Experimental study on enhanced oil recovery (EOR) mechanisms of nanogel combining with low salinity water for carbonate reservoirs

"Nanomaterials have been widely studied and applied in the oil and gas industry. Among the developed nanomaterials, nano-sized crosslinked polymeric gel particle (nanogel) has shown great potential in recovering residual oil and improving oil recovery. This dissertation carried out their potential EOR mechanisms and the synergetic effect between nanogel and low salinity water. Nanogel used in this study was synthesized through the suspension polymerization process in our lab. The morphology, size distribution, and zeta potential were studied for nanogel dispersed in brine with variable ionic strength. The injectivity of nanogel was elucidated at first to ensure their in-depth penetration ability. The oil-water interfacial tension reduction and oil-in-water emulsion stabilization were studied with three kinds of nanogel and two types of oil at various nanogel concentrations, temperatures, and brine salinities. The core flooding experiments have indicated the residual oil can be fragmented and produced out in oil-in-water emulsion. This shear-induced emulsification property denotes nanogel can significantly improve oil phase mobility, especially for heavy oil. In addition, the diameter of emulsified oil drops in the effluent is inversely proportional to the shear rate. The synergistic effect between nanogel and low salinity water was found on both wettability alteration and interfacial tension reduction. From kinetic adsorption measurements, the adsorption was driven by both van der Waals force and electrostatic attraction during nanogel transport through porous media. The limestone flooded with nanogel and low salinity water achieved a 62.4% ultimate oil recovery. These results suggest that the synergistic effect between low salinity water and nanogel offers a promising platform for enhancing oil recovery"--Abstract, page iv.

Name thesis:degree_name

Ph. D. in Petroleum Engineering

Grantor

Missouri University of Science and Technology

Author dc:creator

• Han, Pu

• EOR
• Low salinity water
• Nanogel
• Petroleum Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2831

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3836