Spontaneous Imbibition Test of Low Salinity Injection at Low Saline Waxy Crude Carbonate

Abstract

Low salinity waterflooding (LSW) is categorized as one of emerging EOR technologies. It is done by injecting water with different salt composition and/or concentration. The research has been carried out for both sandstone and carbonate with the results looks promising. However, most of this research still concentrated in the north sea, middle east and North America region. This article discusses the applicability of low salinity waterflooding methodology in Indonesia. Spontaneous imbibition test is carried out to observe the recovery gain from a various combination of concentration and composition of the injected brine. The change of pH of the brine is also examined in order to confirm the pH effect mechanism. Three different concentration of brine (500 ppm, 5.000 ppm, and 10.000 ppm), three different brine composition (NaCl, CaCl2, and MgCl2) and high paraffinic crude oil are used as the fluid sample. It is found that the increased oil recovery is significant at a salinity of 10,000 ppm for MgCl2 and 5,000 ppm for NaCl ions. While the lowest recovery was shown by the test at a salinity of 500 ppm

Enhanced Oil Recovery in Terrigenous Oil Fields Using Low-Salt Water

“…As well as salinity, the ionic composition of the injected water may play a significant role in increasing oil recovery. CaCl 2 and NaCl solutions were prepared, for example, when studying low-salt waterflooding on core (Lie Yang et al 2016;Al-Obaidi 2021;Hidayat, Erfando & Maulana 2018). Having the same salinity of 5000 mg/l, the sodium solution increased the oil recovery factor by 7% more than the calcium solution.…”

Effect of Salinity on the Imbibition Recovery Process of Tight Sandstone Reservoirs

“…Song explained that the change in 2 of 12 wettability was caused by less Na+ surface complexes in low-salinity water by calculating the electrostatic component of the separation pressure [10]. Experiments by Hidayat found that brine solutions containing high Mg 2+ and Ca 2+ significantly improved the recovery efficiency of osmotic water [11]. The explanation for this phenomenon by Ghandi et al is that the brine solution containing divalent ions such as Mg 2+ and Ca 2+ can change the wettability of lipophilic rocks to low lipophilic or neutral wettability, thereby improving the imbibition recovery [12].…”