Generation and filtration of O/W emulsions under near-wellbore flow conditions during produced water re-injection

摘要

Produced water in the oilfield contains oil droplets in the form of oil-in-water (O/W) emulsions. These oil droplets cannot be completely separated from the water by surface facilities, and produced water still containing suspended emulsions is re-injected into formations. These oil droplets plug the pore space in the near-wellbore or near-fracture region, resulting in rapid declines in the performance of water injection wells where the remediation processes can be expensive. Displaced oil droplets also contribute to the plugging of pore space near injection wells. These oil droplets are generated by high-velocity flow displacing residual oil in the rock. Because generation and filtration processes occur simultaneously, it is critical to understand both processes at high-velocity flow conditions.