Technical Research On Oilfield Sewage Disposal System Of Weizhou 12-8W/6-12 Oilfield

Oilfield sewage disposal and discharge is always the emphasis and difficulty in the process of offshore oil and gas field development due to too much fluid production and too little space on the production platform.There are two kinds of oilfield sewage discharge way.One way is to directly discharge qualified sewage into the sea.The second way is to inject qualified sewage that is further treated into specific oil well and strata in order to realize the reservoir waterflood or achieve the goal of increasing production without increasing pollution in oil and gas field.Two kinds of production sewage discharge methods have strict requirements on the water quality of sewage.System research and analysis of many factors which will affect the quality of production sewage treatment is of great significance for putting forward optimization measures of production sewage treatment system and improving the quality of sewage.According to the research on common sewage treatment system and equipments of offshore oil and gas fields in china,combined with the current situation of production sewage treatment of Weizhou oilfield group in the west of the South China Sea,this paper has carried out the comprehensive analysis and research on production sewage treatment system of Weizhou 12-8 w/6-12 oilfield in Weizhou oilfield group.As a result,many factors which influence the quality of production sewage,such as equipments,operation and treatment system,are found.In the meantime,the feasible process optimization and equipment improvement scheme were put forward.By implementing a series of measures,such as optimizing backwashing process of hydrocyclone,adjusting the backwashing process of fiber ball filter,adding gas floating function to production water buffer tank,taking sand removal measure,etc.oil concentration in oilfield sewage reduces from 18 mg/L to 10 mg/L average.At same time,some other benefits,for example,making the sewage treatment system more stable,reducing the backwashing frequency of hydrocyclone,reducing the frequency of replacing filter fiber ball,etc.are gained.The practice shows that measures of Weizhou 12-8 w/6-12 oilfield,provided through the study,can improve the quality of oilfield sewage treatment,reduce the workload of oilfield daily operation and maintenance,decrease the costs of oilfield production and improve the oilfield economic benefits.