Feeding method and device for hole protecting pipe for soft coal seam gas extraction hole

Abstract

The invention relates to a feeding method for a hole protecting pipe for a soft coal seam gas extraction hole. The feeding method is characterized in that an epoxy resin adhesive is used for filling sieve pores of the hole protecting pipe before the hole protecting pipe is fed into a drill hole, air with a certain pressure is pressed into the hole protecting pipe in the process of feeding the hole protecting pipe into the drill hole, the air flows into the drill hole through a vent hole arranged at the top end of the hole protecting pipe, and high-speed air currents discharge coal dusts from an orifice along the hole protecting pipe and a gap of the wall of the drill hole. After the hole protecting pipe is fed into the bottom of the hole, an epoxy resin adhesive dissolving agent is injected into inner holes of the hole protecting pipe for dissolving the expoxy resin adhesive in the sieve pores so as to extract the gas. The feeding method is convenient in operation, can overcome the problem that the hole protecting pipe is difficult to feed into the drill hole due to the residual coal dusts in the gas extraction hole and local hole collapse, and has the advantages of long feeding distance of the hole protecting pipe, thereby ensuring the higher concentration and high flow of the soft coal seam gas extraction. The feeding method is particularly suitable for soft coals and very soft coal seams in which hole collapse easily occurs.

Description

technical field

[0001] The invention relates to a method and a device for feeding a hole-protecting pipe into a gas extraction hole in a coal seam, in particular to a method and a device for feeding a hole-protecting pipe into a gas drainage hole in a soft coal seam. Background technique

[0002] In my country, the proportion of soft coal seams is large and the gas content is generally high, and the collapse of soft coal seams is the main factor restricting gas extraction. At present, the measures to prevent hole collapse in soft coal seams are mainly to feed the hole protection pipe into the gas drainage hole (the hole protection pipe adopts screen pipe). However, due to factors such as soft and hard stratification of coal seams, deep high ground stress, and soft coal rheology, gas drainage drilling holes in soft coal seams will have different degrees of residual coal debris after the hole is formed, and it is easy to cause local coal dust in a short period of time. Deform...

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