Effect of Natural Fractures on Shale Gas Reservoir Reconstruction

Abstract

Natural fractures have great influence on shale gas reservoir reconstruction. In order to find out the law of influence, comprehensive analysis of the characteristics of geological natural fracture and fracturing fracture before fracturing is carried out. Firstly, natural cracks are identified by using coherence and maximum relief attributes of ground seismic data. Secondly, the characteristics of hydraulic fracturing cracks and the response characteristics of natural cracks are analyzed by using the results of microseismic monitoring and positioning and the data of hydraulic fracturing construction. Finally, the influence of natural fracture on the effect of fracturing reconstruction is summarized. The results show that the response characteristics of natural cracks predicted by surface earthquakes are different in the results of microseismic monitoring. According to the response characteristics of natural cracks, they can be divided into active and inactive natural cracks. Combining with the fracturing data, it is found that both active and inactive natural cracks will affect the fracturing construction to varying degrees. Active natural fractures are prone to abnormal construction conditions such as sand plugging, casing deformation and fracturing fluid leakage. Non-active natural fractures play a role of stress shielding under certain conditions, which can affect the fracturing fracture morphology and the effect of fracturing reservoir reconstruction. The research results provide a basis for shale gas horizontal well trajectory optimization and adjustment of hydraulic pressure construction parameters.