CN112922551A - Rock mass coring bit under high ground stress - Google Patents

Abstract

The invention provides a rock mass coring bit under high ground stress, which at least comprises an outer cylinder assembly, an inner cylinder assembly and a core gripper assembly, wherein the inner cylinder assembly and the core gripper assembly are arranged in an inner cavity of the outer cylinder assembly, the inner cylinder assembly at least comprises a core inner tube and a core filling part, the core filling part is connected with the open end of the core inner tube with a one-way opening in a mode that the core filling part is connected with one end of the core inner tube to form a sealed cavity of the core inner tube, the same open end of the core inner tube is also connected with the core gripper assembly, the core gripper assembly at least comprises a hoop connecting seat, a hoop limiting body and a hoop, the hoop connecting seat and the core filling part are both arranged at the open end of the core inner tube with the one-way opening, the hoop can be translated along the axial direction of the hoop limiting body to change the size of a hollow ring diameter limited by the hoop inner ring, and then the clamp can fix the position of the core in the lifting process of the inner barrel assembly.

Description

Rock mass coring bit under high ground stress

Technical Field

The invention relates to the technical field of rock mass drilling and sampling, in particular to a rock mass coring bit under high ground stress.

Background

In recent years, the demand for energy has become increasingly dependent on the development of life and production of people, and among them, gas resources have become the blood of social development. However, from the current oil and gas resource exploitation situation, the gas resources on the earth surface and the earth shallow layer, which can be exploited by people, are nearly exhausted, and in order to solve the problem of shortage of oil and gas resources available for exploitation by people in the future, energy exploration and exploitation need to be performed on a deep region of a complex stratum with a large number of geological reservoirs. The high ground stress is the fundamental destructive power which causes the deformation of various underground or open-air geotechnical excavation engineering such as mining, water conservancy and hydropower, civil engineering, military affairs, railway roads and the like. Therefore, in order to master the special underground geological conditions and directly obtain real and reliable stratum related data, a great amount of coring work is required in the exploration stages of oil and gas reservoir development and deep-buried underground engineering. The rock in the high ground stress environment has large initial pressure, when the core is upwards transported in the coring process, the core cake phenomenon can be caused due to sudden reduction of the surrounding pressure, so that great uncertain factors are brought to subsequent core analysis work, and in order to prepare enough accurate and sufficient early-stage data for subsequent energy exploration and exploitation, a core sample drill bit which can effectively eliminate the acting force of the high ground stress on the drilled core and can well store and take out the core is needed, so that the core sample which is completely stored and can be conveniently and effectively detected can be obtained.

Chinese patent CN104314497A discloses a core sealing device applied to a hydraulic pressurizing type coring tool, which comprises a safety joint, a release device, an outer cylinder component, an inner cylinder component and a core claw component, wherein the safety joint is in a conical shape with a hollow bottom and a hollow top, the upper part is big, the lower part is small, the middle part of the safety joint is in threaded connection with the outer cylinder component, and the lower part is in threaded connection with the release device; the inner cylinder assembly is arranged below the releasing device, the core claw assembly is arranged below the inner cylinder assembly, and the releasing device, the inner cylinder assembly and the core claw assembly are located in the outer cylinder assembly. The invention can reasonably utilize the hydraulic pressure of the drilling fluid to realize the purpose of completely wrapping the broken rock core. When the plastic deformation of the core claw assembly reaches a certain degree, drilling fluid is discharged from a gap between the core sealing sleeve and the connecting sleeve, so that the core is not excessively compressed, and the integrity of the core is ensured. Finally, the purpose that the core sealing sleeve completely wraps the broken core is achieved. And the coring yield in soft and broken stratum is ensured. Although this patent is provided with the rock core claw of dead weight formula, its single rock core claw can not fix the rock core in rock core accommodation chamber effectively, especially when the rock core breaks, the cross-section size of rock core can have the change, breaks away from and goes out from the passageway of coring easily, in addition, the device can only utilize hydraulic pressure self gravity change and its accommodation chamber to inject the settlement pressure to improve the validity that the rock core was preserved alone, lacks the rock core that can be according to the controllable rock core of holding the chamber pressure size of adjusting of actual pressure and ground stress change and takes accuse pressure structure.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a rock mass coring bit under high ground stress. According to the invention, by arranging the core holding and storing structure capable of effectively eliminating high ground stress and the core claw structure capable of fixedly intercepting the core, the core can be separated from the rock body through the core claw structure with double-clamping limitation under the condition of ensuring the completeness of the core, and the core is effectively stored in the core holding cavity, so that the acquisition of a perfect core sample is realized. By the drill bit and the rock mass coring method under high ground stress by using the drill bit, the recovery ratio of stress-preserving coring is improved, the occurrence of core caking phenomenon is prevented, and the reliability of subsequent core analysis data is improved. The rock core bit under the high ground stress comprises a bit body, wherein an inner barrel assembly used for keeping and taking out a rock core is arranged in a radial inner cavity of a drill rod of the bit body, and is characterized in that a hydraulic assembly is arranged on the inner barrel assembly in a mode of monitoring and/or adjusting pressure applied to a rock core sample, the hydraulic assembly at least comprises a monitoring sensing module and a hydraulic adjusting module, wherein the hydraulic adjusting module can adjustably change the pressure applied to the rock core sample by comparing pre-collected ground stress data with real-time pressure applied to the rock core sample monitored by the monitoring sensing module, so that at least part of axial sections of the rock core contained in the inner barrel assembly are subjected to radial pressure corresponding to the pre-collected ground stress data. The coring mechanism can adjust the radial pressure applied to the surface of the core by the mechanism in real time according to the pressure change borne by the core during the core drilling and taking processes, so that the core can be always subjected to the radial pressure corresponding to the pre-collected ground stress data during the whole coring operation process.

According to a preferred embodiment, the inner cylinder assembly at least comprises a hydraulic pressurization part and a core pressurization part, wherein the hydraulic pressurization part changes the pressure applied by the core pressurization part to the adopted core according to the comparison result of the hydraulic adjustment module; the monitoring sensing module is arranged on the surface of a chamber where the rock core pressurizing part is in contact with the collected rock core. The invention proposes that the hydraulic pressurisation section is responsive to a command for completion of the drill bit drilling to initiate a radial pressurisation operation. Even pressure is exerted to the whole side chamber wall in the rock core holding chamber of rock core pressurization portion through hydraulic pressure pressurization portion for the rock core surface can receive the equal and even pressure of rock core crustal stress size in the rock mass in circumference. The core compression device has the advantages that the core compression part with the inner cavity and the outer cavity which are not communicated with each other is arranged, so that when the core is stored in the inner cavity, high-pressure fluid is input into the outer cavity which wraps the inner cavity to apply the crustal stress on the core wrapped in the wear-resistant rubber die sleeve, which is equivalent to the crustal stress on the core in an initial stratum, and further stress-preserving coring is performed in a high-stress deep stratum; in addition, the core entering the core accommodating cavity is wrapped in the rubber mold, so that the appearance distribution of the in-situ stratum of the core can be completely reserved.

