A coal powder washing device in a wellbore

Abstract

A coal powder well washing device in a wellbore comprises a fixed seat, a connecting column is inserted in the middle of the fixed seat, a water channel is opened in the middle of the connecting column, a first drainage channel and a second drainage channel are opened on both sides of the water channel, a water injection pipe connected to the water channel, and a first drainage pipe and a second drainage pipe connected to the first drainage channel and the second drainage channel are arranged on the top side of the fixed seat; a well washing head is fixed at the bottom end of the connecting column; the bottom of the well washing head is closed, a water inlet hole is opened in the middle of the well washing head corresponding to the water channel, water outlet cavities connected to the water inlet hole are symmetrically opened on both sides of the water inlet hole, the well washing head has a first water outlet hole and a second water outlet hole corresponding to the first drainage channel and the second drainage channel, and a first water outlet cavity and a second water pumping cavity connected to the first water outlet hole and the second water outlet hole. The present invention aims to provide a well washing device that can be extended into a wellbore to wash coal powder and extract sewage from a coalbed methane wellbore.

Description

Technical Field

[0001] The invention relates to the technical field of coalbed methane mining, and in particular to a coal powder well washing device in a wellbore. Background Art

[0002] For coalbed methane extraction, it is necessary to extract it locally, and the current extraction strategy is generally only to extract the entire extraction borehole as a whole. During the extraction process or before extraction after drilling, the borehole is often blocked by coal powder, coal slag, etc. Due to the force problem during drilling, the blockage of the inner wall of the well is more serious. This leads to the blockage of the inner wall of the well due to coal powder during the later coalbed methane extraction, and it is impossible to achieve good coalbed methane extraction. Therefore, there is an urgent need for a well washing device that can reach into the wellbore to clean the coal powder in the coalbed methane wellbore and extract sewage. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a well washing device which can be extended into a wellbore to wash coal powder and extract sewage from the coalbed methane wellbore.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A coal powder well washing device in a wellbore, comprising a fixed seat, a connecting column inserted in the middle of the fixed seat, a water delivery channel opened in the middle of the connecting column, a first drainage channel and a second drainage channel opened on both sides of the water delivery channel of the connecting column, a water injection pipe connected to the water delivery channel, and a first drainage pipe and a second drainage pipe connected to the first drainage channel and the second drainage channel are arranged on the top side of the fixed seat; a well washing head is fixed to the bottom end of the connecting column; the bottom of the well washing head is closed, a water inlet hole is opened in the middle of the well washing head corresponding to the water delivery channel, and two symmetrical holes corresponding to the inlet hole are opened on both sides of the water inlet hole. A water outlet cavity connected to a water hole, a first water outlet hole and a second water outlet hole are provided in the well washing head corresponding to the first drainage channel and the second drainage channel, the well washing head is provided with a first pumping cavity which is on the same side as and connected to the first water outlet hole, and the well washing head has two second pumping cavities symmetrically opened and connected on both sides of the second water outlet hole; the aperture of the first water outlet hole is smaller than that of the second water outlet hole; the cross-section of the first pumping cavity is a fan-shaped opening facing outward, and the cross-section of the second pumping cavity is an arc-shaped concave toward the second water outlet hole, and at least three connecting cavities are provided between each second pumping cavity and the second water outlet hole.

[0006] Furthermore, the water outlet cavity is arranged obliquely on the well washing head.

[0007] Furthermore, the cross-section of the well washing head is elliptical.

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

[0009] 1. The horizontal cross-section of the well washing head in the present invention is an elliptical structure. When it is extended into the circular wellbore to wash the coal powder, it can form a wedge-shaped structure with the inner wall of the wellbore, providing a flow space with varying width of the water flow, which can change the flow velocity of the water flow between the inner wall of the wellbore and the well washing head. Compared with a water flow with a stable flow velocity, it is easier to discharge the coal powder, thereby improving the cleaning efficiency and thoroughness of the coal powder.

[0010] 2. The long axis of the elliptical well-washing head is provided with a water inlet, a first water outlet and a second water outlet. The end of the long axis of the well-washing head is provided with a fan-shaped first pumping cavity corresponding to the first water outlet, and two symmetrical arc-shaped second pumping cavities are provided corresponding to the second water outlet. Pumping cavities of different shapes can achieve different water flow rates and flow rates and well-washing pressures during cleaning, so that the coal powder on the inner wall of the wellbore can be washed by water flows of different flow rates and directions, which further facilitates the discharge of coal powder and improves the well-washing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention;

[0012] Figure 2 It is a structural schematic diagram of the well washing head in the present invention;

[0013] Figure 3 It is a schematic diagram of the structure of the connecting column in the present invention.

