METHOD SEQUENTIALLY EMPLOYING ACETONE EROSION AND HYDRAULIC FRACTURING TECHNIQUES IN BOREHOLE TO INCREASE PERMEABILITY OF COAL SEAM

摘要

Disclosed is a method sequentially employing acetone erosion and hydraulic fracturing techniques in a borehole to increase permeability of a coal seam. The method employs an acetone solvent to perform an erosion operation on a coal seam, and new cracks are formed at the coal seam eroded by acetone. Next, a hydraulic fracturing operation is performed on the coal seam to facilitate formation of pores and cracks at the coal seam, thereby increasing permeability of the coal seam, and facilitating desorption and flow of gas in the coal seam. The method combines acetone erosion and hydraulic fracturing techniques to improve pore and crack structures of a coal seam, increase permeability of the coal seam and facilitate desorption and migration of gas, thereby enabling gas to be extracted from a coal seam effectively.