Coal seam sampling device, system and method capable of self-sealing and in-hole desorption

Abstract

The present application provides a coal seam sampling device, system and method capable of self-sealing and in-hole desorption. The coal seam sampling device is used for upward drilling and coring, and a first mounting groove and a first medium channel are provided on the main drill bit, and a plurality of latch holes are provided on the bottom surface of the first mounting groove; the first sealing groove on the main drill bit is connected with the first medium channel; the upper end surface of the coring tube is provided with a first sealing boss, and the lower end surface is provided with a second mounting groove; the end surface of the first sealing boss is provided with a second medium channel, and the upper end of the second medium channel is connected with the first medium channel; a coal sample compartment is provided axially at the upper end of the coring tube, and a third mounting groove is provided circumferentially on the inner side wall of the coal sample compartment, and an expansion capsule is installed in the third mounting groove; a desorption channel and an expansion channel are provided axially on the coring tube, and the upper end of the expansion channel is connected with the third mounting groove, and the upper end of the desorption channel is connected with the lower part of the coal sample compartment, and a plurality of positioning pins adapted to the plurality of latch holes are provided on the auxiliary drill bit.

Description

Technical Field

[0001] The present application relates to the field of coal mine machinery technology, and in particular to a coal seam sampling device, system and method capable of self-sealing and in-hole desorption. Background Art

[0002] Gas is a gas that exists in coal seams. Accurately measuring the original gas content of coal seams has a huge impact on the design of coal mine gas extraction, which can directly determine whether the coal seam has the danger of coal and gas outbursts. At the same time, accurately measuring the residual gas content of coal seams after taking extraction measures is one of the important means to verify whether the extraction meets the standards. In addition, according to relevant requirements: high-gas mines must extract gas from coal seams before and during mining, and can only be mined after the extraction meets the standards; outburst mines require large-scale gas pre-extraction in coal seam areas with outburst risks, and mining operations can only be carried out after the pre-extraction effect is tested to meet the standards.

[0003] Therefore, accurate measurement of coal seam gas content is crucial to safe production in coal mines. Summary of the invention

[0004] The purpose of the present application is to provide a coal seam sampling device, system and method capable of self-sealing and in-hole desorption, so as to solve or alleviate the problems existing in the above-mentioned prior art.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] The present application provides a coal seam sampling device capable of self-sealing and in-hole desorption, which is used for upward drilling and coring, and the coal seam sampling device comprises: a main drill bit, a coring tube, an expansion capsule, an auxiliary drill bit and a connecting drill rod; one end of the main drill bit is axially provided with a first mounting groove and a first medium channel, the bottom surface of the first mounting groove is provided with a plurality of pin holes, and the first medium channel is located on the outside of the first mounting groove; the bottom surface of the main drill bit is provided with a first sealing groove, the first sealing groove is located on the outside of the first mounting groove and is connected to the first medium channel; the upper end surface of the coring tube is axially provided with a first sealing boss, and the lower end surface of the coring tube is provided with a second mounting groove; the first sealing boss is adapted to the first sealing groove, a second medium channel is provided on the end surface of the first sealing boss, and the upper end of the second medium channel is connected to the first medium channel. The channels are connected, and the lower end of the second medium channel is connected to the second mounting groove; a coal sample compartment is axially provided at the upper end of the core sampling tube, and the coal sample compartment has the same size as the first mounting groove, and a third mounting groove is circumferentially provided on the inner wall of the coal sample compartment, and the third mounting groove is used to install the expansion capsule, and a desorption channel and an expansion channel are axially provided on the core sampling tube, and the upper end of the expansion channel is connected to the third mounting groove, and the upper end of the desorption channel is connected to the lower part of the coal sample compartment, and the upper end is located below the third mounting groove, and the lower end of the desorption channel and the lower end of the expansion channel both radially penetrate the outer wall of the core sampling tube; a plurality of positioning pins are provided on the auxiliary drill bit, and the plurality of positioning pins are matched with the plurality of pin holes, and the auxiliary drill bit can move axially in the first mounting groove and the coal sample compartment.

[0007] Preferably, the inner side wall of the first mounting groove is provided with an internal thread; and / or the outer side wall of the first sealing groove is provided with an internal thread.

[0008] Preferably, the cross section of the second medium channel is fan-shaped; there are two second medium channels, the two second medium channels are symmetrically arranged, and the desorption channel and the expansion channel are spaced apart from the two second medium channels.

[0009] Preferably, the method further comprises: a pressing plate, wherein the pressing plate presses the expansion capsule into the third installation groove via a fastener.

[0010] Preferably, it also includes: a connecting drill rod, the upper end of which is sealedly connected to the lower end of the core tube, and a pipeline groove is provided on the side wall of the connecting drill rod, in which a pipeline connecting the lower end of the desorption channel and the lower end of the expansion channel is placed.

