Radius of investigation and impact of inter-porosity flow in naturally-fractured reservoirs

The radius of investigation (ROI) is an essential parameter in many reservoir engineering applications. Inconsistencies and ambiguities still exist between different ROI evaluation methods, especially for the dual-porosity (DP) system representing naturally fractured reservoirs. This paper revisited impact inter-porosity flow DP presented equations early late periods based on Laplace space solution Warren-Root model. A new comprehensive expression derived which accounts both storativity ratio (ω) coefficient (λ). method this reveals that log-log plot vs. time models exhibits two parallel straight lines linked by a smooth transition curve. distance these dependent ω, intermediate period highly value λ. equation can degenerate to similar formula single-porosity periods. Comparison analysis with other approaches conducted validation realized analytical numerical matching.