According to a preferred embodiment, the core pressing section comprises: the core containing part is detachably connected with the core inner tube to form a sealed high-pressure fluid cavity, and the core containing part also comprises a core containing cavity for containing a core sample; in a first stage that at least part of axial section of the drilled core sample enters the core accommodating cavity, the monitoring and sensing module monitors the radial pressure of the core sample in the core accommodating cavity in real time and transmits the radial pressure to the hydraulic adjusting module for comparative analysis, so that the hydraulic pressurizing part completes a first pressurizing operation of providing radial pressure corresponding to pre-collected ground stress data to at least part of axial section of the drilled core in a radial direction in a mode of injecting hydraulic oil into the high-pressure fluid cavity of the core pressurizing part according to a comparison result. This application is through repacking inner tube subassembly front end for detachable component, owing to adopt the characteristics of rope coring, need not dig into, only need to mention the coring pipe from the well with the steel wire, after the coring pipe is mentioned from the well, ground personnel can be fast with the detachable device replacement of coring pipe front end, greatly accelerate the speed that the rock core bored and get, and pour into high-pressure fluid into in advance subaerial after, if discover high-pressure fluid's sudden pressure drop, can judge that high-pressure fluid produces reveals, can judge before the coring pipe under whether can take place to reveal, if take place to reveal, ground personnel can change detachable device fast, can greatly improve the sealing performance of coring pipe front end.

According to a preferred embodiment, under the condition that the drill bit body finishes core drilling and the hydraulic pressurization part finishes the first pressurization operation for core drilling, the inner cylinder assembly moves along with the core transfer system at the second stage of lifting the inner cylinder assembly on the core transfer system arranged at the axial upper end of the core pressurization part, so that the core gripper assembly arranged at the axial lower end of the inner cylinder assembly cuts off the connection between the core and the rock body in a mode of limiting the separation of the core from the inner cylinder assembly.

According to a preferred embodiment, in a third stage that the core gripper assembly finishes the truncation and the limiting of the core sample after lifting along with the inner cylinder assembly and the core transfer system further lifts the inner cylinder assembly, the hydraulic adjusting module performs comparative analysis on real-time radial pressure applied to the core sample in the lifting process monitored by the monitoring and sensing module and pre-collected ground stress data, and the hydraulic adjusting module controls the hydraulic pressurizing part to inject hydraulic oil into the high-pressure fluid chamber of the core pressurizing part according to the real-time pressure data comparative result according to the change of the radial pressure applied to the core sample in the lifting process monitored by the monitoring and sensing module, so that the real-time radial pressure applied to the core sample corresponds to the pre-collected ground stress. The core pressure-bearing device has the advantages that the magnitude of the protective stress provided by the static high-pressure fluid can be kept in a relatively stable state all the time in the drill lifting process, so that the service life of the core pressure-bearing part is relatively long, the range of the protective stress which can be applied is relatively wide, the phenomenon of core caking can be effectively prevented, and the recovery ratio of the protective stress coring is remarkably improved.

According to a preferred embodiment, the core gripper assembly comprises a clamp connecting seat, a clamp limiting body, a clamp and a core clamping piece, the clamp moves downwards in the clamp limiting body due to contact friction with the core at the initial stage of lifting the core carried by the inner barrel assembly, so that the clamp is radially compressed from the clamp limiting body to reduce the inner ring diameter, the friction force between the clamp and the contact surface of the core is increased, and the connection between the core and a rock body is broken along with the lifting operation. The drill core lifting device has the advantages that the clamp can be used for carrying out limiting support on the drill core after the coring operation is completed, and meanwhile, the coring assembly can be used for driving the lifting operation of the drill core to enable the drill core to be separated from a rock body in a fracture mode, so that the drill core which is limited and fixed by the clamp can be taken out from a drilled hole along with the inner cylinder assembly. In addition, the setting of rock core fastener can make the fastener body of rod carry out the secondary to the rock core fixed with support, and especially rock core fastener body of rod front end can support the relative fixation between rock core and the coring device in the rock core surface further to guarantee aslope, avoids it to drop the roll-off from the coring device.

According to a preferred embodiment, in the second stage of lifting the inner barrel assembly, the clamp slides downwards relative to the clamp limiting body, and the core clamping piece adjusts the working position of the core clamping piece according to the movement of the clamp, wherein in the first stage of rock mass coring, the core clamping piece is limited in the limiting groove of the clamp limiting body by the clamp; when the second phase of rock mass coring, the rock core clamping piece breaks away from the limit of the clamp to the rock core clamping piece along with the movement of the clamp, so that the rock core clamping piece supports the clamping position of the rock core according to the mode that part of the rod body of the rock core clamping piece moves out of the limiting groove.

According to a preferred embodiment, the core gripper assembly comprises a clamp connecting seat, a clamp limiting body, a clamp and a core clamping piece, the clamp moves downwards in the clamp limiting body due to contact friction with the core at the initial stage of lifting the core carried by the inner barrel assembly, so that the clamp is radially compressed from the clamp limiting body to reduce the inner ring diameter, the friction force between the clamp and the contact surface of the core is increased, and the connection between the core and a rock body is broken along with the lifting operation.

According to a preferred embodiment, the drill bit body at least comprises a drill rod with an axial inner chamber and a drill bit end connected with one end of the drill rod, wherein a plurality of drill bit teeth are arranged on the end surface of the end, far away from the end of the drill rod, of the drill bit end, wherein the plurality of drill bit teeth are arranged into first working teeth and second working teeth in a manner capable of forming two different annular drilling working surfaces, and the first working teeth and the second working teeth are circumferentially staggered on the end surface of the drill bit end.

The application also provides a use method of the rock mass coring bit under high ground stress, wherein an inner cylinder assembly capable of keeping and taking out a rock core is installed in a radial inner cavity of a drill rod of the outer cylinder assembly, and a rock core pressurizing part is arranged on the inner cylinder assembly in a manner of providing radial pressure for a rock core sample entering the inner cavity of the drill rod; the inner cylinder assembly further comprises a hydraulic pressurization part which can provide radial pressure corresponding to the pre-collected ground stress data to the rock core in the rock core pressurization part according to the pre-collected ground stress data.

Drawings

FIG. 1 is a hydraulic control flow diagram of a preferred embodiment of a rock mass coring bit under high ground stress of the present invention;

FIG. 2 is a schematic structural view of a preferred embodiment of a rock mass coring bit under high ground stress according to the present invention;

FIG. 3 is a schematic partial structural view of a preferred embodiment of a core gripper assembly of the rock core bit of the present invention at high ground stress;

FIG. 4 is a schematic structural view of a core gripper assembly of the rock core bit under high ground stress of the invention when the rock core bit is lifted;

FIG. 5 is a schematic structural view of the front end of the bit body of the preferred embodiment of the rock core bit under high ground stress of the present invention;

FIG. 6 is a schematic structural view of a core receiver of the rock coring bit of the present invention at high ground stress;

fig. 7 is a schematic view showing the expansion of the wall of the core-receiving chamber of the rock core-coring bit of the present invention under high ground stress.