[0011] Preferably, a connecting boss is provided at the upper end of the connecting drill rod, the connecting boss is threadedly connected to the second mounting groove, and the lower end of the second medium channel is located above the top surface of the connecting boss.

[0012] Preferably, a third medium channel is provided on the connecting drill rod, the third medium channel axially penetrates the connecting drill rod, and the third medium channel is communicated with the second medium channel.

[0013] Preferably, a threaded connection hole coaxial with the third medium channel is provided at the lower end of the connecting drill rod.

[0014] An embodiment of the present application also provides a coal seam sampling system that is self-sealing and capable of in-hole desorption, comprising any of the above-mentioned coal seam sampling devices that are self-sealing and capable of in-hole desorption, a pressure pump and a gas desorber, the gas desorber being connected to a desorption channel in the coal seam sampling device, the pressure pump being connected to an expansion channel in the coal seam sampling device, a desorption control valve being arranged on the connecting pipe between the gas desorber and the coal seam sampling device, and a liquid injection control valve being arranged on the connecting pipe between the pressure pump and the coal seam sampling device.

[0015] The embodiment of the present application also provides a coal seam sampling method capable of self-sealing and in-hole desorption, adopting any of the above-mentioned coal seam sampling systems capable of self-sealing and in-hole desorption, the coal seam sampling method comprising: step S101, inverting the main drill bit, aligning the auxiliary drill bit with the pin hole of the main drill bit for connection, and connecting the core tube to the main drill bit; step S102, injecting liquid into the expansion capsule through the liquid channel to expand the expansion capsule and squeeze the auxiliary drill bit onto the main drill bit; injecting gas into the cavity below the expansion capsule through the gas channel to confirm the airtightness of the coal seam sampling device; step S103, depressurizing the coal seam sampling device, disassembling it, bringing it into the well for reassembly, and reassembling the coal seam sampling device. After the coring tube of the sampling device is connected to the drilling rig, hole drilling is carried out; step S104, in response to the coal seam sampling device reaching the preset coring position, the expansion capsule is depressurized, the expansion capsule shrinks to its original position, and the auxiliary drill bit falls under the action of its own weight; step S105, in response to the coal blocks in the coal sampling compartment reaching the range of 1 / 3 to 1 / 2 of its volume, coring is completed and drilling is stopped; step S106, liquid is injected through the expansion channel, and the pressure in the expansion capsule is maintained at not less than 5 MPa, so that the expansion capsule expands and closes the coal sampling compartment; synchronously, the coal sample in the coal sampling compartment is desorbed through the gas channel; step S107, during the desorption of the coal sample in the coal sampling compartment, synchronous drilling can be carried out.

[0016] Beneficial effects:

[0017] The coal seam sampling device capable of self-sealing and in-hole desorption provided in the embodiment of the present application comprises: a main drill bit, a coring tube, an expansion capsule, an auxiliary drill bit and a connecting drill rod; a first mounting groove and a first medium channel are axially arranged at one end of the main drill bit, a plurality of latch holes are arranged on the bottom surface of the first mounting groove, the first medium channel is located on the outside of the first mounting groove, a first sealing groove is arranged on the bottom surface of the main drill bit, the first sealing groove is located on the outside of the first mounting groove and is connected to the first medium channel; a first sealing boss is axially arranged on the upper end surface of the coring tube, a second mounting groove is arranged on the lower end surface of the coring tube, the first sealing boss is matched with the first sealing groove, a second medium channel is arranged on the end surface of the first sealing boss, the upper end of the second medium channel is connected to the first medium channel, and the sealing boss is connected to the first medium channel. The channels are connected, and the lower end of the second medium channel is connected to the second mounting groove; a coal sample compartment is axially provided at the upper end of the core tube, and the size of the coal sample compartment is the same as that of the first mounting groove, and a third mounting groove is circumferentially provided on the inner wall of the coal sample compartment, and an expansion capsule is installed in the third mounting groove, and a desorption channel and an expansion channel are axially provided on the lower end face of the core tube, the upper end of the expansion channel is connected to the third mounting groove, the upper end of the desorption channel is connected to the lower part of the coal sample compartment, and the upper end is located below the third mounting groove, and the lower end of the desorption channel and the lower end of the expansion channel both radially penetrate the outer wall of the core tube; a plurality of positioning pins are provided on the auxiliary drill bit, and the plurality of positioning pins are matched with the plurality of pin holes, and the auxiliary drill bit can move axially in the first mounting groove and the coal sample compartment.

