A reactive transport approach for modeling scale formation and deposition in water injection wells

Abstract

Petroleum industry is moving toward enhancing oil recovery methods, especially water-based methods, including low salinity and smart water flooding which water with an optimized composition is injected into the reservoir for improving oil recovery. Injection of water into the target formation is also a common operation in geothermal energy production. As the water is being injected into the reservoir, pressure and temperature change along the well column and cause scale formation. Mineral scale precipitation and deposition is a common problem for water injection wells which reduces the effective radius of the wellbore and affects the injection efficiency.In this paper, modeling scale precipitation and deposition in a pipe flow system by coupling of species transport model and a geochemical software package (PHREEQC) is investigated. The results of the proposed method were matched with experimental data. The model has been used for prediction of scale precipitation and deposition profile along with water injection wells during low salinity waterflooding. The results show deposition of calcium carbonate scale in the bottom section of the water injection wells. Higher temperature, higher salinity and more rate fluctuation cause an increase in scale precipitation and deposition in the wellbore condition.