EOR by water injection with nanoparticles into a carbonate oil reservoir

Abstract

One of the type of well-known smart waterflooding is injection of different nanoparticles mixed with low-salinity or formation water. Previous studies showed a good potential of the nanoparticles as EOR method. But the biggest restriction of full-field applying is the cost of the nanoparticles. We found out that products of different factories, electric power plants etc. could be used as the nanoparticles for EOR technologies and expenses for its preparation are much lower. This paper presents the results of laboratory studies and 3D simulation of water injection with Ca, Si and Al-based nanoparticles into a carbonate oil reservoir. Laboratory studies included preparation of cores, scanning of cores and double core flooding using formation water and the same water with nanoparticles. Then the injection was simulated at 3D pilots of the carbonate reservoir of the Romashkinskoe field. Laboratory tests and 3D simulation showed that the incremental oil recovery with injection of the nanoparticles is around 15–27% (displacement coefficient) and 2–5% (recovery factor) respectively. The nanoparticles are much smaller than pore throats. Thus, we assume that the effect could be explained by reduction of interfacial tension and some wettability alteration.