[0018] Thus, the expansion channel is used to inject high-pressure liquid to expand the expansion capsule, seal the core tube radially, and press the auxiliary drill bit against the main drill bit for drilling; during the coring process, the expansion capsule is depressurized and shrinks back to its original position, the auxiliary drill bit falls to the bottom of the coal sample compartment, the main drill bit continues to drill, and the coal blocks fall into the coal sample compartment; then high-pressure liquid is injected again to expand the expansion capsule and seal the coal sample compartment; desorption is carried out through the desorption channel. During the whole process, there is no need to withdraw the drill and replace the coring drill bit, which greatly saves the time of coring the coal seam. After the coring is completed, desorption can be carried out immediately, and the coal sample can still be desorbed during the withdrawal process, effectively improving the desorption accuracy; the coal sample compartment is sealed by the expansion capsule, which can be expanded or retracted as needed, not only with good sealing effect, but also can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. Among them:

[0020] Figure 1 A schematic structural diagram of a coal seam sampling device capable of self-sealing and in-hole desorption provided according to some embodiments of the present application;

[0021] Figure 2 for Figure 1A cross-sectional view of a coal seam sampling device capable of self-sealing and in-hole desorption;

[0022] Figure 3 for Figure 2 BB view in the view shown;

[0023] Figure 4 A schematic diagram of the structure of a main drill bit provided according to some embodiments of the present application;

[0024] Figure 5 A schematic diagram of the structure of a core tube provided according to some embodiments of the present application;

[0025] Figure 6 for Figure 5 EE view in the shown view;

[0026] Figure 7 for Figure 6 The GG view in the shown view;

[0027] Figure 8 A schematic diagram of the structure of an auxiliary drill bit provided according to some embodiments of the present application;

[0028] Fig. 9 A schematic diagram of the structure of a connected drill pipe provided according to some embodiments of the present application;

[0029] Fig.10 for Fig. 9 A cross-sectional view of an embodiment of a connected drill pipe shown;

[0030] Fig.11 A schematic structural diagram of a coal seam sampling system capable of self-sealing and in-hole desorption provided according to some embodiments of the present application;

[0031] Fig.12 A schematic diagram of the connection between a gas desorption hose and a gas desorption device according to an embodiment of the present application;

[0032] Fig.13 A schematic diagram of the connection between a liquid injection high-pressure hose and a pressure pump according to some embodiments of the present application;

[0033] Fig.14 A schematic flow chart of a coal seam sampling method capable of self-sealing and in-hole desorption provided according to some embodiments of the present application.

[0034] Description of reference numerals:

[0035] 100. Coal seam sampling device; 200. Drilling rig; 300. Gas desorption instrument; 400. Pressure pump; 500. Gas desorption hose; 600. Liquid injection high-pressure hose;

[0036] 101. Main drill bit; 102. Coring tube; 103. Connecting drill rod; 104. Auxiliary drill bit; 105. Expansion capsule;

[0037] 111, first medium channel; 121, first sealing groove; 131, first mounting groove; 141, latch hole;

[0038] 112, first sealing boss; 122, second sealing groove; 132, third mounting groove; 142, second medium channel; 152, second mounting groove; 162, desorption channel; 172, expansion channel;

[0039] 113, connecting boss; 123, third medium channel; 133, pipeline groove; 143, fixing groove; 153, threaded connection hole;

[0040] 114. Positioning pin;

[0041] 501, external thread of desorption interface; 502, desorption control valve; 503, desorption quick connector; 601, external thread of injection interface; 602, injection control valve; 603, injection quick connector. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present application and does not limit the present application. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present application without departing from the scope or spirit of the present application. For example, a feature shown or described as a part of an embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present application includes such modifications and variations within the scope of the appended claims and their equivalents.

[0043] At present, the methods for determining the gas content of coal seams are mainly divided into direct method and indirect method. Among them, the indirect method is to calculate the gas content using the Langmuir equation based on the original gas pressure of the coal seams measured on site, the coal adsorption constant value measured in the laboratory, and the industrial analysis results. Due to the shortcomings of this method, such as complex process, long cycle and low success rate for determining the original gas pressure of coal seams, it is rarely used on coal mine sites.

[0044] The direct method is to directly take coal samples and directly measure and calculate the coal seam gas content by studying its desorption law. Compared with the indirect method, the direct method has a short measurement cycle, low cost and the detection instrument can be reused. The direct method is often used in coal mines to measure the coal seam gas content. The key link of the direct method is the coring of coal samples, and the quality of coring is directly related to the results of coal seam gas content measurement. The key factors for successful coal coring mainly lie in its integrity, quality preservation and rapidity, and the key to meeting the above three factors lies in the coal seam sampling device. However, the current coal seam sampling device, first, cannot achieve rapid coring, resulting in large gas loss, affecting the actual coal seam gas content results; second, the sampling device has a complex structure and contains multiple components, which is difficult to process and manufacture; third, the sealing mechanism is unreliable and is easily affected by construction conditions during the actual drilling and coring process; fourth, the sampling device has a poor sealing effect and there is leakage, which cannot achieve real-time desorption and cannot accurately obtain the true desorption curve and results.

