Hole collapse prevention screen pipe for gas extraction

Abstract

The utility model discloses an anti-sloughing hole sieve tube for gas extraction, which comprises a sieve tube, a positioning component is arranged on the upper side of the sieve tube, a resistance reducing component is arranged on the upper side of the sieve tube close to the positioning component, the positioning component comprises a tail tube sleeved on the upper side of the sieve tube, an internal thread I is arranged on the inner side of the tail tube, and an external thread II is arranged on the outer side of the tail tube. A head pipe is fixedly arranged at the upper end of the tail pipe, a spacer is fixedly arranged between the first internal thread and the head pipe, a convex ring is fixedly arranged on the outer side of the head pipe, four sets of expansion sections are fixedly arranged at the position, close to the outer side of the head pipe, of the upper end of the tail pipe, and upper clamping sleeves are fixedly arranged at the upper ends of the four sets of expansion sections. According to the anti-sloughing screen pipe for gas extraction, the purpose that the screen pipe can be rapidly put down by a single person is ensured, meanwhile, the friction force between the screen pipe and the wall of a drill hole is reduced, the diameter of the four sets of expansion sections is slightly larger than the diameter of the drill hole after the four sets of expansion sections are completely expanded, the wall of the drill hole is tightly jacked, the position of the screen pipe is fixed, and gas extraction work is stably conducted.

Description

TECHNICAL FIELD

[0001] The utility model relates to gas extraction technical field, especially in gas extraction prevents the screen pipe of hole collapse. BACKGROUND

[0002] The conventional means of gas control of the existing coal mine mainly adopts, through drilling in the upward part of the bottom extraction lane rock stratum to form a through layer drill hole, penetrates the coal seam, artificially creates a gas extraction channel. The gas in the coal seam flows to the drill hole under the action of pressure gradient, and the soft and broken coal seam is extremely prone to hole collapse and diameter reduction under the action of ground stress, which reduces the gas extraction efficiency of the drill hole and even leads to failure. In order to solve the problem, the coal mine underground site will lower the screen pipe into the drill hole after the drilling is completed, support and maintain the drill hole, prevent the broken coal seam from collapsing and blocking the gas extraction channel of the drill hole, and delay the damage and deformation of the coal and rock stratum around the drill hole wall caused by ground stress, meet the extraction time requirement of the drill hole design, and ensure that the gas control of the mine can meet the coal mining requirement. Moreover, the through layer drill hole of the site generally has a large inclination, which causes the screen pipe to slide downward under the action of gravity when the screen pipe is connected in the process of lowering the screen pipe into the drill hole, so that more personnel are needed for the screen pipe lowering operation. After the screen pipe lowering operation is completed, the screen pipe will also slide downward under the action of gravity due to the lack of fixing method, which increases the difficulty of subsequent hole sealing for gas extraction of the drill hole and reduces the site construction efficiency. CONTENT OF THE UTILITY MODEL

[0003] The main purpose of the utility model is to provide a gas extraction prevents the screen pipe of hole collapse, which can effectively solve the problems in the background art.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the utility model is as follows:

[0005] A gas extraction prevents the screen pipe of hole collapse, which comprises a screen pipe, a positioning assembly is arranged on the upper side of the screen pipe, a drag reduction assembly is arranged on the upper side of the screen pipe close to the positioning assembly, the positioning assembly comprises a tail pipe sleeved on the upper side of the screen pipe, an internal thread one is arranged on the inner side of the tail pipe, a head pipe is fixedly arranged on the upper end of the tail pipe, a partition is fixedly arranged between the internal thread one and the head pipe, a convex ring is fixedly arranged on the outer side of the head pipe, four groups of expansion sections are fixedly arranged on the outer side of the tail pipe close to the head pipe, an upper clamping sleeve is fixedly arranged on the upper end of the four groups of expansion sections, and a concave ring is formed in the inner wall of the upper clamping sleeve.

[0006] Preferably, a plurality of screen holes are formed in the outer side of the screen pipe, a female joint is arranged on the inner bottom of the screen pipe, a male joint is fixedly arranged on the upper end of the screen pipe, and an external thread is arranged on the outer side of the screen pipe close to the male joint.

