Doubling Model for Lower Permeability Formation with Hydraulic Fracture

摘要

A fluid flow doubling model has been built for low-permeability formation and hydraulic fracture based on non-Darcy pressure propagation and fluid flow velocity difference in both matrix and fracture. A cross-flow rate model between facture and formation is derived from submerged fluid flooded in a rock grid matrix. It will be more convenient to describe the time-varying fracture conductivity than banded heterogeneous grids with higher permeability. A numerical model was derived based on a finite difference scheme for calculation, and a fractured well has been applied for productivity comparison with different models. It has been shown that pressure distribution in the fracture is weakly nonlinear because of cross flow, and a doubling model is more consistent with field production data. There exists a greater productivity difference in the previous production period for constant fracture conductivity and in the later part for banded heterogeneous model result from weakening performance difference between fracture and matrix. This article presents a practical model to evaluate the productivity of a fractured well.