Research progress on the relationship between international hydraulic fracturing and earthquakes and suggestions for geological work

Hydraulic fracturing is a key technique for exploiting resources, such as tight gas, coal seam gas, shale oil and gas, hot dry rock, and so on.With the continuous large-scale industrial exploitation activities in China's main shale gas producing areas Sichuan Basin and its surrounding areas, and increasing workloads on hydraulic fracturing, the public has paid high attention to the issue of whether earthquakes could be induced by hydraulic fracturing. This paper reviews recent progress in studies of international hydraulic fracturing inducing earthquake risk and summarizes the effective risk prevention and control measures in the world. Results show that hydraulic fracturing can cause rock fracture by injecting fluid at high pressure, which will inevitably lead to microseismic activity; progress has been made in the mechanism of hydraulic fracturing-induced seismicity, which provides a basis for risk prevention and control; the influence of hydraulic fracturing on the seismicity above magnitude three is limited, and the records of artificial seismicity in areas with less natural earthquakes are also relatively less; the micro earthquake induced by hydraulic fracturing may help to release the accumulated crustal stress or energy and reduce the risk of large earthquakes; at present, the influence of hydraulic fracturing on earthquake has not been quantified. A series of effective prevention and control measures, such as engineering measures, legal systems, management measures, technical research and development, have been implemented to deal with the seismic risk caused by hydraulic fracturing. We propose some suggestions for resources development of shale oil and gas and dry hot rock in China: strengthen the investigation and evaluation of fault structure, and control the hydraulic fracturing at a certain distance from the fault; reinforce microseismic monitoring and carry out seismic hazard assessment of hydraulic fracturing; enhancing in scientific research on key scientific issues and increasing the publicity of public science.