Evaluation of Enhanced Oil Recovery Potential Through Water Flooding in Abandonment-Stage Reservoirs of OML 14, Edo State, South South Nigeria

Water flooding is the most widely employed improved oil recovery technique globally, and its application to abandonment-stage reservoirs in the Niger Delta offers significant potential for extending field life and recovering remaining oil in place. This study evaluates the water flooding potential of three mature reservoirs approaching economic abandonment in OML 14, Edo State. Static and dynamic reservoir models were constructed using available well log, core, and production history data to characterise remaining oil saturation distributions. Material balance calculations using the Havlena-Odeh method were applied to quantify total original oil in place and cumulative recovery to date. Reservoir heterogeneity analysis using the Dykstra-Parsons coefficient revealed strong vertical permeability contrasts that historically limited sweep efficiency under primary depletion. Reservoir simulation using Eclipse 100 was employed to forecast incremental oil recovery under three water flooding pattern options: line drive, five-spot, and staggered line drive. The staggered line drive pattern yielded the highest incremental recovery factor of 14.7 percent of remaining oil in place, taking into account vertical heterogeneity and areal sweep efficiency losses. A preliminary economic evaluation at current Bonny Light crude prices confirms technical viability at injection water disposal costs below 2 USD per barrel. Recommendations are made for pilot flood design and injectivity testing. Keywords: water flooding, enhanced oil recovery, Edo State, reservoir simulation, abandonment-stage reservoirs.