An integrated approach to characterize hydraulic fracturing-induced seismicity in shale reservoirs
Date
2021-10
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
In this study, an integrated approach of geology, geophysics, geomechanics and hydrodynamics is developed to characterize the hydraulic fracturing-induced seismicity in unconventional shale reservoirs. Firstly, a structural model including the faults and surfaces is developed by the multi-component 3D seismic interpretation. The local structure attributes analysis, and ant-tracking technique are then applied to identify the pre-existing faults and fractures distribution, where their distributions are calibrated by focal mechanism inversion of the mainshock events. Subsequently, a 3D geomechanical model is built, which incorporates the rock mechanics and in-situ stress regime into the structure model. Additionally, the hydraulic fracturing processes are simulated and hydraulic fractures geometry and fluid pressure distribution within the hydraulic fractures are estimated by history matching the net pressure. Finally, the fluid flow in hydraulic fractures is coupled with the geomechanical model to characterize the pore pressure diffusion and poroelastic stress perturbation that causes the fault to slip. As the field cases, the Mw 3.6 and Mw 4.1 induced seismicity near the Crooked Lake region are investigated to evaluate the applicability of the integrated approach. Moreover, the Mw 3.2 case and Mw 4.18 cases are analyzed to explore the controlling factors of hydraulic fracturing-induced seismicity in Western Canada. Based on eight field cases in Fox Creek, the susceptibility of hydraulic fracturing-induced seismicity towards fracturing stimulations are evaluated and potential mitigation strategies are proposed to reduce future seismicity risks. Finally, a comprehensive machine-learning approach is proposed to evaluate the susceptibility and mitigate the risks of hydraulically induced seismicity, as well as forecast the shale gas production via the integration of geological, geomechanical and operational factors in Fox Creek.
Description
Keywords
Induced Seismicity, Hydraulic Fracturing, Triggering Mechanism, Controlling Factors, Mitigation Strategy
Citation
Gang, H. (2021). An integrated approach to characterize hydraulic fracturing-induced seismicity in shale reservoirs (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.