Numerical analysis of gas production laws considering heterogeneous proppant distribution

Hydraulic fracturing is an effective treatment to enhance hydrocarbon recovery, such as shale gas. Proppant distribution is considered to be an important factor affecting fracture conductivity and cumulative gas production. In this paper, proppant flow simulation and gas production simulation were combined to numerically simulate the performance of partially propped fractures. The Eulerian Granular model was applied to simulate proppant migration and deposition in a 100-m-length fracture. The obtained proppant distribution data were extracted, converted, and inputted for gas production simulation in the in-house macroscopic reservoir simulator. The effects of various injection parameters on proppant distribution and cumulative gas production were investigated. Three types of proppant distribution patterns are concluded from dozens of cases with different pumping conditions. It was found that proppant distribution influences cumulative gas production a lot and the production is proportional to the locations of the proppant dune peak. The pressure distributions of the partially propped fracture observed from different views were compared and the influence of heterogeneous proppant distribution on pressure distribution was presented. Thus, combing the proppant flow simulation and gas production simulation can provide a more accurate prediction of pressure distribution and cumulative gas production for the fractured reservoir. Ignoring and simplifying the effects of proppant distribution or dune shapes in the fracture was not recommend. This work will expand the understanding of the difference in cumulative gas production from fractures with different proppant distributions. It helps optimize injection parameters and improve the well performance in the unconventional gas reservoir.