List of reference numerals

1: the bit body 2: an inner cylinder component 3: core gripper assembly

4: core transfer system 11: the drill stem 12: drill bit

21: hydraulic pressure increasing unit 22: core pressing portion 31: clamp connecting seat

32: the clamp stopper 33: the clamp band 34: core fastener

5: the hydraulic assembly 51: the monitoring sensing module 52: hydraulic adjusting module

53: the processing module 121: bit teeth 122: first working tooth

123: second working tooth 124: flow guide groove 125: outer trough

126: inner groove 211: a liquid storage bin 212: conveying pipeline

213: the driving section 211: a liquid storage bin 212: conveying pipeline

213: the driving section 214: power supply 221: core inner tube

222: core receiver 223: high-pressure fluid chamber 224: core holding cavity

225: the limiting module 321: the limiting groove 322: shaft lever

323: the torsion spring 341: the support rod 342: limiting block

511: temperature sensing unit 512: pressure sensing unit 513: depth sensing unit

521: solenoid valve 522: electromagnetic valve

Detailed Description

The drill bit is used for rock drilling sampling exploration under high ground stress conditions. The drill comprises a drill body 1, an inner cylinder assembly 2, a core gripper assembly 3 and a core transfer system 4. The inner cylinder assembly 2 and the core gripper assembly 3 are arranged in an inner cavity of the drill bit main body 1, and one end, far away from the core transfer system 4, of the inner cylinder assembly 2 is connected with the core gripper assembly 3. The core transfer system 4 can pull the inner barrel assembly 2 and the drill bit body 1 out, so that the inner barrel assembly 2 in the stratum can be transferred to the ground after rock drilling sampling exploration.

The core transfer system 4, the inner barrel assembly 2 and the core gripper assembly 3 are all arranged in a radial inner chamber of a drill rod 12 of the drill bit body 1. The core transfer system 4, the inner barrel assembly 2 and the core gripper assembly 3, which are arranged in the inner chamber of the drill rod 12, are connected in sequence in the axial direction in such a way that they are parallel to and preferably collinear with the axis of the drill rod 12.

The core transfer system 4 is arranged in an inner cavity of the drill rod 12 close to the ground, so that the core transfer system 4 can control the inner cylinder assembly 2 and the core gripper assembly 3 which are connected with each other to move up and down together in an axial inner cavity of the drill rod 12.

The inner barrel assembly 2 includes a core inner tube 221 and a core receiver 222. The core receiver 222 is sleeved into the core inner tube 221 via an axial opening of the core inner tube 221. The axial lower end of the core receptacle 222 and the open end of the core inner tube 221 having the unidirectional tube cavity opening are connected to each other in a form-fitting manner, so that the core receptacle 222 forms a sealed cavity of the core inner tube 221 by being in sealed connection with the core inner tube 221.

The core accommodating part 222 and the core inner tube 221 are sleeved with each other to form a high-pressure fluid chamber 223 with an inverted U-shaped axial section, wherein the high-pressure fluid chamber 223 can apply pressure to the wall of the core accommodating cavity 224, and the inner side walls of the high-pressure fluid chamber 223 in the radial direction and the axial direction are formed by the side wall and the axial wall of the core accommodating cavity 224. The radially outward outer wall and the axially upward outer wall of the high-pressure fluid chamber 223 are formed by the inner side wall and the axially upward top interior of the inner chamber of the core inner tube 221. The lower axial end of the inverted U is sealed by the junction of the core inner tube 221 and the core receiver 222. The closed chamber defined by the inner chamber wall of the core inner tube 221, the core receiver 222 and the core receiver 224 forms a high pressure fluid chamber 223 capable of containing pressurized fluid. Wherein the inner sidewall of the high pressure fluid chamber 223 is formed of a flexible material and the outer sidewall thereof is formed of a rigid material. According to the invention, the high-pressure fluid cavity 223 is a closed liquid storage cavity which is formed by combining the inner cavity of the core inner tube 221 and the core containing part 222 with the core containing cavity 224 and has a flexible cavity wall and a rigid cavity wall, so that when the hydraulic pressure in the high-pressure fluid cavity 223 is increased, the acting force of hydraulic oil in the cavity on the cavity wall is mainly converged on the radial inner cavity wall capable of deforming. And the radial inner cavity wall of the high-pressure fluid cavity 223 is the side cavity wall of the core accommodating cavity 224, so that the core in the core accommodating cavity 224 can be subjected to pressure uniformly distributed in the circumferential direction. Thereby effectively improving the uniformity of the pressure borne by the rock core.

The high-pressure fluid chamber 223 is communicated with the hydraulic pressurizing part 21 through a delivery pipe 212 penetrating the upper top of the chamber at the axial upper end thereof. The hydraulic pressurizing part 21 is arranged above the axis of the core inner tube 221 and connected with the upper end of the tube body of the core inner tube 221. After the core drilled by the drill bit completely enters the core accommodating cavity 224, a certain amount of hydraulic oil is injected into the high-pressure fluid cavity 223 by the hydraulic pressurizing part 21 according to the magnitude of the pre-collected ground stress, the expansion pressure applied to the cavity wall of the high-pressure fluid cavity 223 is increased along with the increase of the hydraulic oil in the cavity of the high-pressure fluid cavity 223, so that the acting force applied to the side cavity wall of the core accommodating cavity 224 is gradually increased, and the pressure applied to the main radial surface of the adopted core is gradually increased to the magnitude of the ground stress applied to the core in the rock mass. And because the whole side cavity wall of the core accommodating cavity 224 forms the cavity wall of the radial inner side of the high-pressure fluid cavity 223, when the pressure in the cavity of the high-pressure fluid cavity 223 increases, all cavity walls of the high-pressure fluid cavity 223 can be subjected to the acting force from inside to outside with the same magnitude, so that the pressure acting on the whole side cavity wall of the core accommodating cavity 224 is equal everywhere, and the surface of the core can be subjected to the pressure with uniform magnitude in the circumferential direction.

The open end of the core inner tube 221 and the axial upper end of the core gripper assembly 3 are connected in a form-fitting manner. As shown in fig. 4, the core gripper assembly 3 may include a clamp connection seat 31, a clamp stopper 32, and a clamp 33. The axially upper end of the clamp connection seat 31 and the open end of the core inner tube 221 are connected to each other in a form-fitting manner. One end of the clamp connecting seat 31, which is far away from the core inner tube 221, is connected with a clamp limiting body 32 capable of installing a clamp 33, and the clamp 33 is arranged in an axial inner diameter channel of the clamp limiting body 32. The clamp 33 arranged coaxially with the clamp limiting body 32 can translate along the axial direction of the clamp limiting body 32 to change the size of the hollow ring diameter limited by the clamp 33, so that the friction between the clamp 33 and the surface of the core can be adjusted, and the position of the core in the lifting process of the inner barrel assembly 2 can be fixed by the clamp 33.

