Low-temperature while-drilling coal seam gas content fixed-point sampling device

Abstract

The utility model discloses a low-temperature while-drilling coal seam gas content fixed-point sampling device which comprises a coring pipe, the coring pipe is a cylindrical cavity, the cylindrical cavity is a coring pipe inner cavity, a coring pipe opening is formed in an opening in one end of the coring pipe, the coring pipe is in threaded connection with a coring drill bit through the coring pipe opening, and a connector is arranged at the end, away from the coring drill bit, of the coring pipe. A powerful return spring is installed at the end, close to the connector, of an inner cavity of the coring pipe and connected with a round blocking piece, and a refrigerant adding opening is formed in the side, close to the connector, in the inner cavity of the coring pipe. According to the low-temperature while-drilling coal seam gas content fixed-point sampling device, heat generated by friction between the pipe wall of the coring pipe and the coal wall and heat generated by drill bit cuttings are prevented from being transmitted to the coring pipe, the coal sample deterioration and the gas loss amount are reduced, the purity of the obtained coal sample is high, and the coal seam gas content measurement accuracy is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal seam gas content determination, and in particular relates to a low-temperature while-drilling coal seam gas content fixed-point sampling device. Background Art

[0002] With the depletion of my country's shallow coal resources, the depth of coal seam mining has increased year by year. At the same time, the difficulty of gas disaster management has also increased. Scientific and accurate measurement of coal seam gas content can effectively ensure the personal safety of workers and safe and efficient mining of mines.

[0003] Gas content determination methods are divided into direct methods and indirect methods. Among them, the direct method is mainly the core tube method and the orifice sampling method. The error generated mainly comes from the calculation of the loss during the sampling process. The core tube method has the following main problems: (1) Sampling takes a long time. The time from coal sample exposure to being placed in a sealed can usually exceeds 5 minutes, resulting in increased gas loss; (2) When the core tube is sent to the bottom of the hole, it generates heat due to friction with the hole wall, which will cause the collected coal sample to deteriorate and accelerate gas desorption; (3) The residual coal sample on the hole wall will enter the core tube, resulting in low purity of the obtained coal sample and serious "mixed sample" phenomenon. Utility Model Content

[0004] The utility model aims to provide a low-temperature coal seam gas content fixed-point sampling device while drilling, which solves the problems that the coal sample purity obtained by the existing gas content measuring device is not high and the coal seam gas content measuring accuracy is low.

[0005] The technical scheme adopted by the utility model is a low-temperature fixed-point sampling device for coal seam gas content while drilling, comprising a coring tube, the coring tube presents a cylindrical cavity, the cylindrical cavity is the inner cavity of the coring tube, one end of the coring tube is opened to set a coring tube mouth, the coring tube is threadedly connected to the coring drill bit through the coring tube mouth, a connecting head is set at the end of the coring tube away from the coring drill bit, a strong return spring is installed at one end of the inner cavity of the coring tube close to the connecting head, the strong return spring is connected to a circular baffle, and a refrigerant addition port is opened in the inner cavity of the coring tube close to the connecting head.

[0006] The utility model is also characterized in that:

[0007] An annular groove is radially arranged on the inner wall of the inner cavity of the core tube close to the connecting head, a reset spring is arranged in the annular groove, and a locking spring is connected to the reset spring.

[0008] A plurality of slag discharge holes are provided on the side wall where the end of the core drill bit is connected to the core tube.

[0009] The installation diameter of the circular baffle is the same as the inner diameter of the core tube, and the outer edge of the circular baffle is in close contact with the inner wall of the inner cavity of the core tube.

[0010] The coring drill bit and the coring tube are arranged coaxially.

[0011] The connector is connected to the drill pipe.

[0012] The beneficial effects of the utility model are as follows: the low-temperature fixed-point sampling device for coal seam gas content while drilling of the utility model ensures the purity of the obtained coal sample through the slag discharge hole, the circular baffle and the locking spring piece, and at the same time reduces the temperature increase of the core tube by adding refrigerant to the refrigerant addition port. The utility model combines the advantages of the core tube sampling method and the orifice sampling method, which can not only realize fixed-point sampling, but also realize the advantages of simple sampling method and convenient operation, slow down the oxidation and deterioration degree of coal sample and the gas desorption rate, and improve the accuracy of coal seam gas content determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model is a structural schematic diagram of a low-temperature coal seam gas content fixed-point sampling device while drilling.

[0014] In the figure, 1. core drill bit, 2. slag discharge hole, 3. circular baffle, 4. strong return spring, 5. locking spring, 6. core tube cavity, 7. refrigerant addition port, 8. connector. DETAILED DESCRIPTION

[0015] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0016] Example 1

[0017] The utility model provides a low-temperature coal seam gas content fixed-point sampling device while drilling, the structure of which is as follows: Figure 1 As shown, it includes a core tube, which has a cylindrical cavity, and the cylindrical cavity is the core tube inner cavity 6. A core tube opening is opened at one end of the core tube, and the core tube is threadedly connected to the coring drill bit 1 through the core tube opening. A connector 8 is arranged at the end of the core tube away from the coring drill bit 1, and a strong return spring 4 is installed at one end of the core tube inner cavity 6 close to the connector 8. The strong return spring 4 is connected to the circular baffle 3, and a refrigerant addition port 7 is opened on the side of the core tube inner cavity 6 close to the connector 8.

