Description
An immiscible hydrocarbon foam (HC-Foam) enhanced oil recovery (EOR) pilot has been designed and implemented in a hydraulically fractured tight reservoir in the Woodbine field, Texas in partnership between MDAE and Dow. A single horizontal injector and two surrounding horizontal producers pad was developed for an IOR/EOR pilot. Water and produced hydrocarbon gases were injected individually, alternately as well as in co-injection mode, however no sustained incremental oil was observed. Injected gas and water broke through on the order of days. The injector showed more connectivity with one of the producers, suggesting a strong areal conformance problem. The objective of the pilot was to correct the conformance issues identified as out of zone injection loss and non-uniform areal sweep. A foaming formulation was developed that showed desired performance in lab. During this pilot, the developed surfactant formulation was injected at different concentrations and injection gas fractions for 5 weeks, out of which a strong foam was formed only for 2 weeks. The pilot met all of the success criteria: mobility and injectivity control, out of zone injection elimination, fluid diversion to bypassed areas, increased oil production rates, increased gas utilization ratio, better volumetric sweep, and sustained production after stopping of surfactant injection. The increased oil production sustained for at least for 6 weeks after the surfactant injection period. Current work confirms the technical efficacy and potential of the gaseous foam conformance solution for incremental oil production in unconventional plays.