[0014] Description of reference numerals:

[0015] 1-wellbore, 2-connecting column, 3-fixed seat, 4-second drainage pipe, 5-water injection pipe, 6-first drainage pipe, 7-well washing head, 8-water inlet hole, 9-first water outlet hole, 10-second water outlet hole, 11-first pumping chamber, 12-second pumping chamber, 13-connecting chamber, 14-water outlet chamber, 21-water transmission channel, 22-first drainage channel, 23-second drainage channel. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0017] like Figures 1 to 3As shown, a coal powder well washing device in a wellbore comprises a fixed seat 3, a connecting column 2 is inserted in the middle of the fixed seat 3, a water channel 21 is opened in the middle of the connecting column 2, a first drainage channel 6 and a second drainage channel 4 are opened on both sides of the water channel 21 of the connecting column 2, a water injection pipe 5 connected to the water channel 21, and a first drainage pipe 6 and a second drainage pipe 4 connected to the first drainage channel 6 and the second drainage channel 4 are arranged on the top side of the fixed seat 3; a well washing head 7 is fixed to the bottom end of the connecting column 2; the bottom of the well washing head 7 is closed, a water inlet hole 8 is opened in the middle of the well washing head 7 corresponding to the water channel 21, and a first water outlet hole 9 and a second water outlet hole 10 are opened in the well washing head 7 corresponding to the first drainage channel 22 and the second drainage channel 23 ; The cross-section of the well washing head 7 is elliptical, and the water inlet hole 8, the first water outlet hole 9 and the second water outlet hole 10 are all arranged on the long axis of the elliptical surface. The well washing head 7 is symmetrically provided with water outlet cavities 14 connected to the water inlet hole 8 and inclinedly arranged on both sides of the water inlet hole 8; the well washing head 7 is provided with a first pumping cavity 11 on the same side as the first water outlet hole 9 and connected at the end on one side of the long axis, and the cross-section of the first pumping cavity 11 is a fan-shaped cavity with an opening facing outward; the well washing head 7 is symmetrically provided with two arc-shaped second pumping cavities 12 located on both sides of the second water outlet hole 10 and concave toward the second water outlet hole 10 at the end on the other side of the long axis, and at least three connecting cavities 13 are provided between each second pumping cavity 12 and the second water outlet hole 10.

[0018] Before using the present invention, a water pump for delivering washing water needs to be connected to the water injection pipe 5, and a self-priming pump for extracting sewage needs to be connected to the first drainage pipe 6 and the second drainage pipe 4. When flushing, the fixing seat 3 can be controlled to rotate outside the wellbore 1, and the well washing head 7 and the connecting column 2 can be extended into the wellbore 1 to clean the coal powder; or the length of the fixing seat 3 can be set to be larger than the diameter of the wellbore 1 in advance, and the fixing seat 3 can be placed on the wellbore 1 to allow water to flush by itself.

[0019] When cleaning the wellbore 1, the present invention injects water into the water injection pipe 5 through an external water pump, and the cleaning water flows out from the water outlet chambers 14 on both sides of the water inlet hole 8 through the water delivery channel 21. The water flowing to the inner wall of the wellbore 1 flows in the wedge-shaped cavity formed between the well washing head 7 and the inner wall of the wellbore 1. The wedge-shaped structure can change the flow rate and direction of the water, especially when the water pressure is insufficient, it can promote the flow and discharge of coal powder. After that, the water with coal powder is discharged through the first water outlet 9 and the second water outlet 10, and the wellbore 1 can be cleaned by rotating the fixing seat 3.

[0020] A first pumping chamber 11 connected to the first water outlet 9 and a second pumping chamber 12 connected to the second water outlet 10 are also provided on the axial side wall of the long axis of the well washing head 7. The positions of the first pumping chamber 11 and the second pumping chamber 12 are symmetrical relative to the center of the water inlet 8 and have different shapes, which can achieve different water flow rates and flow rates and well washing pressures during cleaning, promote the flow of coal powder with water, realize the discharge of coal powder, improve the well washing efficiency, and ensure the thoroughness of cleaning.

[0021] The aperture of the first water outlet hole 9 is smaller than that of the second water outlet hole 10, so that the amount of water discharged from the first water outlet hole 9 and the second water outlet hole 10 can be different, further promoting the change of water pressure in the wellbore 1, and facilitating the cleaning of coal powder.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A coal powder washing device in a wellbore, comprising a fixing seat, characterized in that: A connecting column is inserted in the middle of the fixing seat, a water channel is opened in the middle of the connecting column, a first drainage channel and a second drainage channel are opened on both sides of the water channel, a water injection pipe connected to the water channel, and a first drainage pipe and a second drainage pipe connected to the first drainage channel and the second drainage channel are arranged on the top side of the fixing seat; a well washing head is fixed to the bottom end of the connecting column; the bottom of the well washing head is closed, a water inlet hole is opened in the middle of the well washing head corresponding to the water channel, and water outlet cavities connected to the water inlet hole are symmetrically opened on both sides of the water inlet hole. The well washing head is provided with a first water outlet hole and a second water outlet hole corresponding to the first drainage channel and the second drainage channel, the well washing head is provided with a first water pumping cavity which is on the same side as and connected to the first water outlet hole, and the well washing head has two second water pumping cavities which are symmetrically provided and connected on both sides of the second water outlet hole; the aperture of the first water outlet hole is smaller than that of the second water outlet hole; the cross-section of the first water pumping cavity is a fan-shaped cavity opening outward, the cross-section of the second water pumping cavity is an arc-shaped cavity concave toward the second water outlet hole, and at least three connecting cavities are provided between each second water pumping cavity and the second water outlet hole.

2. A coal powder washing device in a wellbore according to claim 1, characterized in that: The water outlet cavity is arranged obliquely on the well washing head.

3. A coal powder washing device in a wellbore according to claim 1, characterized in that: The cross section of the well washing head is elliptical.

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