Coupled Flow-Geomechanics Numerical Investigation of Microearthquakes and Planar Fracture Propagation in the Barnett Shale

Abstract

The purpose of this study is to investigate the effects of hydraulic fracturing stimulation for development of shale gas reservoirs. Particularly, the study considers the vertical planar fracture propagation and induced seismicity during hydraulic fracturing operations in the Barnett Shale. To this end, a sequentially implicit coupled-flow-geomechanics-geophysical simulator is used to generate a realistic model and to study the effects and potential issues surrounding hydraulic fracturing stimulating vertical and horizontal wells in the Barnett Shale. In addition, a sensitivity analysis is performed on the model to determine how the uncertainty of the model outputs can be apportioned to different sources of uncertainty in its inputs. From the results of the model combined with the literature, we obtain stable fracture propagation, having the limited vertical extent of the fractures. Furthermore, the model suggests that vertical extent of fractures is limited due to rock strength heterogeneity and variations of the stress field, while failure around cementing wells might be possible. Additionally, the magnitude of modelled the micro-earthquakes generated during hydraulic fracturing stimulation were not large enough to warrant safety concerns regarding seismicity, unless faults exist nearby. Finally, based on the outputs of the model, it is possible to couple a sequential flow-geomechanics simulator to model micro-earthquakes, fracture propagation, and stimulated reservoir area

    Similar works