in the slider, the sliding rod is slidably connected in the inclined groove, and the two ends of the connecting plate are respectively connected to the sliding rod and the weighing unit, and the weighing unit is connected to the base through the guide rod, and the guide rod can make the weighing unit move relative to the base in the vertical direction.

7. The automatic rock breaking test system according to claim 6, characterized in that: The support plate is provided with a slide groove extending along the length direction thereof, and the connecting plate passes through the slide groove and is limited by the slide groove.

8. The automatic rock breaking test system according to claim 6, characterized in that: A fan is installed on the side wall of the shielding cover, and a filter screen fixedly connected to the inner wall of the shielding cover is provided at the air inlet end of the fan.

9. The automatic rock breaking test system according to claim 1, characterized in that: The rock sample holding device is provided with a confining pressure chamber for accommodating the rock sample. The confining pressure chamber has a side wall, a closed end, and an open end opposite to the closed end. The open end faces the rock breaking assembly. The side wall can apply confining pressure to the rock sample.

10. Rock drillability test methods, including: Step 1, clamping and fixing the rock sample, applying confining pressure, and driving the rock sample to rotate around its central axis; Step 2: monitor the surface temperature of the rock sample in real time, move the heating element into the operating position and heat the rock sample to the peak temperature; Step 3, cooling the rock sample to a preset temperature; Step 4, fence the work area to collect all the rock cuttings to be stripped; Step 5, moving the rock breaking assembly into the operating position and breaking the rock sample, monitoring the rock breaking force and the quality of the collected rock cuttings; Step 6, calculating the chip specific energy according to the peak temperature, the preset temperature recovery temperature, the rock breaking force and the rock breaking mass, and evaluating the rock breaking efficiency.

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