Study on Underground Hydraulic Fracturing Technology for Soft Coal Seam with Low Permeability
LI Lei
LI Zhongjun
WU Wenbin
Abstract：In order to study the underground hydraulic fracturing technology of soft coal seam with low permeability, based on the site conditions of Panyi East Coal Mine of Huainan Mining Group, it was obtained from the analysis that the elastic modulus and Poisson′s ratio of coal were the main factors affecting the fracturing crack size and deciding the crack occurrence form according to the established fracturing crack size calculation model of the soft coal seam with low permeability; and through the analysis and calculation of the net pressure in coal fractures, the affecting factors on the fracturing pump injection pressure were also studied. It was obtained by theoretical calculation that the coal seam' s fracturing initial pressure was 24. 3 MPa in the test area and the designed pump injection pressure was 30. 2 MPa;the pressure error between fracturing test and calculation was only 3. 3%, which confirmed the feasibility of the theoretical calculation method. The field test results showed that the influence radius of hydraulic fracturing was as large as 40 m, and after fracturing the gas permeability of the coal seam and gas drainage effect were significantly improved, and the gas control cost was also greatly reduced.
Keywords：soft coal seam with low permeabilityunderground hydraulic fracturingfractured crackconstruction technologyfracturing effect
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 5-9 )