Seepage model and productivity prediction of fractured wells in shale gas reservoirs with discontinuous micro-fractures

A dual-porosity medium with micro-fractured spherical matrix blocks was achieved on the basis of the structure characteristics of nano-micro pores and micro-fractures in shale gas reservoirs. The Laplace space solution of the dimensionless bottom hole pressure of fractured well production was obtained in consideration of the seepage,diffusion and desorption mechanism of shale gas and applying the Laplace transform and the Stehfest numerical inversion. Type curves of dimensionless production were plotted and the influencing factors of the type curves were identified. The results show that the matrix surface improves gas transfer from the matrix medium to the fracture network due to matrix micro fractures. Increasing the permeability and length of micro fractures accelerate the productivity significantly.