Abstract: In the process of offshore oil exploitation,oilfield production water is often re-injected after being treated to be qualified in order to supplement energy to the formation. This can improve the oil recovery rate,and also avoid marine environmental pollution caused by the discharge of production sewage into the sea. However,how to make the re-injected production water meet the requirements of oilfield re-injected water quality,to prevent the corrosion and scaling of the gathering and transportation system and wellbore,and to minimize the damage of the re-injected water to the formation,has been a difficult problem in oilfield production water treatment. According to the actual production situation of an offshore oilfield,this paper analyzes the water quality of the oilfield and puts forward corresponding optimization measures.

Key words: production water treatment, re-injection, water quality analysis