Pressure characteristics and performance of multi-stage fractured horizontal well in shale gas reservoirs with coupled flow and geomechanics

Multi-stage hydraulic fracturing is a crucial well completion strategy in unconventional reservoirs to improve hydrocarbon production. Reservoir performance and pressure characterization in multi-stage fracture development considering elastic rock mechanics are not systematically discussed in the literature. This work considers effects of elastic rock mechanics and hydraulic fractures in unconventional reservoir development scenarios using a numerical model with coupled fluid flow and geomechanics. A fully coupled flow and geomechanics model based on finite element method is introduced to analyze shale gas flow and corresponding pressure distribution in unconventional reservoirs. The model is validated with an analytical solution and history matched with field data. Furthermore, effects of rock mechanics, elastic properties, and hydraulic fracture geometry on reservoir performance and pressure distribution are studied using the fully coupled numerical model. Pressure distribution and reservoir performance in terms of production rates of these scenarios are analyzed. It is found that consideration of elastic rock mechanics decreases the hydrocarbon production rates and alters the pressure distribution in the unconventional reservoir. Rock mechanical properties and fracture spacing/length also affect flow rates and pressure. Fracture spacing, fracture length, and Young's modulus have the greatest effect on hydrocarbon production rates. Effects of elastic rock mechanics are most significant at central areas of the fractured region, while such effects are less significant at far ends of the horizontal wellbore. This work incorporates full geomechanics with a flow model to understand reservoir performance and pressure characterization in multi-stage hydraulic fracture development scenarios and quantifies effects of geomechanics and effects of various parameters in unconventional development scenarios.