Impact of Dopants on SCAL Experiments, Phase II

After the publication of Impact of Dopants on SCAL Experiments Phase I in 2024, this second part is thefollow up of the investigation of the effects of adding sodium iodide (NaI) to the formation brine and injectionbrine during laboratory waterflooding experiments. The first paper had pointed towards a non-trivial role ofNaI in wettability alteration on sandstone rock. This alteration could introduce a significant bias in the SCALexperiments. These phase II experiments are focused on the study of 6 carbonate samples (Richemontcarbonate rock). The samples were initially saturated with undoped or doped brines, brought to irreduciblewater saturation (Swi) and aged using crude oil at reservoir temperature. The samples were then loaded inAmott cells for spontaneous imbibition before being brought to residual oil saturation (Sor) during centrifugeforced imbibition. The results are showing some divergences with Phase one experiment. The spontaneousimbibition has not shown any correlation between NaI concentration and produced volume. Unlike phase onewith sandstone rocks, the main difference between undoped and doped brine effect appears during the forceddrainage showing a slight but systematic decrease in recovery factor for samples with NaI doped brine. Furtherwork is still required to assess the impact of iodide in oil phases, such as the impact of organic dopants likeiododecane.