[0045] Based on this, the applicant proposed a self-sealing and in-hole desorbable coal seam sampling device 100 for upward drilling and coring, which mainly includes: a main drill bit 101, a coring tube 102, an expansion capsule 105, an auxiliary drill bit 104 and a connecting drill rod 103; high-pressure liquid is injected into the expansion channel 172 to expand the expansion capsule 105, radially seal the coring tube 102, and press the auxiliary drill bit 104 against the main drill bit 101 for drilling; during the coring process, the expansion capsule 105 is depressurized and shrinks back to its original position, the auxiliary drill bit 104 falls to the bottom of the coal sample compartment, the main drill bit 101 continues to drill, and the coal blocks fall into the coal sample compartment; then high-pressure liquid is injected again to expand the expansion capsule 105 and seal the coal sample compartment; desorption is carried out through the desorption channel 162. The coring process is completed in one step, and there is no need to withdraw the drill or replace the coring drill bit during the coring process, which greatly saves the time for coal seam coring, reduces the coring procedures and steps, and improves the coring speed; and after the coring is completed, the coal sample can be desorbed, which effectively reduces gas loss and improves the desorption accuracy; the expansion capsule 105 is expanded by high pressure to achieve sealing, with a short sealing time and good effect, and the expansion capsule 105 can be reused; at the same time, the coal sample is desorbed during the process of withdrawing the drill, which effectively reduces the pressure intensity of the gas in the coal sample chamber during the entire process of withdrawing the drill, thereby effectively reducing the difficulty of sealing and the amount of gas leakage; the entire sampling device adopts a modular design with a simple structure, can be quickly disassembled, transported, and maintained, and has strong on-site adaptability.

[0046] like Figures 1 to 10As shown, in the self-sealing and in-hole desorbable coal seam sampling device 100, a first mounting groove 131 and a first medium channel 111 are radially provided at one end of the main drill bit 101, a plurality of pin holes 141 are provided on the bottom surface of the first mounting groove 131, and the first medium channel 111 is located on the outside of the first mounting groove 131; a first sealing groove 121 is provided on the bottom surface of the main drill bit 101, and the first sealing groove 121 is located on the outside of the first mounting groove 131 and is connected to the first medium channel 111.

[0047] Among them, the head of the main drill bit 101 is provided with cutting teeth, and a first mounting groove 131 is arranged axially upward at the bottom, and four pin holes 141 are evenly arranged on the bottom surface of the first mounting groove 131, and the pin holes 141 are blind holes; between the side wall of the first mounting groove 131 and the outer wall of the rotary drill bit, an annular first sealing groove 121 is arranged on the bottom surface, and a first medium channel 111 is opened upward on the bottom surface of the first sealing groove 121, and the upper end of the first medium channel 111 is radially connected to the cutting teeth, and the drill bit is ventilated or watered during operation through the first medium channel 111 to flush the cutting teeth to crush the coal and rock mass under cutting.

[0048] The core tube 102 is connected to the lower end of the main drill bit 101 , and a first sealing boss 112 and an annular second sealing groove 122 are provided on the upper end surface of the core tube 102 , and the annular second sealing groove 122 is located on the inner side of the first sealing boss 112 ; the first sealing boss 112 is located in the first sealing groove 121 .

[0049] A second sealing boss is formed between the first sealing groove 121 and the inner side wall of the first mounting groove 131. The second sealing boss is located in the second sealing groove 122, and an internal thread is provided on the inner side wall of the second sealing boss so that it is threadedly connected with the side wall of the second sealing groove 122, thereby threading the upper end of the core tube 102 with the main drill bit 101. Furthermore, an internal thread can also be provided on the outer side wall of the first sealing groove 121 so that it is threadedly connected with the side wall of the first sealing boss 112, thereby enhancing the connection strength and stability between the core tube 102 and the main drill bit 101. Moreover, through the cooperation of the first sealing groove 121, the first sealing boss 112, the second sealing groove 122, and the second sealing boss, a tight sealing connection between the main drill bit 101 and the core tube 102 is achieved, and the sealing performance of the connection between the main drill bit 101 and the core tube 102 is effectively enhanced.

[0050] A second medium channel 142 is axially provided on the upper end surface of the first sealing boss 112 of the core tube 102. After the first sealing boss 112 is matched with the first sealing groove 121, the second medium channel 142 is connected to the first medium channel 111. A second mounting groove 152 is axially provided on the lower end surface of the core tube 102. The lower end of the second medium channel 142 is radially connected to the second mounting groove 152. The cross section of the second medium channel 142 is fan-shaped. On the one hand, it is convenient to connect with the porous first medium channel 111, and increase the matching area of ​​the second medium channel 142 and the first medium channel 111 when connected. On the other hand, the area of ​​the fan-shaped second medium channel 142 is much larger than the area of ​​the porous first medium channel 111. In the process of ventilation or water flow, the speed and pressure of the medium (wind, water) entering the first medium channel 111 from the second medium channel 142 can be effectively enhanced, and the flushing effect on the coal and rock mass under the crushing and cutting of the cutting teeth can be improved.

