Predicting scale formation in wastewater disposal well of Rag-e-Safid desalting unit No. 1

摘要

Rag-e-Safid desalting unit No. 1 produces 3,126 barrels per day (bbl/d) of wastewater from oil processing in Rag-e-Safid oil field. This much wastewater, due to the high amount of minerals and total dissolved solids (TDS) is injected to disposal well - A through a 6-inch, 20-km pipeline. Injection of this wastewater into disposal well has had great damage and incurred high costs to Iranian oil company due to inorganic scales and corrosion damage in wastewater injection pipelines, wellhead and down-well equipment, the need for work over the well, and acidizing operations to remove scales. This article presents the predicting scale tendency and scale precipitation at different pressures, temperature, and mixing ratios of injection wastewater with formation water in disposal well - A of Iranian oil field. The experimentally measured chemical analyses of formation water and injection water were used by Scale Soft Pitzer software to determine the formation of these scales. This software has been applied to investigate the potential of scale formation in disposal wells of oil fields.