Simulation of the Production Performance of Fractured Horizontal Wells in Shale Gas Reservoirs Considering the Complex Fracture Shape

Hydraulic fractures and natural fractures constitute the gas flow channels of fractured horizontal wells in shale gas reservoirs. Their shape and structural characteristics determine the production of horizontal wells and reservoir pressure propagation. To study the influence of hydraulic fractures and natural fractures on reservoir production performance at different degrees of complexity, a method was proposed to construct and simulate hydraulic fractures and natural fractures with complex shapes based on an embedded discrete fracture model, and the finite volume method was used to solve the model. On this basis, the effects of hydraulic fracture complexity and natural fracture connectivity on the production performance of fractured horizontal wells are analyzed. The results show that when the natural fracture orientation is perpendicular to the pressure wave propagation direction, the natural fracture will form a local shielding effect on the pressure propagation. Better natural fracture connectivity leads to better seepage capacity of the complex fracture network. Under the same conditions, hydraulic fracture complexity is more controllable than natural fracture connectivity, and the contribution of hydraulic fracture complexity to horizontal well production is underestimated. Increasing the complexity of hydraulic fracture is the key to improve the effect of hydraulic fracturing. Combining ant body technology and microseismic monitoring data, the method proposed in this paper is applied in the Longmaxi shale formation to obtain the history matching with the gas well production data and predict the estimated ultimate recovery.

Automated summary

Hydraulic fractures and natural fractures have significant impacts on the production performance of fractured horizontal wells in shale gas reservoirs. The complexity of hydraulic fractures is more controllable than the connectivity of natural fractures, and increasing the complexity of hydraulic fractures is key to improving hydraulic fracturing effectiveness.