Effective Fracture Network Description Based on Microseism in China’s Hydraulic Fracturing Test Site

Summary During the construction of China’s first shale oil hydraulic fracturing test site (HFTS), downhole microseismic monitoring was implemented to systematically evaluate the scale and morphology of artificial fractures in the target well. Two adjacent horizontal wells were utilized as monitoring wells, with geophone arrays deployed via tractors. Post-fracturing, two coring wells were strategically positioned to capture subsurface fracture patterns, with their trajectories optimized using microseismic event density maps. Subsequent analysis integrated coring well interpretations with microseismic data to refine event screening criteria, enabling precise calculation of effective fracture network dimensions. Further enhancements to the regional microseismic interpretation model were achieved by incorporating 3D seismic attributes. Finally, hydraulic fracture network morphology was simulated, and expansion-influencing factors were analyzed using combined seismic and microseismic.