Interference Analysis in Reservoirs with Bottom-Water Drive During Water Injection Processes Through Subsurface Connectivity

Abstract

Abstract This work analyzes the feasibility of implementing water injection processes through subsurface connectivity between different formations through communicating wells, allowing the water to flow from a source aquifer to a depleted formation. It presents a 3-dimensional semi-analytical model for estimating water influx in reservoirs with bottom-water drive and analyzing interference between reservoirs when subsurface connectivity is carried out to supply energy from an aquifer. It applies to both finite and infinite aquifers and reservoirs sharing an aquifer. The general solution is obtained by solving the diffusion equation employing Laplace and Fourier cosine transforms and is presented in Laplace space, requiring a numerical inversion method to convert the results to the real space. The functionality of the analytical solution is evaluated with reservoir numerical simulation and communicating well models. Results show that implementing this solution brings notable advantages because the ultimate oil recovery factor improves considerably. Additionally, it delays the water encroachment in reservoirs adjoined to the source aquifer and reduces water production.