Quantifying reservoir connectivity, in-place volumes, and drainage-area pressures during primary depletion

This study presents an analytical formulation for multiple wells when production interference sets in amongst the wells, including the outer boundaries. This analytical solution estimates the connected pore-volume associated with each well, leading to average-reservoir pressure, and identifies the absence or existence of reservoir continuity. Only flowing bottomhole pressure (BHP) and rate data are needed for the analysis; the knowledge of reservoir geometry or shape factor and average-reservoir pressure is not required. Streamline simulations have aided generation of synthetic cases involving different heterogeneity settings. The new analytical model corroborates the results of those flow simulations. Synthetic examples validate the proposed approach, whereas a field example verifies the notion presented in this study. ► New analytical solutions offered for multiple wells during primary depletion. ► Drainage volume, drainage-area pressure, and well-to-well connectivity assessed. ► Streamline-simulation generated examples verified the proposed method. ► A field example validated the proposed approach.