[0007] Preferably, the drag reduction assembly comprises a drag reduction sleeve sleeved outside the screen pipe near the external thread position, the inner wall of the drag reduction sleeve is provided with internal threads two, a plurality of groups of ball cabins are opened in the inner part of the periphery of the drag reduction sleeve, the inner side of the ball cabin is movably provided with a ball, the outer side of the drag reduction sleeve is covered with a cabin cover plate, and the cabin cover plate and the inner part of the drag reduction sleeve are inserted with two groups of plastic screws.

[0008] Preferably, the head pipe is matched with the inner space of the upper sleeve, the partition plate separates the inner side of the head pipe from the tail pipe, the convex ring is matched with the concave ring, the expansion section has plasticity, and the middle position of the expansion section is arranged as a stress variable node.

[0009] Preferably, the convex joint is matched with the concave joint, the length of the internal threads one and the threads.

[0010] Preferably, the internal threads two of the inner side of the drag reduction sleeve are threadedly connected with the external threads, the ball movably passes through the inner side position of the cabin cover plate, and the plastic screws fix the cabin cover plate outside the ball cabin.

[0011] Compared with the prior art, the drag reduction assembly has the following beneficial effects:

[0012] 1. One end of the positioning assembly is inserted into the drilled hole, the ball exposed on the outer surface of the drag reduction assembly is in contact with the hole wall, the sliding friction between the screen pipe and the hole wall is changed into rolling friction when the screen pipe is in contact with the hole wall, the convex joint of the next group of screen pipes is threadedly connected with the concave joint, the sharply increased friction force caused by the continuous extension of the screen pipes is avoided, and the purpose that the screen pipe is quickly lowered by single-person operation is ensured.

[0013] 2. When the positioning assembly reaches the hole bottom, the screen pipe is continuously lowered into the hole, the screen pipe applies pressure to the tail pipe and the head pipe, the four expansion sections are extruded, the middle stress variable node of the expansion section is expanded outward to form a semicircular arch structure when the expansion section is extruded, the outer surface of the head pipe is designed with a convex ring which enters the upper sleeve and is matched with the concave ring, the head pipe and the upper sleeve are fixedly connected, and the diameters of the four expansion sections are slightly larger than the diameter of the hole after the four expansion sections are completely expanded, so that the hole wall is tightly pressed, the position of the screen pipe is fixed, and the gas extraction work in the hole is stabilized.

[0014] 3. After the screen pipe is lowered, the hole is sealed, the gas extraction pipeline in the roadway is connected with the screen pipe, the gas in the coal seam flows to the hole under the action of the pressure gradient, enters the screen pipe through the screen hole, and finally is transported to the ground for storage under the action of the negative pressure drainage. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1The utility model discloses a whole structure schematic diagram of the screen pipe of preventing hole collapse is used to gas extraction,

[0016] Figure 2 The utility model discloses a positioning assembly structure schematic diagram of the screen pipe of preventing hole collapse is used to gas extraction,

[0017] Figure 3 The utility model discloses the stress structure schematic diagram of the expansion section of the screen pipe of preventing hole collapse is used to gas extraction,

[0018] Figure 4 The utility model discloses the head pipe upper sleeve structure schematic diagram of the screen pipe of preventing hole collapse is used to gas extraction,

[0019] Figure 5 The utility model discloses a screen pipe structure schematic diagram of the screen pipe of preventing hole collapse is used to gas extraction,

[0020] Figure 6 The utility model discloses the drag reduction assembly structure schematic diagram of the screen pipe of preventing hole collapse is used to gas extraction.

[0021] In the drawing: 1, screen pipe;2, positioning assembly;21, tail pipe;22, internal thread one;23, head pipe;24, spacer;25, convex ring;26, expansion section;27, upper sleeve;28, concave ring;3, drag reduction assembly;31, drag reduction sleeve;32, internal thread two;33, ball cabin;34, ball;35, cabin cover plate;36, plastic screw;4, screen hole;5, female joint;6, male joint;7, external thread. DETAILED DESCRIPTION

[0022] In order to make the technical means, creation features, purposes and effects of the utility model easy to understand, the utility model is further described below in combination with specific embodiments.

[0023] As Figures 1-6 Shown, a kind of screen pipe of preventing hole collapse is used to gas extraction, including screen pipe 1, the upper side of screen pipe 1 is provided with positioning assembly 2, screen pipe 1 upper side is close to the position of positioning assembly 2 and is provided with drag reduction assembly 3, positioning assembly 2 includes the tail pipe 21 of sleeve on the upper side of screen pipe 1, the inner side of tail pipe 21 is provided with internal thread one 22, the upper end of tail pipe 21 is fixedly provided with head pipe 23, internal thread one 22 and head pipe 23 between fixedly provided with spacer 24, the outer side of head pipe 23 is fixedly provided with convex ring 25, the outer side of tail pipe 21 upper end close to head pipe 23 is fixedly provided with four groups of expansion section 26, the upper end of four groups of expansion section 26 is fixedly provided with upper sleeve 27, recess ring 28 is set on the inner wall of upper sleeve 27.

