Investigation of scale formation during injection of sea water into oil fields

sea water injection is used as a secondary enhanced oil recovery in oilfield but upon the incompatible mixing between the injection sea or brackish water and formation water in reservoir leads to the supersaturated brine that produces the mineral scale. temperature alteration in reservoir , production and injection tubes will also produce the supersaturated bring where consequently the mineral scale is formed. for prediction the type and amount of mineral scales the OLI software has been employed. due to incompatible mixing and temperature alteration inoil reservoir the various scales such as calcium sulfate, barium and strontium sulfates are formed. the siri oil field including siri-C,siri-D,siri-E and nosrat in persian gulf in south of iran is selected as a case study. using the OLI software, the sulfate and carbonate mineral scales are predicted through solid-liquid equilibrium calculations and the effects of temperature and injected sea water percent in reservoir are investigated.

Keywords:

scale formation , formation damage , water flooding , incompatible mixing precipitation.