After a core drilled by the hollow drill enters the inner cavity of the drill rod from the opening at the axial lower end of the core, the core column passes through the through hole-shaped channel in the core gripper assembly 3 and then enters the core accommodating cavity 224. The surface of the core pillar can contact and rub with the annular inner wall of the clamp 33 to drive the clamp 33 to move upwards along the axis of the core limiting body 32. The diameter of the through port formed by the mutual connection of the axial upper end of the core limiting body 32 and the axial lower end of the core connecting seat 31 is smaller than the diameter of the axial upper end of the clamp 33, so that the clamp 33 is limited to be separated from the limiting chamber of the core limiting body 32, and the clamp 33 only moves up and down in the limiting chamber of the core limiting body 32. Under the condition of accomplishing coring operation and lifting core inner tube 221, clamp 33 takes place for the downward removal of clamp spacing body 32's axial along with the operation that rises, make the interior aperture that has the limited of lateral wall open-ended clamp 33 reduce, thereby with the frictional force increase between the rock core contact surface, the rock core reduces along with the interior aperture of clamp 33 gradually, make rock core and rock core claw subassembly 3, the unchangeable spacing connection of relative position has been formed between the inner tube subassembly 2, and then in the operation process that inner tube subassembly 2 continues upwards to promote, the cracked external force of pulling between rock core and the rock mass increases gradually, finally make rock core and rock mass take place to separate.

As shown in fig. 3, a core clamper 34 is further arranged in the hoop limiting body 32. Offer the vallecular cavity that can set up the body of rod of rock core fastener 34 on the inner wall of clamp spacing body 32, when installing rock core fastener 34 in the vallecular cavity of clamp spacing body 32, the one end that the body of rod of rock core fastener 34 is close to drill bit end 12 is connected with the vallecular cavity wall rotation of clamp spacing body 32. The clamp limiting body 32 is provided with a plurality of core clamps 34 along the inner circumferential surface, the connecting positions of the core clamps 34 and the clamp limiting body 32 are provided with return springs, so that when the clamp 33 moves relatively along with a core in the lifting process and limits the core clamps 34, the core clamps 34 rotate relatively around the connecting positions of the inner wall grooves of the clamp limiting body 32, the rod body of the core clamps 34 can rotate to slide out the inner wall grooves under the action of the return springs, one end, far away from the core clamps 34, connected with the clamp limiting body 32 is embedded on the surface of the core, and the relative fixation of the core and the core claw assembly 3 is further guaranteed. Can carry out spacing support to the rock core after accomplishing the coring operation through the clamp that sets up and can utilize the operation of lifting that the coring subassembly drove the rock core simultaneously to make rock core and rock mass break off to make and follow the interior section of thick bamboo subassembly and extract from drilling by the spacing fixed rock core of clamp. In addition, make the fastener body of rod can carry out the secondary to the rock core through setting up rock core fastener 34 and fix and support, especially rock core fastener body of rod front end can insert the relative fixation between further assurance rock core and the coring device in the rock core surface aslope, avoids it to drop the roll-off from the coring device.

Example 1

As shown in fig. 2, the inner barrel assembly 2 is further provided with a hydraulic assembly 5, and the hydraulic assembly 5 includes a monitoring sensing module 51 and a hydraulic pressure adjusting module 52. The monitoring sensor module 51 is optionally mounted to the core pressurization portion 22 in a manner that enables monitoring of the environmental parameters of the core. The hydraulic adjusting module 52 is arranged at the hydraulic pressurizing part 21, so that the hydraulic adjusting module 52 can adjust the acting force of the hydraulic pressurizing part 21 on the core pressurizing part 22 according to the feedback signal sent by the monitoring sensing module 51. As shown in fig. 1, the monitoring sensing module 51 includes a temperature sensing unit 511, a pressure sensing unit 512, and a depth sensing unit 513. The temperature sensing unit 511 and the pressure sensing unit 512 are provided on the surface of the core pressing portion 22 that contacts the core sample so as to monitor the temperature and the pressure of the core sample being sampled. A depth sensing unit 513 is optionally provided on the inner barrel assembly 2. Preferably, the hydraulic assembly 5 further comprises a processing module 53 capable of processing the data collected by the monitoring and sensing module 51 and outputting the processed result to the hydraulic pressure adjusting module 52. The processing module 53 is in signal connection with the monitoring sensing module 51 and the hydraulic pressure adjusting module 52. The processing module 53 can regulate and control the amount and the flow direction of the hydraulic oil driven by the hydraulic pressurization part 21 according to the real-time temperature, the height and the pressure parameters of the environment where the core sample is located, so as to regulate the pressure applied to the core pressurization part 22. Preferably, the hydraulic regulation module 52 includes a control switch 521 and a solenoid valve 522. The control switch 521 is connected to the driving unit 213 to control whether or not the driving unit 213 of the hydraulic booster 21 constitutes a complete electric circuit. The solenoid valve 522 is provided in the conveyance pipe 212 of the hydraulic pressurization unit 21 so as to restrict the flow of the hydraulic oil between the hydraulic pressurization unit 21 and the core pressurization unit 22. Each of the electric power units of the hydraulic unit 5 and the driving unit 213 of the hydraulic booster 21 are electrically connected to a power supply.

Preferably, the core taking process can be divided into at least three stages:

in the first stage when the drilled core sample enters the core accommodating cavity 224 at least in a part of the axial section, the monitoring and sensing module 51 monitors the magnitude of the radial pressure applied to the core sample in the core accommodating cavity 224 in real time and transmits the magnitude to the hydraulic pressure adjusting module 52 for comparative analysis. The hydraulic pressurizing part 21 injects hydraulic oil into the high-pressure fluid cavity 223 of the core pressurizing part 22 according to the comparison result, so as to realize a first pressurizing operation of providing radial pressure corresponding to the pre-collected ground stress data to at least part of axial sections of the drilled core in the radial direction;

under the condition that the drill bit body 1 finishes core drilling and the hydraulic pressurization part 21 finishes first pressurization operation on the drilled core, the inner cylinder assembly 2 moves along with the core transfer system 4 in the second stage of lifting the inner cylinder assembly 2 on the core transfer system 4 arranged at the axial upper end of the core pressurization part 12. The rock core claw assembly 3 is arranged at the axial lower end of the inner cylinder assembly 2 and is used for stopping the connection of the rock core and the rock body in a mode of limiting the rock core to be separated from the inner cylinder assembly 2;

in a third stage that the core gripper assembly 3 finishes truncation and limiting of the core sample after lifting along with the inner cylinder assembly 2 and the core transfer system 4 further lifts the inner cylinder assembly 2, the hydraulic adjusting module 52 performs comparative analysis on real-time radial pressure of the core sample in the lifting process monitored by the monitoring and sensing module 51 and ground stress data collected in advance. The hydraulic adjusting module 52 controls the hydraulic pressurizing part 21 to inject hydraulic oil into the high-pressure fluid cavity 223 of the core pressurizing part 22 according to the real-time pressure data comparison result according to the change of the radial pressure applied to the core sample collected by the monitoring sensing module 51 in the lifting process, so that the real-time radial pressure applied to the core sample corresponds to the pre-collected ground stress.

