Research On Key Technical Parameters Of Oily Wastewater Treatment In Daqing Oilfield

At present, Daqing oilfield has entered the last stage of oilfield exploitation. With the development and application of the second and third oil production technology, water found in crude oil increases a lot and the components of produced liquid become more and more complex. What’s worse, after the processing of crude oil a lot of wastewater is produced. Currently, wastewater caused by the production of oil every year in Daqing oilfield has reached more than four billion and one hundred million cubic meters. Through the reinjection of, wastewater, less pollution is caused and the consumption of the surface water resource is reduced. Meanwhile economic and environmental benefits are brought in.The components of wastewater are very complex, it includes crude oil, inorganic ion, sulfide, bacteria, solid particles, demulsifier, flocculant,bactericide and other chemicals added in processing crude oil. So before the reinjection,it is necessary for us to take effective measures to treat oily wastewater by using sewage treatment technology. The purpose is to remove the oil, suspended solids and other impurities and recycle sewage oil.The main sewage treatment methods include biological method, physical method, chemical method, physical and chemical method and so on, single treatment method is often ineffective. In practice, the combination of a variety of methods which overcomes the limitation of a single way can make the quality of the effluent reach the standard. Gas bearing oil plus microbial reaction plus solid-liquid separation plus filtration has become the main procedure of Daqing oilfield wastewater treatment. Compared with other technological processes, it has great advantages in effective treatment, less costs of the investment and environmental protection. It is an ideal and practical wastewater treatment technology in Daqing oil field. Recently a new and mature technology of ceramic membrane ultrafiltration for water injection has been started to use in the low permeability and extra low permeability reservoir.This technology can reach the conventional treating standard,but the investment is large and the operating cost is high.This thesis compared and anylised the results of different wastewater treatment methods. Through the study of the quality of effluent water, the data analysis of economic cost,consideration of the key influencing factors, combination of the key technical parameters during the processing treatment and the optimization of operating the parameters, this thesis has put forward reasonable suggestions on improving the quality of wastewater treatment and reducing operating costs.