Author(s)

Hao Ma, Mingxing Gou, Lingxin Sun, Jinlong Liang

Corresponding Author

Jinlong Liang

ABSTRACT

The earthquakes induced by water injection are common at home and abroad. Some scholars have pointed out that water injection can directly cause or induce earthquakes. The relationship among water injection, earthquake, fracture and stress field have been studying. Based on the elastic callback theory, this paper described qualitatively and quantitatively the earthquake preparation processes induced by water injection into the salt wells in the Changning region in Sichuan, China. According to the earthquake induction mechanism established by Mohr-Coulomb criterion, the influence on the friction correlation coefficient and rock strength properties caused by imbalance of water injection into the salt wells was discussed, and the relationship between induced earthquake and salt well activities was established. A parameter model considering the influence factors of salt wells was introduced into the measurement of multiple seismic activity index.The spatio-temporal relationship between seismic activity index and salt well mining was obtained. Meanwhile, a Bayesian probability model for seismic risk assessment was established to assess the risk of the induced earthquakes. The results of this study are expected to provide a theoretical basis for other areas where water injection may induce earthquakes. It will provide a reference for the precaution of such earthquakes in the similar areas.

KEYWORDS

Water injection induced earthquake, seismic activity rate index, Bayesian probability