Example 2

As shown in fig. 4, the core gripper assembly 3 is provided with a clamp 33 and a core clamper 34 in a clamp stopper 32 in such a manner that a drilled core can be cut off and limited. The core clamping piece 34 can adjust the working position along with the movement of the clamp 33 in the clamp limiting body 32. The clamp 33 is sleeved in the inner cavity of the clamp limiting body 32 in a mode of moving up and down along the axial direction of the clamp limiting body 32. As shown in fig. 3, a limiting groove 321 for installing the core clamper 34 is formed on the inner cavity wall of the hoop limiting body 32. One end of the core catch 34 is connected with a shaft 322. When the shaft 322 is mounted on the groove wall of the limiting groove 321, the core catch 34 can enter the limiting groove 321 or can rotate out of the groove cavity of the limiting groove 321 in a manner of rotating around the shaft 322. The end of the core catch 34 connected to the shaft 322 is further provided with a torsion spring 323. Under the condition that the hoop 33 moves along the axial direction of the hoop limiting body 32 and is separated from shielding the limiting groove 321, the torsion spring 323 is sleeved on the shaft rod 322 in a manner that the rod body of the core clamping piece 34 is driven to rotate around the shaft rod 322 and move out of the limiting groove 321, and two supporting ends of the torsion spring 323 are respectively arranged on the surfaces of the limiting groove 321 and the core clamping piece 34 which form an included angle. The core clamping piece 34 comprises a support rod 341 and a limiting block 342 arranged on the support rod 341. Two torsion arms of the torsion spring 323 sleeved on the shaft rod 322 respectively abut against the surface of the limiting block 342 close to the limiting groove 321 and the bottom surface of the groove cavity of the limiting groove 321. Under torque spring's effect, the stopper receives torque spring's elasticity and to the direction motion of keeping away from spacing groove 321, and stopper 342 drives the body of rod motion of bracing piece 341 to the body of rod of bracing piece 341 can rotate the roll-off spacing groove in spacing groove 321 around its position of being connected with axostylus axostyle 322 after taking place to rotate, and keep away from the first end of axostylus axostyle 322 through bracing piece 341 and support the rock core. The clamp 33 can translate along the axial direction of the clamp limiting body 32 to change the size of the hollow ring diameter limited by the clamp 33, so that the friction force between the clamp 33 and the surface of the core can be adjusted, and the clamp 33 can fix the position of the core inside the core extracting assembly in the process of lifting the core extracting assembly.

After a core drilled by the hollow drill enters the inner cavity of the drill rod from the opening at the axial lower end of the core, the core column passes through the middle hole channel of the inner barrel assembly 2 and then enters the core accommodating cavity of the accommodating part 32. The surface of the core pillar can contact and rub with the annular inner wall of the clamp 33 to drive the clamp 33 to move upwards along the axis of the clamp limiting body 32. The diameter of the axial upper end port of the band stopper 32 is smaller than the diameter of the axial upper end of the band 33, so that the band 33 is restricted from sliding out of the axial upper end of the chamber of the band stopper 32, and the band 33 moves up and down only in the limit chamber of the band stopper 32. Under the condition of accomplishing coring operation and lifting inner tube subassembly 2, clamp 33 takes place for the downward removal of clamp spacing body 32's axial along with the operation that rises, make the interior aperture that has the limited of lateral wall open-ended clamp 33 reduce, thereby with the frictional force increase between the rock core contact surface, the rock core reduces along with the interior aperture of clamp 33 gradually, make the unchangeable spacing connection of relative position of having formed between rock core and the inner tube subassembly 2, and then in inner tube subassembly 2 continued the operation process that upwards promoted, the cracked external force of dragging between rock core and the rock mass increases gradually, finally make rock core and rock mass take place to separate.

Preferably, the collar-limiting body 32 is annularly provided with a plurality of core clamps 34 along an inner circumferential surface thereof. When lifting in-process clamp 33 and taking place relative motion and eliminate the restriction to rock core fastener 34 along the rock core, rock core fastener 34 takes place relative rotation around the inner wall groove hookup location with clamp spacing body 32 to the body of rod of rock core fastener 34 can rotate the roll-off spacing groove under torsion spring's effect, makes rock core fastener 34 keep away from the one end of being connected with clamp spacing body 32 and inlays on the rock core surface, has further guaranteed rock core and inner tube subassembly 2 relatively fixed. Can carry out spacing support to the rock core after accomplishing the coring operation through the clamp that sets up and can utilize the operation of lifting that the coring subassembly drove the rock core simultaneously to make rock core and rock mass break off to make and follow the interior section of thick bamboo subassembly and extract from drilling by the spacing fixed rock core of clamp. In addition, make the fastener body of rod can carry out the secondary to the rock core through setting up rock core fastener 34 and fix and support, especially rock core fastener body of rod front end can insert the relative fixation between further assurance rock core and the coring device in the rock core surface aslope, avoids it to drop the roll-off from the coring device.

As shown in fig. 5, the bit end 12 is disposed at the axially lower end of the drill rod 11. The end face of the drill head end 12 remote from the end of the drill rod 11 is provided with a plurality of drill bit teeth 121, constituting the cutting-in end of the drill bit. A plurality of bit teeth 121 are provided as a first working tooth 122 and a second working tooth 123 in a manner that enables the formation of two different annular drilling faces. The first working teeth 122 and the second working teeth 123 are circumferentially staggered on the end face of the bit end 12, so that a staggered bit lip face can be formed. The tooth bodies of the first working teeth 122 are arranged along the inner circumferential line of the annular end surface of the drill bit end 12, so that a plurality of first working teeth 122 on the same circumferential ring surface form a first annular working surface. The tooth bodies of the second working teeth 123 are arranged along the outer ring edge of the annular end face of the bit end 12, so that a plurality of second working teeth 123 on the same circumferential ring face form a second annular working face. The first annular working surface partially coincides with the second annular working surface. The contact area of the drill bit and the rock mass surface can be effectively reduced by arranging the staggered drill bit lip faces, so that the pressure per unit area acting on the rock mass is increased, the volume of the rock mass can be more favorably crushed, the drill bit lip faces are partially left after being left, the volume of the cuttings is increased, the cuttings are remained at the bottom of the hole in the drilling process, the cuttings not taken away by the drilling fluid are also increased, the drill bit matrix can be effectively abraded, and the drill bit is enabled to be sharper. The drill bit end 12 and the first working tooth 122 and the second working tooth 123 are integrally sintered in a mode of filling the steel body mold in layers, so that the problem that the assembled drill bit is easy to loosen or fall off is solved.

