Modelling, Simulation, and Performance Analysis of Waterflooding in Naturally Fractured Reservoir

The petroleum industry widely uses water flooding as a secondary recovery technique in petroleum reservoirs; however, in Naturally Fractured Reservoirs (NFRs), dual-porosity and dual-permeability features lead to rapid water breakthrough, poor sweep efficiency, and reduced oil recovery, thereby diminishing the effectiveness of water flooding. Despite the use of packages such as MRST (Matlab Reservoir Simulation Toolbox) and BOAST-NFR (Black Oil Applied Simulation Tool for Naturally Fractured Reservoirs) for analysing water flooding performance in NFR, accurate modelling of matrix–fracture interactions and prediction of breakthrough behaviour remain significant challenges. This study aims to construct a synthetic 3D geological NFR model using MATLAB-MRST and to evaluate water-flooding performance using BOAST-NFR, with a focus on reservoir pressure and cumulative production volumes. Although limited to synthetic data from a single injector–producer setup, the research is significant for advancing understanding of water flooding in complex fractured systems, offers a cost-effective means of testing scenarios, and contributes to improved strategies for NFR management. The water flooding simulation in an NFR using BOAST-NFR revealed typical reservoir-depletion and pressure-drop behaviours. The study concludes that BOAST-NFR is a valuable screening tool for assessing water flooding in dual-porosity reservoirs despite its limitations in modelling matrix-fracture interactions. The result shows cumulative oil production of 1.48 MMSTB (28% recovery factor) after 10 years. It is recommended to maintain output while oil rates are high, apply pressure maintenance and water management strategies, prioritise early production, monitor watercut closely, and evaluate enhanced recovery techniques to maximise ultimate recovery and reservoir longevity.