Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

A study on North Sea chalk reservoirs reveals that managing the composition of injected water can significantly enhance oil recovery. Unlike previous research primarily using outcrop chalk samples, this investigation utilized reservoir chalk samples and employed waterflooding techniques with various brines, including distilled water, sulfate-containing brine, and magnesium-ion brine. The findings indicate that while potential determining ions like SO4 2–, Ca 2+, and Mg 2+ play a role in improving oil recovery, their interaction with the rock is not solely temperature-dependent. Additionally, the composition of formation water also influences oil recovery at high temperatures, suggesting a more complex interplay between injected brine and reservoir conditions. This research provides new insights into optimizing waterflooding processes for enhanced oil recovery in chalk reservoirs.

Zahid, A., Shapiro, A., Stenby, E. H., & Yan, W. (2012). Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs. Energy & Fuels, 26(6), 3407–3415. https://doi.org/10.1021/ef2008979