As shown in fig. 5, the spaces formed by the staggered arrangement of the tooth bodies of the first working tooth 122 and the second working tooth 123 on the same plane just can form the diversion trench 124. The channels 124 can facilitate interaction between the radially inner and outer regions of the drilling face. The drilling fluid flowing out of the axial passage at the axially lower end of the bit end 12 can flow through the flow channels 124 to the outer region of the tooth body, so that the drilling face can be lubricated better. The radially outer side of the first working tooth 122 is further provided with an outer groove 125 communicating with one end of the guide groove 124. The radially inner side of the second working tooth 123 is provided with an inner groove 126 communicating with an end of the guide groove 124 remote from the outer groove 125. Preferably, the outer and inner slots 125, 126 are each defined by sloped tooth sidewalls having a slope for the first and second working teeth 122, 123. And the groove walls of the outer groove 125 and the inner groove 126 are the tooth side walls of the bit teeth 121, and the groove body changes along with the tooth shape change of the bit teeth 121, so that rock debris generated in the drilling process can be smoothly discharged along the passage formed by the outer groove 125, the inner groove 126 and the diversion groove 124 along with the rotation of the bit. The guide groove 124, the outer groove 125, and the inner groove 126 are provided on the end surface of the axially lower end of the bit end 12. Both circumferential ends of the outer groove 125 are communicated with the adjacent guide grooves 124 provided on both sides of the same first working tooth 122. Both circumferential ends of the inner groove 126 are communicated with the adjacent guide grooves 124 provided on both sides of the same second working tooth 123. According to the invention, the side edges of the drill bit teeth are arranged to be inclined tooth surfaces, so that the side walls of the drill bit teeth are more favorably abraded by rock debris, and the front end of the drill bit can be kept sharp all the time.

Example 3

A rock core drill bit under high ground stress comprises a drill bit main body 1, an inner barrel assembly 2, a liquid storage bin 211, a conveying pipeline 212, a driving part 213, a power supply 214 and a rock core transfer system 4.

When this application carries out the rock core sample under to current high ground stress environment, because the underground rock body can receive the stratum stress effect of locating, therefore when the rock core separates from the rock body and transports out the bottom of the earth, because the pressure variation that the rock core received for the sampling operation often can't acquire the rock core sample of preserving well. In addition, it can be understood from the record in the relevant geotechnical engineering survey specifications that the current ground stress grading standard divides the initial ground stress into the following grades:

1. maximum stress value of very high ground stress vertical axis: not less than 40MPa

Hard rock: rock burst occurs during the excavation process, rock blocks are popped out, rock masses on the wall of the tunnel are stripped, and more new cracks are generated; the foundation pit has a stripping phenomenon, and the formability is poor; the core of the drill hole is mostly caked.

2. Maximum stress value of high ground stress vertical axis: 20 to 40MPa

Soft rock: the drilling rock core has a cake phenomenon, the rock mass of the wall of the hole is stripped in the excavation process, the displacement is extremely obvious, even large displacement occurs, the duration is long, and the hole is not easy to form; the foundation pit rock mass has unloading resilience, obvious swelling or stripping and difficult forming;

hard rock: rock burst may occur in the excavation process, the rock mass of the tunnel wall has stripping and block dropping phenomena, and more new cracks are generated; the stripping phenomenon exists in the foundation pit, and the formability is generally good; the phenomenon of caking exists when the core is drilled and collected.

3. Maximum stress value of medium ground stress vertical axis: 10 to 20MPa

Soft rock: the drilling core has a cake phenomenon, the displacement of the wall rock body of the hole is obvious in the excavation process, the duration is long, and the hole forming property is poor; the foundation pit has a bulging phenomenon, and the formability is poor;

hard rock: the phenomena of stripping and block dropping are generated on the part of the wall rock body in the excavation process, and the cave forming property is good; the local part of the foundation pit has a stripping phenomenon, and the formability is good.

4. Maximum stress value of low ground stress vertical axis: < 10MPa

Soft rock: in the excavation process, the wall rock body is partially displaced, and the tunneling property is good; the local part of the foundation pit has a swelling phenomenon, and the formability is generally good.

It can be seen from the relevant ground stress grading standards that the main reason for the damage of the core sample is that the rock mass is subjected to a large ground stress in the deep formation, when the core sample of the rock mass is collected, especially for the rock in a high ground stress environment, due to the difference of the positions of the formations where the rock mass is located, the initial pressure of the core in the rock mass is large, when the core is transported to the ground in the process of taking out the core, if the core sample cannot be always subjected to a certain ambient pressure, the pressure around the environment where the core is located will be suddenly reduced due to the change of the position of the core, so that the core taken out of the rock mass is subjected to a core caking phenomenon in the transportation process, the collected sample brings a large uncertain factor to subsequent core analysis work, and therefore, in order to obtain a perfect core, a pressure structure capable of applying pressure to the core is required to be arranged in the core drilling equipment, so that the extracted core can always be subjected to the same amount of pressure as it was in its initial position in the rock mass.

Therefore, in order to take a complete rock core sample in a high ground stress environment, the device improves the core barrel of the existing coring bit, and the rock core taken by the coring bit is sleeved into a one-way sealed high-wear-resistant rubber sleeve, wherein the rock core of the exposed part is subjected to stress fidelity by using a certain pressure of underground slurry, and the rock core in the rubber sleeve is subjected to stress fidelity by working and transporting a high-pressure fluid with an external equivalent pressure through a micro pump in a drill rod. This application is different from the spring stress fidelity structure among the prior art, utilizes high-pressure fluid to realize taking the stress fidelity of rock core to the extrusion force that holds the chamber cover to make the adjustability of device great, and the regulation of pressure size is accurate more accurate, and whole stress fidelity structure also has longer life for current spring structure.