[0051] A coal sample compartment is axially provided at the upper end of the core sampling tube 102, and the coal sample compartment is in the shape of a blind hole along the axial direction. A third mounting groove 132 is circumferentially provided on the inner wall of the coal compartment. The third mounting groove 132 is milled out by an inner hole milling cutter and is stepped, and the expansion capsule 105 is installed on the stepped surface of the third mounting groove 132. Specifically, a plurality of mounting screw holes are circumferentially provided on the stepped surface, and the expansion capsule 105 is a cylindrical structure, and through holes matching the mounting screw holes are opened axially at the upper and lower ends. After the upper and lower ends of the expansion capsule 105 are attached to the stepped surface of the third mounting groove 132, the compression plate is used to press the expansion capsule 105 on the stepped surface of the third mounting groove 132 through fasteners.

[0052] In the present application, it is necessary to achieve sealing of the coal sample compartment through radial expansion of the expansion capsule 105. Therefore, an expansion channel 172 is axially provided between the coal sample compartment and the outer wall of the core tube 102. The upper end of the expansion channel 172 is connected to the third mounting groove 132. The lower end of the expansion channel 172 radially penetrates the outer wall of the core tube 102, and a pipeline groove 133 is opened on the outer wall of the core tube 102 from the lower end surface upward, and the pipeline groove 133 extends to the lower end of the expansion channel 172. Thereby, during the drilling process, a pipeline connected to the lower end of the expansion channel 172 for injecting high-pressure liquid into the third mounting groove 132 can be placed in the pipeline groove 133 and rotate with the core tube 102.

[0053] In addition, a desorption channel 162 is also provided axially between the coal sample compartment and the outer wall of the core sampling tube 102, and the upper end of the desorption channel 162 is connected to the coal sample compartment, and the upper end of the desorption channel 162 is located below the third mounting groove 132, so that after the coring is completed, the expansion capsule 105 expands, and the gas desorbed from the coal block in the coal sample compartment below flows out through the guidance of the desorption channel 162. Among them, a plurality of gas channel openings are provided on the inner wall of the coal sample compartment, and the plurality of gas channel openings are all connected to the desorption channel 162, so that the coal blocks can be effectively prevented from blocking the gas channel openings, and a filter can be provided at each gas channel opening to further prevent the gas channel openings from being blocked.

[0054] The lower end of the desorption channel 162 adopts the same structural layout as the lower end of the expansion channel 172, whereby the second medium channel 142, the desorption channel 162 and the expansion channel 172 are arranged between the coal sample compartment and the outer wall of the core tube 102. Here, there are two second medium channels 142 with fan-shaped cross sections, and the two second medium channels 142 are symmetrically arranged along the axis of the core tube 102, and the desorption channel 162, the expansion channel 172 and the two second medium channels 142 are arranged at intervals.

[0055] During the process of drilling into the rock formation, the auxiliary drill bit 104 of the present application is squeezed by the expansion capsule 105 and pressed tightly into the first mounting groove 131 of the main drill bit 101; specifically, a plurality of positioning pins 114 are provided on the auxiliary drill bit 104, and the plurality of positioning pins 114 are adapted to the plurality of pin holes 141. During the process of drilling into the rock formation, the blades and cutting teeth (made of diamond or cemented carbide) on the head of the auxiliary drill bit 104 are inserted into the pin holes 141, and extend from the center of the main drill bit 101 to crush the coal rock.

[0056] During the process of drilling into the rock formation, the auxiliary drill bit 104 and the main drill bit 101 become a whole through the positioning pin 114 or the pin hole 141; during the coring process, the expansion capsule 105 shrinks and recovers, and the auxiliary drill bit 104 regains its freedom and moves axially in the first mounting groove 131 and the coal sample compartment. Specifically, under the action of its own weight, it falls from the first mounting groove 131 to the bottom of the coal sample compartment (if it does not fall to the bottom of the coal sample compartment, it will also fall to the bottom of the coal sample compartment due to the squeezing of the broken coal blocks above during the drilling process of the main drill bit 101). Therefore, in this application, the coal sample compartment is the same size as the first mounting groove 131, so that the auxiliary drill bit 104 can fall during the coring process. As the main drill bit 101 continues to drill, the broken coal blocks will continue to enter the coal sample compartment. When the coal blocks in the coal sample compartment reach 1 / 3-1 / 2 of the volume, the coring is completed.

[0057] Due to different coring depths under different geological conditions, the present application further improves the scope of application of the sampling device through a detachable connecting drill rod 103. Among them, a pipeline groove is provided on the side wall of the connecting drill rod 103, and a pipeline connecting the lower end of the desorption channel 162 and the lower end of the expansion channel 172 is placed in the pipeline groove, so that this part of the pipeline can rotate together during the drilling and coring process. Among them, the pipeline groove 133 is evenly distributed along the circumference on the outer side wall of the connecting drill rod 103. And a fixed groove 143 is provided along the circumference on the outer side wall of the connecting drill rod 103. When the pipeline connecting the expansion channel 172 and the desorption channel 162 is placed in the pipeline groove 133, the pipeline is tied by thin iron wire, clamp, cable tie, etc. to fix it. The fixed groove 143 can effectively organize the thin iron wire, clamp, cable tie, etc. to jump axially.

