Influence factors and the application of cracking pressure in hydraulic fracturing
To determine the rational hydraulic fracturing timing and borehole locations,in terms of the surrounding stress distribution of hydraulic boreholes and roadway ground stress field category,borehole azimuth angle and inclined angle are defined as the main factors for hydraulic fracture cracking pressure.The influence of rock stratum cracking pressure during hydraulic fracturing is studied under different drilling parameters(azimuth angle,inclination angle)and different type crustal stress field,on the basis of roadway crustal stress field category.Based on roof 3D primary stress on-site measurement under mining at Wangpo Coal Mine,the roadway hydraulic fracturing timing and borehole layout of No.3308 transport roadway are determined,and the double sides fracturing scheme for the roadway is proposed.The stress and deformation monitoring results show that,the double sides fracturing scheme reduces the average peak stress by 52.9%compared to the conventional fracturing scheme;and reduces the subsidence of the roof by 14.0%,floor heave by 37.8%,and side-to-side convergence by 56.6%,compared with the original fracturing scheme.The surrounding rock of No.3308 transportation roadway has been effectively protected.
hydraulic fracturingborehole azimuthground stress fieldpressure relief plan
万方数据
维普
