Abstract

The energy sector as well as daily needs of our day to day life depends majorly on the utilization of crude oil and its derived products. Therefore, to overcome the basic demands it is mandatory to extract crude oil from existing matured reservoirs. In this work, we have investigated the mechanistic studies of emulsification as well as nano-emulsification and identifying their role on heavy residual oil recovery. The heavy was oil emulsified using surfactants and polymer which were stable up to 24 hours and this assists in improving the trapped residual oil displacement efficiency, thereby reducing the saturation of residual oil inside the reservoir. On the other hand, when nanoparticles were introduced in the same surfactant-polymer system, nano emulsions were observed whose stability were enhanced at a greater rate (up to days) and thus further assist in improved the residual oil recovery. It was observed that average size of the nano-emulsion in microns were smaller (with more number of droplets) as compared to emulsion. This phenomena thereby enhances the stability period and diverts the displacing fluid to cover more area of the reservoirs resulting in higher oil recovery due to higher sweep efficiency. Moreover, core flooding experiments conducted showed an oil recovery of 18% (residual oil in place, RIOP) and was enhanced to 26% RIOP when nanoparticles was deployed in the system.The energy sector as well as daily needs of our day to day life depends majorly on the utilization of crude oil and its derived products. Therefore, to overcome the basic demands it is mandatory to extract crude oil from existing matured reservoirs. In this work, we have investigated the mechanistic studies of emulsification as well as nano-emulsification and identifying their role on heavy residual oil recovery. The heavy was oil emulsified using surfactants and polymer which were stable up to 24 hours and this assists in improving the trapped residual oil displacement efficiency, thereby reducing the saturation of residual oil inside the reservoir. On the other hand, when nanoparticles were introduced in the same surfactant-polymer system, nano emulsions were observed whose stability were enhanced at a greater rate (up to days) and thus further assist in improved the residual oil recovery. It was observed that average size of the nano-emulsion in microns were smaller (with more number of droplets) as compared to emulsion. This phenomena thereby enhances the stability period and diverts the displacing fluid to cover more area of the reservoirs resulting in higher oil recovery due to higher sweep efficiency. Moreover, core flooding experiments conducted showed an oil recovery of 18% (residual oil in place, RIOP) and was enhanced to 26% RIOP when nanoparticles was deployed in the system.