Estimation of principal stress direction in geothermal reservoir using induced microseismic events during hydraulic stimulation

Abstract

In geothermal development, fluid is injected into subsurface fractures in reservoirs to improve productivity. At that time, understanding tectonic stress is important to estimate the portion where the permeability is improved. Tectonic stress can be measured in a borehole, but it requires drilling of the borehole, and the measurement in the deep borehole is costly and time-consuming. In this presentation, the tectonic stress measurement method using induced AE (Acoustic Emission) is introduced, where fracture planes are estimated from accurately estimated AE source distribution and the estimated possible slip directions of the fracture planes.