Sensitivity analysis of hydraulic fracture geometry in shale gas reservoirs

The combination of horizontal drilling and multiple hydraulic fracturing has been widely used to stimulate shale gas reservoirs for economical gas production. Numerical simulation is a useful tool to optimize fracture half-length and spacing in a multistage fracturing design. We developed a methodology to use a commercial reservoir simulator to simulate production performance of shale gas reservoirs after fracturing. We verified our simulation method with the available field data from the Barnett Shale. In this work, we performed a sensitivity study of gas production for a shale gas well with different geometries of multiple transverse hydraulic fractures, in which fracturesʹ half-lengths vary. Hydraulic fractures are divided into two outer and inner fracture groups. The simulation results revealed that the outer fractures contribute more to gas production when fracture spacing is small due to the effect of fracture interference. Also, we studied the effects of fracture half-length and fracture spacing on gas production. This work can provide some insights into characterization of hydraulic fracture geometry on the basis of production data in shale gas reservoirs.