Research institute of Petroleum Industry (RIPI) Journal of Petroleum Research 2345-2900 34 1403-3 2024 08 22 Experimental Investigation of Dissolution and Precipitation by Injected Water Incompatibility in Low Salinity Water Injection in Oil Fields Experimental Investigation of Dissolution and Precipitation by Injected Water Incompatibility in Low Salinity Water Injection in Oil Fields 94 117 1433 10.22078/pr.2024.5314.3362 FA Saeed Abbasi EOR Study Center, Petroleum Engineering Research Division, Research Institute of Petroleum Industry (RIPI), Tehran, Iran Behjat Karipayhan EOR Study Center, Petroleum Engineering Research Division, Research Institute of Petroleum Industry (RIPI), Tehran, Iran Mohammad Heshmati EOR Study Center, Petroleum Engineering Research Division, Research Institute of Petroleum Industry (RIPI), Tehran, Iran Journal Article 2023 11 20 The water injection process, especially low salinity water injection (LSW), is one of the significant processes in enhanced oil recovery. Mainly, different mechanisms are based on the type of rock and fluid in the water injection process in the reservoir. In this research, seawater and diluted water are injected into calcite reservoir rock in reservoir condition. Dissolution and precipitation mechanism by water incompatibility have considered and investigated. The competition between dissolution and precipitation mechanisms, have evaluated by concentration change in outlet of injected core, and permeability change. The results have shown that the dissolution mechanism is dominant in low salinity and seawater injection. In addition, precipitation have observed as an effect on permeability reduction. The competition between mechanisms and contact time effect is investigated by water co-injection into core sample. The results have shown that scale deposition can cause low effect on permeability reduction because dissolution. Also concentration change did not show ion exchange for magnesium ion in precipitation. Thus, the contrast between the precipitation of water incompatibility and dissolution mechanisms in the permeability changes are a function of the rock structure and injection fluid composition, as well as the temperature conditions, as are shown in the results. The water injection process, especially low salinity water injection (LSW), is one of the significant processes in enhanced oil recovery. Mainly, different mechanisms are based on the type of rock and fluid in the water injection process in the reservoir. In this research, seawater and diluted water are injected into calcite reservoir rock in reservoir condition. Dissolution and precipitation mechanism by water incompatibility have considered and investigated. The competition between dissolution and precipitation mechanisms, have evaluated by concentration change in outlet of injected core, and permeability change. The results have shown that the dissolution mechanism is dominant in low salinity and seawater injection. In addition, precipitation have observed as an effect on permeability reduction. The competition between mechanisms and contact time effect is investigated by water co-injection into core sample. The results have shown that scale deposition can cause low effect on permeability reduction because dissolution. Also concentration change did not show ion exchange for magnesium ion in precipitation. Thus, the contrast between the precipitation of water incompatibility and dissolution mechanisms in the permeability changes are a function of the rock structure and injection fluid composition, as well as the temperature conditions, as are shown in the results. https://pr.ripi.ir/article_1433_b069b3415151fa7217e870017374de7c.pdf