Analytical well-test model for hydraulicly fractured wells with multiwell interference in double porosity gas reservoirs

Abstract

Interference resulting from infill wells in multiwell systems becomes a common issue in interpreting well tests data from hydraulicly fractured wells in tight carbonate gas reservoirs. Current single-well pressure transient approaches may falsely interpret well interferences as the composite reservoir or boundary effects, leading to significant errors in reservoir parameter estimation. Additionally, the most semi-analytical and numerical solutions used for fractured wells are computationally demanding and inconvenient to use. This work presents a novel and simple analytical well-test model for hydraulicly fractured wells with multiwell interference in double porosity gas reservoirs with significantly less computational time and effort than the existing methods. The analytical solution for a hydraulically fractured well with finite conductivity fracture in a multiwell system with well interference is presented based on the superposition principle, the early-time approximate solutions of trilinear flow and the infinite-conductivity fracture model. A systematic verification is conducted to ensure the validity of the presented solution. The solution is valid when the dimensionless fracture conductivity is greater than 1 (FcD>1) with ∼1% error in pressure and derivative. Furthermore, we offer a criterion of identifying well interference using the pressure derivative of the late-time approximation of the proposed analytical solution. Finally, a case study is conducted in the Sichuan Basin, indicating the proposed solution's applicability.