[0058] The upper end of the connecting drill rod 103 is sealedly connected to the lower end of the core tube 102. Specifically, a connecting boss 113 and a third medium channel 123 are provided on the connecting rod. The connecting boss 113 is provided with an external thread, which is threadedly connected to the second mounting groove 152. The third medium channel 123 axially penetrates the connecting drill rod 103 from the top surface of the connecting boss 113 downward. After the connecting boss 113 is threadedly connected to the second mounting groove 152, the top surface of the connecting boss 113 is located below the second medium channel 142, so that ventilation or water can be passed into the second medium channel 142 through the third medium channel 123.

[0059] A threaded connection hole 153 coaxial with the third medium channel 123 is provided at the lower end of the connecting drill rod 103 , and the connecting bosses 113 of two adjacent connecting drill rods 103 are connected to the threaded connection hole 153 to achieve a fastening connection between the two adjacent connecting drill rods 103 .

[0060] like Figures 11 to 13 As shown, the present application also provides a coal seam sampling system that can be self-sealed and desorbed in the hole. By using the coal seam sampling device 100, the pressure pump 400, and the gas desorber 300 of the present application, the coal sample can be desorbed after the coring is completed, effectively reducing gas loss and improving desorption accuracy. Among them, the gas desorber 300 is connected to the desorption channel 162 in the coal seam sampling device 100, the pressure pump 400 is connected to the expansion channel 172 in the coal seam sampling device 100, the gas desorber 300 is connected to the coal seam sampling device 100 through the gas desorption hose 500, and the pressure pump 400 is connected to the coal seam sampling device 100 through the liquid injection high-pressure hose 600.

[0061] Specifically, the gas desorption hose 500 includes a desorption interface external thread 501, a desorption control valve 502 (desorption ball valve) and a desorption quick connector 503, wherein the desorption interface external thread 501 is located at one end of the gas desorption hose 500, and is connected to the internal thread at the lower end of the desorption channel 162, and the desorption ball valve and the desorption quick connector 503 are located at the other end of the gas desorption hose 500, which are respectively used to control the desorption gas circulation and connect the gas desorption instrument 300.

[0062] The two ends of the liquid injection high-pressure hose 600 are respectively provided with an injection interface external thread 601, an injection control valve 602 (injection ball valve) and an injection quick connector 603, wherein the injection interface external thread 601 is located at one end of the liquid injection high-pressure hose 600, and is connected to the internal thread at the lower end of the expansion channel 172, and the liquid injection quick connector 603 is mainly connected to the pressure pump 400 through a high-pressure pipeline, and a liquid injection ball valve is provided on one side of the liquid injection quick connector 603 to control the injection state.

[0063] like Fig.14 As shown, the present application also provides a coal seam sampling method capable of self-sealing and in-hole desorption, and the coal seam sampling system of the present application is used to perform coal seam sampling, and the method comprises:

[0064] Step S101 , invert the main drill bit 101 , align the auxiliary drill bit 104 with the pin hole 141 of the main drill bit 101 for connection, and connect the core tube 102 to the main drill bit 101 .

[0065] Specifically, the main drill bit 101 is inverted on the ground, and the positioning pin 114 on the auxiliary drill bit 104 is aligned with the pin hole 141 on the main drill bit 101, and the auxiliary drill bit 104 is assembled with the main drill bit 101; then, the core tube 102 is threadedly connected to the main drill bit 101. At this time, the core tube 102, the main drill bit 101, and the auxiliary drill bit 104 are all inverted on the bottom surface; then, a connecting drill rod 103 is connected to the core tube 102, and the high-pressure liquid injection hose and the gas desorption hose 500 are connected to the expansion channel 172 and the desorption channel 162 respectively.

[0066] Step S102, inject liquid into the expansion capsule 105 through the liquid channel to expand the expansion capsule 105 and squeeze the auxiliary drill bit 104 onto the main drill bit 101; inject gas into the cavity (coal sample chamber) below the expansion capsule 105 through the gas channel to confirm the air tightness of the coal seam sampling device 100.

[0067] Specifically, the gas desorption hose 500 and the high-pressure liquid injection hose are connected to the gas injection equipment and the pressure pump 400 respectively. The high-pressure liquid is injected under pressure, and the pressure is greater than 5 MPa to expand the expansion capsule 105. Then, the liquid injection is stopped and the liquid injection ball valve is closed. At this time, the expansion capsule 105 expands to seal the coal sample compartment, and the auxiliary drill bit 104 is pressed against the main drill bit 101, so that the auxiliary drill bit 104 and the main drill bit 101 are connected as a whole through the positioning pin 114 and the pin hole 141. Then, 1-5 MPa of gas is injected into the coal sample compartment through the gas injection equipment box, and then the desorption ball valve is closed, and the pressure gauge is connected. It is left for 1-2 days to check the changes in the gas pressure in the coal sample compartment.

