DEEP PLACEMENT GEL BANK AS AN IOR PROCESS: MODELING, ECONOMIC ANALYSIS AND COMPARISON TO POLYMER FLOODING

Commercial reservoir simulation software was used to model a five spot water flood in a synthetic vertically‑heterogeneous reservoir with cross flow. At 85% water cut, the pattern was either continued on water flood, converted to a polymer flood, or treated with a deeply‑placed stationary gel "doughnut" then continued on water flood. Floods were continued to 95% water cut. Production performance and economics were analyzed for the three processes. The methodology developed in this project enables real‑case comparison of oil recovery and economics to aid selection of an IOR process as an alternative to continuing the water flood to its economic limit. For the three‑layer reservoir of this study, simulation results show that both IOR methods lead to higher ultimate recovery than water flooding alone, with polymer flooding yielding the larger increase. However, due to slow oil bank formation and production, polymer flooding exhibits a delayed increase in oil rate which adversely impacts its economics. Deep gel placement yielded the highest NPV. Sensitivity analyses on deep‑placement gel cases show that distance from the injection well and size of the "doughnut" plug have the greatest effects on treatment performance for a given reservoir. Impacts of these and other parameters on treatment design are presented. Direct performance comparisons of water flooding, polymer flooding, and deep‑placement gels are provided. Engineers can used this methodology as a screening tool for choosing deep reservoir diversion or polymer flooding as a preferred IOR method for a given vertically heterogeneous reservoir.