A Rapid Method to Evaluate Triangular Patterns in Ultra-Low Permeability Fault-Block Oilfields

Considering the geometry of well patterns and the nonlinear features of fluids flow, the calculation formula of Effective Development Coefficient (EDC for short) for triangular patterns in ultra-low permeability fault-block oilfields was deduced by applying the stream-tube integral method. The influences of pressure difference, pattern geometry and threshold pressure gradient on EDC were analyzed. The analyses indicated that for ultra-low permeability fault-block oilfields the optimal pattern shape is isosceles/pseudo isosceles triangle. Increasing pressure difference is an effective measure to improve the development effect for relatively high permeability oilfields while reducing well spacing is effective for relatively low ones. This research provides a rapid method to evaluate triangular patterns in ultra-low permeability fault-block oilfields.