[0024] In this embodiment, the head tube 23 is matched with the internal space of the upper sleeve 27, the partition 24 separates the head tube 23 from the inside of the tail tube 21, the convex ring 25 is matched with the concave ring 28, the expansion section 26 has plasticity, and the middle position of the expansion section 26 is set as a force variable node.

[0025] Specifically, when the positioning assembly 2 reaches the bottom of the drilling hole, the screen pipe 1 continues to be lowered into the drilling hole, and the screen pipe 1 exerts pressure on the tail tube 21 and the head tube 23. The expansion sections 26 around are extruded, and when the expansion sections 26 are extruded, the middle force variable node expands outward to form a semicircular arch structure (as shown in Figure 3 ), at this time, the head tube 23 is designed with a circle of convex rings 25 entering the upper sleeve 27 and matching with the concave ring 28, and the head tube 23 and the upper sleeve 27 are fixedly connected. After the four expansion sections 26 are completely expanded, the diameters of the four expansion sections 26 are slightly larger than the diameter of the drilling hole, and the drilling hole wall is tightly pressed to fix the position of the screen pipe 1 and stabilize the gas extraction work in the hole.

[0026] In this embodiment, a plurality of screen holes 4 are formed on the outside of the screen pipe 1, a female connector 5 is arranged at the bottom of the inside of the screen pipe 1, a male connector 6 is fixedly arranged at the upper end of the screen pipe 1, an external thread 7 is arranged at the position close to the male connector 6 on the outside of the screen pipe 1, the male connector 6 is matched with the female connector 5 and the internal thread 22 in length and thread, and the screen pipe 1 and the male connector 6 are an integral structure.

[0027] Specifically, after the screen pipe 1 is lowered, the drilling hole is sealed, the gas extraction pipeline in the roadway is connected with the screen pipe 1, the gas in the coal seam flows to the drilling hole under the action of the pressure gradient, enters the screen pipe through the screen holes 4, and the gas in the roadway is finally transported to the ground for storage under the action of the negative pressure drainage.

[0028] In this embodiment, the drag reduction assembly 3 includes a drag reduction sleeve 31 sleeved on the outside of the screen pipe 1 close to the external thread 7, an internal thread 32 is arranged on the inner wall of the drag reduction sleeve 31, a plurality of ball cabins 33 are formed on the inside of the four peripheries of the drag reduction sleeve 31, ball balls 34 are movably arranged on the inside of the ball cabins 33, a cabin cover plate 35 covers the outside of the drag reduction sleeve 31, two groups of plastic screws 36 are inserted into the inside of the drag reduction sleeve 31 and the cabin cover plate 35, the internal thread 32 on the inside of the drag reduction sleeve 31 is threadedly connected with the external thread 7, the ball balls 34 movably pass through the inside of the cabin cover plate 35, and the plastic screws 36 fix the cabin cover plate 35 on the outside of the ball cabins 33.

[0029] Specifically, one end of the positioning assembly 2 is inserted into the drilled hole, the ball 34 exposed on the outer surface of the drag reduction assembly 3 is in contact with the hole wall, the sliding friction between the screen pipe 1 and the hole wall is changed into rolling friction when the screen pipe 1 is in contact with the hole wall, the male joint 6 of the next screen pipe 1 is threadedly connected with the female joint 5, the sharply increased friction force with the continuous extension of the screen pipe 1 is avoided, and the purpose that the screen pipe 1 is quickly lowered in single-person operation is ensured.

