Novel Coupling Smart Water-CO₂ Flooding for Sandstone Reservoirs; Smart Seawater-Alternating-CO₂ Flooding (SMSW-AGF)

Author

Hasan N. Al-Saedi
Ralph E. Flori, Missouri University of Science and TechnologyFollow

Abstract

CO₂ flooding is an environmentally friendly and cost-effective EOR technique that can be used to unlock residual oil from oil reservoirs. Smart water is any water that is engineered by manipulating the ionic composition, regardless of the resulting salinity of the water. One CO₂ flooding mechanism is wettability alteration, which meets with the main smart water flooding function. Injecting CO₂ alone raise an early breakthrough and gravity override problems, which have already been solved using water alternating gas (WAG) using regular water. WAG is an emerging enhanced oil recovery process designed to enhance sweep efficiency during gas flooding. In this study, we propose a new method to improve oil recovery via synergistically smart seawater with CO₂. This new method takes advantage of the relative strengths of both processes. We hypothesized that SW depleted in NaCl provided more oil recovery. We also added that depleting NaCl in seawater is not the end of the story; diluting divalent cations/anions in the seawater depleted in NaCl provides higher oil recovery. Injecting smart seawater depleted in NaCl with diluted Ca²⁺ and CO₂ resulted in a high oil recovery percentage among the other scenarios. Thus, the above water design was applied as a WAG in three cycles, which resulted in a much higher oil recovery of 24.5% of the OOIP. This improved heavy oil recovery is a surprising and promising percentage. The spontaneous imbibition agreed with the oil recovery results. This study sheds light on how manipulating ions in the water used in WAG can significantly enhance oil recovery.

Recommended Citation

H. N. Al-Saedi and R. E. Flori, "Novel Coupling Smart Water-CO₂ Flooding for Sandstone Reservoirs; Smart Seawater-Alternating-CO₂ Flooding (SMSW-AGF)," Proceedings of the SPWLA 60th Annual Logging Symposium (2019, The Woodlands, TX), Society of Petrophysicists and Well-Log Analysts, Jun 2019.

The definitive version is available at https://doi.org/10.30632/T60ALS-2019_DDD

Meeting Name

SPWLA 60th Annual Logging Symposium (2019: Jun. 15-19, The Woodlands, TX)

Department(s)

Geosciences and Geological and Petroleum Engineering

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2019 Society of Petrophysicists and Well-Log Analysts and The Authors, All rights reserved.

Publication Date

19 Jun 2019