Pressure Analysis of a Well with an Inclined Asymmetric Hydraulic Fracture Using Type Curves

摘要

Hydraulic fracturing is an effective well stimulation technique which is introduced in the 1950s and widely used in the oil and gas industry. Most of the works about hydraulic fracturing assumed that the fracture is symmetric and either vertical or horizontal. But, several field and laboratory observations show very complex fractures, inclined, multi-segmented, asymmetric, and multiple fractures. The purpose of this study is to investigate the pressure behaviour of a uniform flux hydraulic fracture which is both inclined and asymmetric. This objective is achieved by using transient pressure and pressure derivative plots. Three cases are investigated; (a) the fracture is asymmetric only along the horizontal direction (X-axis), (b) the fracture is asymmetric only along the lateral direction (Y-axis), and (c ) the fracture is asymmetric along both horizontal and lateral directions. Three flow regimes, Linear Flow Regime, Early-Radial Flow Regime, and Pseudo-Radial Flow Regime are observed when the asymmetry is not significant and for small θ_w and h_D . As the asymmetry increases the behaviour the fracture also shows changes. For a fracture with high asymmetry, Bi-radial Flow Regime is observed in addition to the above flow regimes. As the asymmetry becomes significant the uniform flux fracture solution shows similar behaviour to infinite conductivity fracture.