Hydraulic Fracturing-Induced Microseismicity Controlled by Rock Brittleness and Natural Fractures in Tongren, Guizhou, China

Abstract

Hydraulic fracturing-induced microseismicity has drawn public attention in recent years. However, understanding the behavior of the hydraulic fracture is limited due to complex relationship between the microseismicity and the various geological conditions. To further understand this question, we conducted a study to detect and locate hydraulic fracturing-induced microseismicity at a shale gas production site in Tongren, Guizhou, China. We investigate the relationship between their distribution and two important geological factors: the brittleness index of rocks and the distribution of natural fractures. With the aid of a 3D active seismic survey, we first calculate the brittleness index of rocks in the hydraulic fracturing region using Young’s modulus and Poisson’s ratio, compared with the locating result of fracturing-induced microseismicity shows the mostly events distributed in the area with higher brittleness index. We then delineate natural fractures using the Ant Tracking method of the 3D seismic attribute. The microseismic location is consistent with the region of the natural fractures. Based on our findings, we suggest the spatial distribution of induced microseismicity is highly controlled by the brittleness of rocks and the distribution of natural fractures in this region. This research provides insights into the factors controlling hydraulic fracturing-induced microseismicity and enhances our understanding of the complex interplay between geological conditions and the behavior of hydraulic fractures.