Preferably, the walls of the core chamber 224 are made of a material having a certain elasticity, such as rubber. The rubber chamber wall with certain elasticity can enable the whole chamber wall to be subjected to uniform confining pressure, so that the recovery rate of stress-preserved coring is improved, and the phenomenon of core caking is prevented. As shown in fig. 7, the surface of the rubber chamber wall on the side of the core accommodating chamber 224 facing the core is also provided with a limit module 225 capable of directly contacting with the surface of the core. The limiting module 225 is a rubber block which is integrally molded with the wall of the rubber chamber, and the rubber block can be any figure such as a triangle, a quadrangle, a pentagon and the like. Preferably, the limiting module 225 and the core accommodating cavity 224 are made of rubber or other materials with high wear resistance and elasticity. As shown in fig. 6, the limiting modules 225 are uniformly arranged on the surface of the cavity wall in a manner that the core is prevented from directly rubbing against the rubber cavity wall to wear the cavity wall, so that the pressure applied by the high-pressure fluid chamber 223 on the cavity wall of the core accommodating chamber 224 can be uniformly transmitted to the limiting modules 225, and the rubber modules can apply confining pressure to the core consistent with the ambient stress applied when the core is in the rock mass. The service life of the rubber chamber wall can be effectively prolonged by arranging the limiting module, and meanwhile, the risk of hydraulic oil leakage caused by chamber wall damage is reduced. This application sets up the integrated configuration for convenient dismantlement and equipment through the rock core portion of holding 222 and the rock core inner tube 221 that will gather the parcel rock core to the convenience is at the coring in-process, only needs to change rock core portion of holding 222 according to the demand and just can accomplish the rock core collection work of the different degree of depth in same drilling. And the rock core of this application shifts adopts rope coring technique, can be in the operation process of actually coring, only need utilize wire rope to propose inner tube subassembly 2 from the well, after coring pipe is proposed from the pit, constructor accomplishes the change of inner tube subassembly 2 front end subaerial, can improve the efficiency of well drilling coring and can reduce revealing of high-pressure fluid, can carry out the replacement work of rubber matrix with very fast speed. In addition, the stress-preserving coring system and the core transfer system can cooperate closely in core sample taking, and after the stress-preserving coring system completes coring and pressurization, the core transfer system can take the inner pipe assembly 2 loaded with the core out of the outer pipe assembly according to requirements, so that the recovery rate of stress-preserving coring is improved, and the phenomenon of core caking is prevented.

The end of the core inner tube 221 away from the core accommodating part 222 is further provided with a liquid storage 211 and a driving part 213 which can convey pressurized hydraulic oil into the high-pressure fluid cavity. The liquid storage 211 is communicated with the high-pressure fluid chamber 223 through an external conveying pipeline 212, so that the driving part 213 can convey hydraulic oil in the liquid storage 211 to the high-pressure fluid chamber 223 as required. In addition, when the core inner tube 221 and the core accommodating part 222 are disassembled, redundant hydraulic oil in the high-pressure fluid chamber 223 can be conveyed back to the fluid storage chamber 211, so that the hydraulic oil is prevented from flowing out from the opening of the core inner tube 221. Preferably, the chamber volume of the liquid storage bin 211 is greater than the difference between the volume of the inner tube 221 of the rock core and the volume of the rock core, so that after the rock core enters the rock core accommodating cavity 224, the liquid volume of the high-pressure fluid cavity 223 which can be entered into the liquid storage bin 211 is far greater than the volume of the high-pressure fluid cavity 223, and then the expansion force of different sizes can be applied to the elastic cavity wall of the high-pressure fluid cavity 223 by the hydraulic oil. The pipe of the delivery pipe 212 is also connected to a driving unit 213 that can drive the hydraulic oil in the circuit. The driving part 213 adopts a micro pump which can realize the switching of the working state and adjust the driving direction of the driving force by controlling the on-off of the electric power by an electromagnetic relay, thereby providing the driving force for the hydraulic oil in the pipeline according to the requirement. In the process of core sampling, the driving part 213 controlled by the electromagnetic relay transmits high-pressure liquid flow to the high-pressure fluid chamber 223 according to the requirement, so that the input high-pressure liquid flow exerts confining pressure on the chamber wall of the core accommodating chamber 224. The driving unit 213 is also electrically connected to a power source 214 for supplying power by rope power supply or mud pulse power generation. The power source 214 is also disposed at an end of the core inner tube 221 remote from the core receiver 222.

Example 4

The application provides a rock mass coring bit under high ground stress is particularly useful for carrying out the coring work of guarantor's stress to the rock under high ground stress environment. After the core is collected from the rock mass by the coring device, the core is inserted into a core accommodating cavity 224 which is sealed in a one-way mode and is formed by a high-wear-resistant rubber sleeve, the hydraulic pressurizing part 21 injects hydraulic oil in the liquid storage bin 211 into the high-pressure fluid cavity 223 according to pre-collected ground stress data, so that the acting force of the high-pressure fluid cavity 223 on the cavity wall of the core accommodating cavity 224 is gradually increased due to the fact that the hydraulic oil in the cavity of the high-pressure fluid cavity 223 is increased, and finally the pressure applied by the cavity wall of the core accommodating cavity 224 on the core in the cavity is gradually increased to the ground stress applied to the core in the rock mass. A core abutting device is further arranged on the axial upper end cavity wall of the core accommodating cavity 224. After the core completely enters the core accommodating cavity 224, the end part of the core can abut against a core abutting device arranged on the closed end surface of the core accommodating cavity 224, and the abutting signal transmitted by the device can realize that the electromagnetic relay corresponding to the driving pump 213 controls the disconnection of the circuit. After the core drilling is completed by the coring structure, the core in the inner barrel assembly 2 is transported to the surface by wireline coring methods commonly used in the art.

In the actual exploration process, well drilling and coring are important links in core analysis work, when rock is in some very environments, particularly high ground stress environments, the rock core is cracked into a cake shape along with the relief of the stress of a hole wall in the drilling process, and the thickness of the formed cake is smaller when the ground stress is larger; the invention provides a method for applying confining pressure by high-pressure fluid to prevent the occurrence of core caking phenomenon, ensure the core stress fidelity in a high ground stress environment and improve the recovery ratio of stress-preserved coring. The stress-preserving system adopts the measures that the high-pressure fluid input in advance by the micro pump is utilized to apply confining pressure equivalent to the initial stratum to the core wrapped in the wear-resistant rubber die sleeve, stress-preserving coring is carried out on the core, and a small amount of parts of the upper end and the lower end of the core are also wrapped by the wear-resistant rubber die sleeve; and the magnitude of the stress retention provided by the static high-pressure fluid is relatively stable in the process of drill lifting, the service life is relatively long, the range of the stress retention is relatively wide, the phenomenon of core caking can be effectively prevented, and the recovery ratio of stress retention coring can be obviously improved. The advantage that this application can bring through adopting the rope coring method is extremely obvious: the method can realize coring without drilling, save drilling time, shorten construction time and reduce cost; the adoption screw thread can greatly improve the speed of boring the coring with core barrel removable assecmbly's structure that combines this application to provide, also greatly improved the recovery ratio of rock core and can reduce the emergence probability of downthehole accident. This application is repacking inner tube subassembly 2 front end for detachable component, owing to adopt the characteristics of rope coring, need not dig into, only need to mention inner tube subassembly 2 from the well with wire rope, mention the back when inner tube subassembly 2 follows the well, ground personnel can be fast with the detachable device replacement of inner tube subassembly 2 front end, greatly accelerate the speed that the rock core bored and got, and pour into high-pressure fluid into in advance subaerial after, if discover high-pressure fluid's sudden pressure drop, can judge that high-pressure fluid produces reveals, can judge before dismantling inner tube subassembly 2 whether can take place to reveal, if take place to reveal, ground personnel can change detachable device fast, can greatly improve the sealing performance of inner tube subassembly 2 front ends. In addition, the drill bit at the front end of the device is an integral high-strength drill bit, the drill bit is not an assembled drill bit, the mechanical property and the normal state of rock are greatly different in a high ground stress environment stratum, when the assembled drill bit is drilled into rock which is difficult to drill, the structure of the drill bit can be loosened, and the drill rod can deviate from a preset track and the core sampling can fail to be caused seriously; this is effectively avoided by using a high strength monolithic drill bit.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims (10)