[0030] Working principle:

[0031] In use, one end of the positioning assembly 2 is inserted into the drilled hole, the ball 34 exposed on the outer surface of the drag reduction assembly 3 is in contact with the hole wall, the sliding friction between the screen pipe 1 and the hole wall is changed into rolling friction when the screen pipe 1 is in contact with the hole wall, the male joint 6 of the next screen pipe 1 is threadedly connected with the female joint 5, the sharply increased friction force with the continuous extension of the screen pipe 1 is avoided, and the purpose that the screen pipe 1 is quickly lowered in single-person operation is ensured; when the positioning assembly 2 reaches the hole bottom, the screen pipe 1 is continuously lowered into the hole, the screen pipe 1 exerts pressure on the tail pipe 21 and the head pipe 23, the four surrounding expansion sections 26 are extruded, the middle stress change nodes of the expansion sections 26 are outwardly expanded into semicircular arch structures (as shown in Figure 3 ), at this time, the head pipe 23 is designed with a ring of convex rings 25 which are matched with the concave rings 28 in the upper sleeve 27, the head pipe 23 is fixedly connected with the upper sleeve 27, and the diameters of the four expansion sections 26 are slightly larger than the diameter of the hole after the four expansion sections 26 are completely expanded, the four expansion sections 26 are tightly pressed against the hole wall, the position of the screen pipe 1 is fixed, and the gas extraction in the hole is stabilized; after the screen pipe 1 is lowered, the hole is sealed, the gas extraction pipeline in the roadway is connected with the screen pipe 1, the gas in the coal seam flows to the hole under the action of the pressure gradient, enters the screen pipe through the screen holes 4, and the gas in the roadway is finally transported to the ground for storage under the action of the negative pressure drainage.

[0032] The basic principle and main features of the utility model and the advantages of the utility model are shown and described. It should be understood by those skilled in the art that the utility model is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and the description in the specification are only used to illustrate the principle of the utility model, various changes and improvements can be made to the utility model without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model. The protection scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A gas extraction system using an anti-collapse perforated screen pipe, comprising a screen pipe (1), characterized in that: A positioning component (2) is provided on the upper side of the screen tube (1). A drag-reducing component (3) is provided on the upper side of the screen tube (1) near the positioning component (2). The positioning component (2) includes a tail tube (21) sleeved on the upper side of the screen tube (1). An internal thread (22) is provided on the inner side of the tail tube (21). A head tube (23) is fixedly provided at the upper end of the tail tube (21). A partition (24) is fixedly provided between the internal thread (22) and the head tube (23). A convex ring (25) is fixedly provided on the outer side of the head tube (23). Four sets of expansion sections (26) are fixedly provided at the upper end of the tail tube (21) near the outer side of the head tube (23). An upper sleeve (27) is fixedly provided at the upper end of the four sets of expansion sections (26). A concave ring (28) is provided on the inner wall of the upper sleeve (27).

2. The gas extraction system using an anti-collapse perforated screen pipe according to claim 1, characterized in that: The screen tube (1) has several sets of screen holes (4) on its outer side. The bottom of the inner side of the screen tube (1) is provided with a concave joint (5). The upper end of the screen tube (1) is fixedly provided with a convex joint (6). The outer side of the screen tube (1) is provided with an external thread (7) near the convex joint (6).

3. A gas extraction system using an anti-collapse perforated screen pipe according to claim 1, characterized in that: The drag reduction assembly (3) includes a drag reduction sleeve (31) fitted on the outside of the screen tube (1) near the external thread (7). The inner wall of the drag reduction sleeve (31) is provided with an internal thread (32). Several sets of ball chambers (33) are opened inside the circumference of the drag reduction sleeve (31). Ball balls (34) are movably arranged inside the ball chambers (33). The outer side of the drag reduction sleeve (31) is covered with a chamber cover plate (35). Two sets of plastic screws (36) are inserted into the chamber cover plate (35) and the drag reduction sleeve (31).

4. A gas extraction system using an anti-collapse perforated screen pipe according to claim 1, characterized in that: The head tube (23) is adapted to the internal space of the upper sleeve (27), the partition (24) separates the head tube (23) from the inner side of the tail tube (21), the convex ring (25) is adapted to the concave ring (28), the expansion section (26) is plastic, and the middle position of the expansion section (26) is set as a force-bearing variable node.

5. A gas extraction system using an anti-collapse perforated screen pipe according to claim 2, characterized in that: The convex joint (6) and the concave joint (5), the length and thread of the internal thread (22) are compatible, and the screen tube (1) and the convex joint (6) are an integral structure.

6. A gas extraction system using an anti-collapse perforated screen pipe according to claim 3, characterized in that: The inner thread 2 (32) on the inner side of the drag-reducing sleeve (31) is threadedly connected to the outer thread (7), the ball (34) moves through the inner side of the cover plate (35), and the plastic screw (36) fixes the cover plate (35) to the outside of the ball chamber (33).

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