[0068] Step S103, the coal seam sampling device 100 is depressurized and disassembled and then brought underground for reassembly, and the core tube 102 of the coal seam sampling device 100 is connected to the drilling rig 200 before drilling.

[0069] After the air tightness inspection of the sampling device is qualified, the coal seam sampling device 100 is depressurized and disassembled and then brought underground for reassembly. During the underground assembly, the gas desorption hose 500 and the high-pressure injection hose are not connected. After the assembly is completed, the core tube 102 of the coal seam sampling device 100 is connected to the drilling rig 200 at a specific position and angle, fixed on the chuck of the drilling rig 200, the drilling rig 200 is started, and the coal seam sampling device 100 is tested to see whether it can cooperate with the drilling rig 200 for drilling. Here, it should be noted that control valves are respectively set at the lower ends of the desorption channel 162 and the expansion channel 172. When the core tube 102 rotates with the drilling rig 200, the control valve is closed.

[0070] Step S104, in response to the coal seam sampling device 100 reaching the preset coring position, the expansion capsule 105 is depressurized, the expansion capsule 105 shrinks to the original position, and the auxiliary drill bit 104 falls under the action of its own weight.

[0071] The drilling operation is performed on the coal rock until the hole depth reaches 1 / 3 to 1 / 2 of the coal seam sampling device 100, the connecting drill rod 103 is added, and the gas desorption hose 500 and the high-pressure liquid injection hose are respectively connected to the desorption channel 162 and the expansion channel 172, the control valves at the lower ends of the desorption channel 162 and the expansion channel 172 are opened, and the gas desorption hose 500 and the high-pressure liquid injection hose are fixed in the pipeline groove 133 by thin iron wires, clamps, cable ties, etc. When the preset coring position is reached, the liquid injection ball valve is opened to relieve the pressure on the expansion capsule 105, the expansion capsule 105 shrinks to the original position, and the auxiliary drill bit 104 falls under the action of its own weight.

[0072] Step S105, in response to the coal blocks in the coal sample compartment reaching the range of 1 / 3 to 1 / 2 of its volume, coring is completed and drilling is stopped.

[0073] As the main drill bit 101 continues to drill, broken coal blocks will continue to enter the coal sample compartment. When the coal blocks in the coal sample compartment reach 1 / 3-1 / 2 of the volume, coring is completed and drilling is stopped.

[0074] Step S106, injecting liquid through the expansion channel 172, and maintaining the pressure in the expansion capsule 105 not less than 5 MPa, so that the expansion capsule 105 expands and seals the coal sample chamber; synchronously, starting to desorb the coal sample in the coal sample chamber through the gas channel.

[0075] At this time, connect the high-pressure injection hose to the pressure pump 400, make the expansion capsule 105 expand rapidly and seal the coal sample chamber, then close the injection ball valve to keep the internal pressure of the expansion capsule 105 not less than 5 MPa; simultaneously connect the gas desorption hose 500 to the gas desorption instrument 300, and open the desorption ball valve to start desorbing the coal sample.

[0076] Step S107: During the desorption process of the coal sample in the coal sample compartment, the drill can be withdrawn synchronously.

[0077] After coring is completed, the connecting drill rod 103 is removed in sequence according to the normal drilling withdrawal procedure, and during the drilling withdrawal process, the thin iron wire, clamp, tie and other fixings on the connecting drill rod 103 are gradually removed. The desorption of the coal sample gas in the coal sample compartment will not be affected during the drilling withdrawal process, so normal desorption can be maintained during the drilling withdrawal process.

[0078] When the drill is withdrawn and the coal seam sampling device 100 is taken out, if the coal blocks inside the coal seam sampling device 100 are still undergoing rapid gas desorption, the desorption can be carried out for 30 to 60 minutes underground. If the amount of gas desorption is not large, the control valves at the lower ends of the desorption channel 162 and the expansion channel 172 on the core tube 102 can be closed, the connection between the gas desorption hose 500 and the high-pressure injection hose and the core tube 102 can be disconnected, and the coal seam sampling device 100 can be sent to the laboratory for degassing, weighing and other tests.

