Modification of Gulf Seawater for Possible Use in Improving Oil Recovery of Carbonate Formation: Mechanism Investigation

  • Abdulrazag Zekri, Mohammad Jasem Khalifi, Hazim Al-Attar, Mamdouh Ghannam

Abstract

Water flooding is by far the most common technique for improving oil recovery used by the oil industry. Displacement efficiency of water flooding is affected by crude oil/water/rock interactions. Historically, some consideration was given to such interactions in the practice of reservoir engineering. In recent years, extensive research work in this area has showed that higher oil recoveries can be obtained through dilution and/or modification of the ionic composition of injection water.  While laboratory tests and historical field evidence validated this observation in carbonate reservoirs, the mechanism behind the observed incremental increase of oil recovery is still a topic of discussion. In this work, Gulf seawater was selected as a base water and its concentration & composition were modified through dilution and/or spiking with sulfate.

The base water was diluted with water 10 and 50 times and spiked with sulfate to 2 and 4 times its initial sulfate concentration. Interfacial tension, contact angle, imbibition, and core flooding experiments were performed to determine the optimum flooding system and highlight the process mechanism. End-point water relative permeability, chemical analysis of the effluents, water resistivity, turbidity, and pH were measured prior and post-flooding experiments. Results showed that the dilution of Gulf seawater can significantly improve the displacement efficiency for the selected oil reservoir, and we observed no significant improvement in the displacement efficiency through spiking with Gulf seawater with sulfate. Results also attributed the improvement of oil recovery to two mechanisms, mainly water-in-oil emulsion and rock dissolution.

Published
2020-03-30
How to Cite
Abdulrazag Zekri, Mohammad Jasem Khalifi, Hazim Al-Attar, Mamdouh Ghannam. (2020). Modification of Gulf Seawater for Possible Use in Improving Oil Recovery of Carbonate Formation: Mechanism Investigation. International Journal of Advanced Science and Technology, 29(3), 12960 - 12976. Retrieved from http://sersc.org/journals/index.php/IJAST/article/view/30450
Section
Articles