Multi-round compressed air deblocking method for coal bed gas well fracturing and blocking

Abstract

The invention relates to a deblocking method for coal bed gas well fracturing and powder blocking in the field of coal bed gas exploitation. The method includes adopting an air compressor to slowly inject compressed air from the ground into a shaft of a blocked coal bed gas well to form certain high pressure in the shaft and a coal bed, then opening a well opening discharge valve to quickly release high pressure gas in the shaft, so that blocking coal powder and sand in a fracturing crack will be loosened and move to the shaft with the compressed air and then return to the ground through a delocking pipe column. The process is repeated for multiple rounds to eliminate the well fracturing and coal powder blocking phenomenon, and the gas production will be restored. More importantly, the coal bed is not damaged, and high application value is achieved.

Description

Technical field [0001] The invention relates to the technical field of coalbed methane mining, and more specifically to a method for removing blockage of coal seam gas pressure fracturing blocked wells with multi-round compressed air. Background technique [0002] In the field of coalbed methane exploration and development, vertical wells and cluster wells are usually drilled through hydraulic fracturing, or horizontal wells are drilled through staged hydraulic fracturing, and various patterns of water that are not reconstructed through hydraulic fracturing are drilled in coal seams. Flat boreholes are used to increase the exposed area of ​​coal seams, and to achieve coal-bed methane extraction through drainage and pressure reduction. Drainage and depressurization gas extraction is through artificial lifting technology, usually pumping unit or screw pump to discharge the water in the wellbore to the ground (tubing drainage), the liquid level in the wellbore drops, and the bottom ...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the present invention provides a multi-round compressed air deblocking method for clogged coal seam gas fracturing wells, which overcomes the inability to dredge and unblock cracks that have been blocked by coal powder in the coal seams of fracturing wells, The lack of formation pressure causes the secondary blockage caused by the coal powder carried by the washing fluid into the coal seam, and solves the problem that the high-pressure nitrogen plugging removal method has a poor effect on coalbed methane plugging wells with a coal seam pressure deficit, high construction costs, and a lot of construction equipment. Problems, reduce construction costs, efficiently remove plugging wells with coal seam pressure deficit, achieve the goal of restoring or even increasing the gas production of plugged wells, and make most low-yielding coalbed methane wells have commercial exploitation value

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