Foam drainage and gas extraction device and method for coal mine underground water-bearing coal seam downward drilled hole

Abstract

The invention belongs to the field of gas extraction of coal mine underground coal seams, and relates to a foam drainage and gas extraction device and method for a coal mine underground water-bearingcoal seam downward drilled hole. The foam drainage and gas extraction device comprises an antipriming pipe arranged in the downward drilled hole; one end, far away from the downward drilled hole, of the antipriming pipe is connected with an extraction pipe; the extraction pipe communicates with a defoaming box; a gas extraction pipe is further connected onto the defoaming box and communicates witha gas extraction system; the foam drainage and gas extraction device further comprises a round steel pipe arranged in the downward drilled hole one end, far away from the downward drilled hole, of the round steel pipe is connected with an automatic foam drainage rod jetting device in a matched manner; the automatic foam drainage rod jetting device comprises a jetting gun connected with the roundsteel pipe and used for throwing foam drainage rods; the jetting gun is connected with a central processing unit through a connecting wire; and the automatic foam drainage rod jetting device further comprises an intelligent gate valve arranged on the jetting gun. According to the foam drainage and gas extraction device and method, through reaction of the foam drainage rods with water, foam drainage is performed on the underground water-bearing coal seam downward drilled hole economically and efficiently, and coal seam gas extraction is facilitated.

Description

technical field [0001] The invention belongs to the field of underground coal seam gas extraction in coal mines, and relates to a foam drainage and air extraction device and method for downward drilling of water-bearing coal seams in coal mines. Background technique [0002] In the process of drilling gas drainage in the underground water-bearing coal seam, there are construction water accumulation and coal seam water gushing problems, which will have a great impact on coal seam gas drainage, resulting in poor gas drainage effect. If the energy of the coal seam gas is large enough, the water in the downhole will be brought out of the orifice by the push and agitation of the updraft; if the energy of the coal seam gas itself is not enough to bring the water out of the hole, Due to the slippage effect, the accumulated water will gradually accumulate at the bottom of the borehole during the lift of the coal seam gas flow. With the accumulation of a period of time, these liquids...

AI Technical Summary

Problems solved by technology

[0002] In the process of underground gas drainage in the underground water-bearing coal seam, there are problems of construction water accumulation and coal seam water gushing, which will have a great impact on coal seam gas drainage, resulting in poor gas drainage effect

If the energy of the coal seam gas is large enough, the accumulated water in the downward borehole will be brought out of the orifice under the push and stirring of the updraft; if the energy of the coal seam gas itself is not enough to bring out the accumulated water in the hole, Due to the slippage effect, the accumulated water will gradually accumulate in the bottom area of ​​the borehole during the lifting of the gas flow in the coal seam. After a period of accumulation, these liquids will gather at the bottom of the hole and form a liquid column, which will generate additional damage to the coal seam gas. Hydrostatic back pressure leads to a continuous decline in coal seam gas drainage capacity, which has a serious impact on the coal seam gas drainage effect of downhole drilling, and in more serious cases, it will cause downhole drainage drilling to be flooded and stop production or even make the hole scrapped

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