[0079] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coal seam sampling device capable of self-sealing and in-hole desorption, characterized in that: Used for upward drilling and coring, the coal seam sampling device comprises: a main drill bit, a coring tube, an expansion capsule, an auxiliary drill bit and a connecting drill rod; A first mounting groove and a first medium channel are axially provided at one end of the main drill bit, a plurality of pin holes are provided on the bottom surface of the first mounting groove, and the first medium channel is located outside the first mounting groove; a first sealing groove is provided on the bottom surface of the main drill bit, and the first sealing groove is located outside the first mounting groove and communicated with the first medium channel; The upper end surface of the core tube is axially provided with a first sealing boss, and the lower end surface of the core tube is provided with a second mounting groove; the first sealing boss is adapted to the first sealing groove, and a second medium channel is provided on the end surface of the first sealing boss, the upper end of the second medium channel is communicated with the first medium channel, and the lower end of the second medium channel is communicated with the second mounting groove; A coal sampling compartment is axially provided at the upper end of the core sampling tube, and the size of the coal sampling compartment is the same as that of the first mounting groove. A third mounting groove is circumferentially provided on the inner side wall of the coal sampling compartment, and the expansion capsule is installed in the third mounting groove. A desorption channel and an expansion channel are axially provided on the core sampling tube, and the upper end of the expansion channel is communicated with the third mounting groove, and the upper end of the desorption channel is communicated with the lower part of the coal sampling compartment, and the upper end is located below the third mounting groove, and the lower ends of the desorption channel and the expansion channel both radially penetrate the outer side wall of the core sampling tube; The auxiliary drill bit is provided with a plurality of positioning pins, the plurality of positioning pins are matched with the plurality of pin holes, and the auxiliary drill bit can move axially in the first mounting groove and the coal sample compartment.

2. The self-sealing and in-hole desorption coal seam sampling device according to claim 1 is characterized in that: The inner side wall of the first installation groove is provided with an internal thread; and / or the inner side wall of the first sealing groove is provided with an internal thread.

3. The self-sealing and in-hole desorption coal seam sampling device according to claim 1 is characterized in that: The cross section of the second medium channel is fan-shaped; There are two second medium channels, which are symmetrically arranged. The desorption channel and the expansion channel are spaced apart from the two second medium channels.

4. The self-sealing and in-hole desorption coal seam sampling device according to claim 1 is characterized in that: Also includes: A pressing plate, wherein the pressing plate presses the expansion capsule into the third mounting groove through a fastener.

5. The self-sealing and in-hole desorption coal seam sampling device according to claim 1 is characterized in that: Also includes: A connecting drill pipe, the upper end of which is sealedly connected to the lower end of the core tube, and a pipeline groove is provided on the side wall of the connecting drill pipe, in which a pipeline connecting the lower end of the desorption channel and the lower end of the expansion channel is placed.

6. The self-sealing and in-hole desorption coal seam sampling device according to claim 5 is characterized in that: A connecting boss is provided at the upper end of the connecting drill rod, the connecting boss is threadedly connected to the second mounting groove, and the lower end of the second medium channel is located above the top surface of the connecting boss.

7. The self-sealing and in-hole desorption coal seam sampling device according to claim 6 is characterized in that: The connecting drill rod is provided with a third medium channel, the third medium channel penetrates the connecting drill rod along the axial direction, and the third medium channel is communicated with the second medium channel.

8. The self-sealing and in-hole desorption coal seam sampling device according to claim 5 is characterized in that: The lower end of the connecting drill rod is provided with a threaded connection hole coaxial with the third medium channel.

9. A coal seam sampling system capable of self-sealing and in-hole desorption, characterized in that: It comprises a self-sealing and in-hole desorbing coal seam sampling device, a pressure pump and a gas desorber as described in any one of claims 1 to 7, wherein the gas desorber is connected to a desorption channel in the coal seam sampling device, the pressure pump is connected to an expansion channel in the coal seam sampling device, a desorption control valve is arranged on the connecting pipe between the gas desorber and the coal seam sampling device, and a liquid injection control valve is arranged on the connecting pipe between the pressure pump and the coal seam sampling device.

10. A coal seam sampling method capable of self-sealing and in-hole desorption, characterized in that: The coal seam sampling system capable of self-sealing and in-hole desorption as claimed in claim 9 is adopted, and the coal seam sampling method comprises: Step S101, invert the main drill bit, align the auxiliary drill bit with the pin hole of the main drill bit for connection, and connect the core tube to the main drill bit; Step S102, injecting liquid into the expansion capsule through the expansion channel to expand the expansion capsule and squeeze the auxiliary drill bit onto the main drill bit; injecting gas into the cavity below the expansion capsule through the desorption channel to confirm the air tightness of the coal seam sampling device; Step S103, after the coal seam sampling device is depressurized and disassembled, it is taken underground for reassembly, and after the core tube of the coal seam sampling device is connected to the drilling rig, a hole is drilled; Step S104, in response to the coal seam sampling device reaching the preset coring position, the expansion capsule is depressurized, the expansion capsule shrinks to the original position, and the auxiliary drill bit falls under the action of its own weight; Step S105, in response to the coal blocks in the coal sample compartment reaching 1 / 3 to 1 / 2 of its volume, coring is completed and drilling is stopped; Step S106, injecting liquid through the expansion channel and maintaining the pressure in the expansion capsule not less than 5 MPa, so that the expansion capsule expands and seals the coal sample compartment; and simultaneously starting to desorb the coal sample in the coal sample compartment through the desorption channel; Step S107: During the desorption process of the coal sample in the coal sample compartment, synchronous drilling can be performed.

Images