[0018] Example 2

[0019] The installation diameter of the circular baffle 3 is the same as the inner diameter of the core sampling tube. The outer edge of the circular baffle 3 is in close contact with the inner wall of the core sampling tube cavity 6. An annular groove is radially arranged on the inner wall of the core sampling tube cavity 6 close to the connector 8. A reset spring is arranged in the annular groove. The reset spring is connected to the locking spring 5. The cooperation of the locking spring 5, the reset spring and the annular groove realizes the automatic locking and automatic return effect of the circular baffle 3 without any additional interference.

[0020] Example 3

[0021] The coring drill bit 1 and the coring tube are arranged coaxially, a center hole is opened in the center of the coring drill bit 1, and the coal residue of the coring drill bit 1 is sealed in the coring drill bit 1, and a plurality of slag discharge holes 2 are opened at the side wall where the end of the coring drill bit 1 is connected to the coring tube. The connector 8 is connected to the drill pipe, and the coring drill bit 1 rotates with the drill pipe. The utility model has flexible steering, the positioning spring piece 5 is convenient and durable, and the installation and disassembly are simple.

[0022] The working principle of the low-temperature fixed-point sampling device for coal seam gas content while drilling provided by the utility model is as follows: when the coring tube is sent into the bottom of the hole, part of the residual coal on the wall of the borehole will enter the coring drill bit 1, and the residual coal entering the coring drill bit 1 will be thrown out through the slag discharge hole 2 by means of the centrifugal force of the rotation of the drill rod, and the circular baffle 3 is located at the mouth of the coring tube in the natural state of the strong return spring 4, and the circular baffle 3 blocks part of the coal sample that is not thrown out, and discharges the residual coal at the slag discharge hole 2 closest to the circular baffle 3, thereby reducing the residual coal on the wall of the borehole from entering the inner cavity 6 of the coring tube as much as possible, thereby improving the "purity" of the obtained coal sample.

[0023] The working process of the low-temperature coal seam gas content fixed-point sampling device provided by the utility model is as follows: before sampling, refrigerant is added to the core tube cavity 6 through the refrigerant adding port 7, and the refrigerant in the cavity of the core tube cavity 6 reduces the heat generated by the friction between the core tube wall and the coal wall and the heat generated by the drill bit cutting the coal body and is conducted to the core tube wall; when in use, when the borehole reaches the predetermined sampling depth, the ordinary drill bit is replaced with the low-temperature coal seam gas content fixed-point sampling device while drilling, and the drill rod applies a force for the core drill bit 1 to cut the coal body and drill, so as to push the circular baffle 3 to move toward the bottom of the core tube cavity 6, and the circular baffle 3 moves to the position of the locking spring piece 5 and is fixed, and the circular baffle 3 no longer moves toward the core tube mouth.

[0024] The low-temperature fixed-point sampling device for coal seam gas content while drilling proposed in this embodiment adds refrigerant to the inner cavity 6 of the core tube through the refrigerant adding port 7, fully utilizes the space, reduces the heat generated by the friction between the core tube wall and the coal wall and the heat generated by the drill bit cuttings and coal body to the core tube wall; compared with traditional core tube sampling and orifice sampling, the utility model improves the purity of the obtained coal sample and reduces the temperature generated by the friction between the core tube and the coal wall.

Claims

1. Low-temperature coal seam gas content fixed-point sampling device while drilling, characterized in that: The invention comprises a coring tube, which is a cylindrical cavity, the cylindrical cavity is an inner cavity (6) of the coring tube, one end of the coring tube is opened to provide a coring tube opening, the coring tube is threadedly connected to a coring drill bit (1) through the coring tube opening, a connector (8) is provided at one end of the coring tube away from the coring drill bit (1), a strong return spring (4) is installed at one end of the inner cavity (6) of the coring tube close to the connector (8), the strong return spring (4) is connected to a circular baffle (3), and a refrigerant addition port (7) is provided in the inner cavity (6) of the coring tube close to the connector (8).

2. The low-temperature coal seam gas content fixed-point sampling device while drilling according to claim 1 is characterized in that: An annular groove is radially arranged on the inner wall of the core tube inner cavity (6) close to the connector (8), a reset spring is arranged in the annular groove, and a locking spring (5) is connected to the reset spring.

3. The low-temperature coal seam gas content fixed-point sampling device while drilling according to claim 2 is characterized in that: A plurality of slag discharge holes (2) are provided at the side wall where the end of the coring drill bit (1) is connected to the coring tube.

4. The low-temperature coal seam gas content fixed-point sampling device while drilling according to claim 3 is characterized in that: The installation diameter of the circular baffle (3) is the same as the inner diameter of the core tube, and the outer edge of the circular baffle (3) is in close contact with the inner wall of the inner cavity (6) of the core tube.

5. The low-temperature coal seam gas content fixed-point sampling device while drilling according to claim 4 is characterized in that: The coring drill bit (1) and the coring tube are arranged coaxially.

6. The low-temperature coal seam gas content fixed-point sampling device while drilling according to claim 5 is characterized in that: The connecting head (8) is connected to the drill pipe.

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