This paper investigates the application of a proprietary surfactant-solvent package as an alternate chemical solution in Enhance Oil Recovery (EOR). This micro-emulsion system (MES) has many upsides to traditional solvent or surfactant-alone alternatives, as the package can be transported in-depth with less sacrificial adsorption yet maintain its interfacial tension reduction and oil swelling abilities to mobilize residual oil.

While designing conformance jobs over the past several years, it has been observed that often times the injected fluids tend to travel through high permeability channels between a binary pair(s) of injector and producer. This short-circuit of injected fluids leaves residual oil in the channels and renders a large volume of the reservoir unswept. This paper examines the specific MES application where a high permeability channel is treated to mobilize the residual oil. The characteristic of the high permeability channel is based on production data and is comparatively relative to the total flood zone between a producer and an injector. Due to the small size of the channel the mobilized oil will be produced quickly resulting in attractive economics (due to smaller volume of treatment required). Due to quick response and attractive economics, there will be added incentive and field data to decide whether to expand the treatment on a field wide basis. Subsequently, the moving forward plan could be that once the treatment is validated, this process will be used in conjunction with conformance control along with Polymer as mobility control drive fluid for fieldwide expansion.

Laboratory core flood experiment shows that a 1.0 PV slug of 1 gallons for thousand gallons (gpt) of the complex MES additives recovers about 9-12% OOIP (23-27% OIP). The experiment shows that an increase of oil cut from 1% to 12% occurs due to use of the complex MES. The laboratory experiment was performed with oil saturated Torrey Buff sandstone core. The results of this experiment were simulated using CMG's STARS simulation tool. The laboratory results were scaled up to test in two pilot configurations where the remaining oil in the channels was the primary target of the simulation exercise.

The first pilot is a quarter 9-spot with one injector and three producers. The second pilot is a central injector in the up-dip of the structure with 5 producers. The simulation results show that the peak oil production due to the effect of the MES is very significant. The economic analysis indicates attractive returns over continued waterflood for both pilots.

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