1. A rock mass coring bit under high ground stress comprises a bit body (1), wherein an inner barrel assembly (2) used for holding and taking out a core is arranged in a radial inner chamber of a drill rod of the bit body (1), the rock mass coring bit is characterized in that a hydraulic assembly (5) is arranged on the inner barrel assembly (2) in a mode of monitoring and/or adjusting pressure applied to a core sample, the hydraulic assembly (5) at least comprises a monitoring sensing module (51) and a hydraulic adjusting module (52), wherein,

the hydraulic adjusting module (52) can adjustably change the pressure applied to the core sample by comparing the pre-collected ground stress data with the real-time pressure applied to the core sample monitored by the monitoring sensing module (51), so that at least part of the axial section of the core contained in the inner cylinder assembly (2) is subjected to radial pressure corresponding to the pre-collected ground stress data.

2. The rock mass coring bit under high ground stress as set forth in claim 1, wherein the inner barrel assembly (2) comprises at least a hydraulic pressurization part (21) and a core pressurization part (22), wherein the hydraulic pressurization part (21) changes the pressure applied by the core pressurization part (22) to the extracted core according to the comparison result of the hydraulic adjustment module (52);

the monitoring sensing module (51) is arranged on the surface of a chamber, which is in contact with the collected rock core, of the rock core pressurizing part (22).

3. A rock mass coring bit under high ground stress as set forth in claim 2 wherein the core pressing portion (22) comprises: the core accommodating part (222) is detachably connected with the core inner tube (221) to form a sealed high-pressure fluid chamber (223), wherein the core accommodating part (222) further comprises a core accommodating chamber (224) for accommodating a core sample;

in a first stage that at least part of axial section of the drilled core sample enters a core accommodating cavity (224), the monitoring and sensing module (51) monitors the magnitude of radial pressure applied to the core sample in the core accommodating cavity (224) in real time and transmits the magnitude to the hydraulic adjusting module (52) for comparative analysis, so that the hydraulic pressurizing part (21) completes a first pressurizing operation of providing radial pressure corresponding to pre-collected ground stress data to at least part of axial section of the drilled core in a radial direction in a mode of injecting hydraulic oil into a high-pressure fluid cavity (223) of the core pressurizing part (22) according to a comparative result.

4. A rock mass coring bit under high ground stress as set forth in claim 3 wherein, in the case where the bit body (1) completes core drilling and the hydraulic pressurization section (21) completes the first pressurization operation for core drilling, the second stage of lifting the inner cylinder assembly (2) on the core transfer system (4) installed at the axially upper end of the core pressurization section (12),

the inner cylinder assembly (2) moves along with the rock core transfer system (4), and therefore the rock core claw assembly (3) arranged at the axial lower end of the inner cylinder assembly (2) cuts off the connection between the rock core and the rock body in a mode of limiting the rock core to be separated from the inner cylinder assembly (2).

5. The rock mass coring bit under high ground stress of claim 4, characterized by a third stage in which the core gripper assembly (3) completes the truncation and the limitation of the core sample as the inner barrel assembly (2) is lifted and the core transfer system (4) further lifts the inner barrel assembly (2),

the hydraulic adjusting module (52) carries out comparative analysis on real-time radial pressure suffered by a core sample in the lifting process monitored by the monitoring sensing module (51) and pre-collected ground stress data,

the hydraulic adjusting module (52) controls the hydraulic pressurizing part (21) to inject hydraulic oil into the high-pressure fluid cavity (223) of the rock core pressurizing part (22) according to the real-time pressure data comparison result according to the change of the radial pressure applied to the rock core sample collected by the monitoring sensing module (51) in the lifting process, so that the real-time radial pressure applied to the rock core sample corresponds to the pre-collected ground stress.

6. The rock mass coring bit under high ground stress as recited in claim 3, wherein the core gripper assembly (3) comprises a clamp connection seat (31), a clamp limiting body (32), a clamp (33) and a core clamping piece (34), and in the initial stage of lifting the core carried by the inner barrel assembly (2), the clamp (33) moves downwards in the clamp limiting body (32) relatively due to contact friction with the core, so that the clamp (33) is radially compressed by the clamp limiting body (32) to reduce the inner ring diameter, the friction force between the contact surface of the clamp (33) and the core is increased, and the connection between the core and the rock mass is pulled off along with the lifting operation.

7. Rock mass coring bit under high ground stress according to claim 6, characterized in that in the second stage of lifting the inner barrel assembly (2), the clamp (33) slides axially downwards relative to the clamp limiting body (32), the core catch (34) adjusts its working position according to the movement of the clamp (33), wherein,

when the rock mass is in the first phase of coring, the rock core clamping piece (34) is limited in a limiting groove (321) of the clamp limiting body (32) by a clamp (33);

when the second phase of rock mass coring, core fastener (34) break away from along with the removal of clamp (33) to its restriction to core fastener (34) support the screens to the core according to the mode that its part body of rod shifted out from spacing groove (321).

8. The rock mass coring bit under high ground stress as recited in claim 7, wherein the core gripper assembly (3) comprises a clamp connection seat (31), a clamp limiting body (32), a clamp (33) and a core clamping piece (34), and in the initial stage of lifting the core carried by the inner barrel assembly (2), the clamp (33) moves downwards in the clamp limiting body (32) relatively due to contact friction with the core, so that the clamp (33) is radially compressed by the clamp limiting body (32) to reduce the inner ring diameter, the friction force between the contact surface of the clamp (33) and the core is increased, and the connection between the core and the rock mass is pulled off along with the lifting operation.

9. A rock mass coring bit under high ground stress as claimed in claim 6 wherein the bit body (1) comprises at least a drill rod (11) having an axial inner chamber and a bit end (12) connected to one end of the drill rod (11), the bit end (12) having an end remote from the drill rod (11) and having a plurality of bit teeth (121) disposed on an end face thereof, wherein the plurality of bit teeth (121) are arranged as first working teeth (122) and second working teeth (123) in a manner to form two different annular drilling faces, the first working teeth (122) and second working teeth (123) being circumferentially staggered on the end face of the bit end (12).

10. The use method of the rock core bit under the high ground stress is characterized in that an inner cylinder assembly (2) capable of holding and taking out a core is installed in a radial inner cavity of a drill rod (12) of an outer cylinder assembly (1), and the inner cylinder assembly (2) is provided with a core pressurizing part (22) in a mode of providing radial pressure for a core sample entering the inner cavity of the drill rod (12);

the inner cylinder assembly (2) further comprises a hydraulic pressurization part (21) which can provide radial pressure corresponding to the pre-collected ground stress data to the rock core in the rock core pressurization part (22) according to the pre-collected ground stress data.

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