Evaluation of ASP method applied in the lower U sandstone of the Oriente Basin

Abstract

The natural decline of oil production in Ecuador is emerging as a significant challenge to the country's financial sustainability. Following a peak in 2015, there has been a steady decline in production, which will become even more pronounced in the coming years due to the closure of Oil Block 43. Maximizing the recovery factor of currently producing assets is fundamental to ensuring Ecuador's role as a net oil exporter. Enhanced oil recovery could be one of the main tools for increasing this recovery factor. In the specific case of mature fields in Ecuador, combined chemical methods such as alkali-surfactant-polymer (ASP) flooding may have significant application potential. Thus, this paper analyzes ASP performance in the lower U reservoir of an oil field in Ecuador's Oriente Basin. Numerical simulation models were constructed at the core, field vertical sweep, and field areal sweep scales. The results obtained show that the incremental recovery factor ranges between 3% and 12% when analyzing the core scale. Furthermore, when analyzing the conceptual scenarios from 6 years of simulation, the incremental recovery factor ranges between 3% and 4% when evaluating the areal sweep efficiency and between 10% and 12% when evaluating the vertical sweep efficiency. Finally, it was observed that the oil-water interfacial tension was reduced by up to two orders of magnitude and the water viscosity increased by one order of magnitude with the application of the method.