Study On The Treatment Of Liquid From A Combined Station In A Low Permeability Reservoir In Daqing Oilfield

In recent years,the development of low permeability reservoirs by acidizing fracturing technology in Daqing Oilfield has also complicated the crude oil components transported to the combined station.The natural emulsifiers,such as fracturing fluid,mud sand impurities and high content of glial asphaltene,have made the oil-water transition layer thicken,emulsifying condition is serious,and the crude oil is mixed with strong conductivity impurities.In this paper,crude oil in low permeability reservoir treated by a combined station in Daqing Oilfield was studied.The composition and characteristics of external liquid and five-in-one transition layer were analyzed.The organic solvent and inorganic impurity acid were used to analyze the organic and inorganic impurities in the transition layer.Fe²⁺and HS^-,in the external liquid and transition layer of the station to determine the presence of ferrous sulfide particles.To determine the factors affecting the treatment of production fluid in low permeability reservoir,to screen and compound demulsifier indoors,to select ferrous sulfide remover,and to carry out mine test to determine the best dosing scheme.The results show that the average particle size of crude oil is between 8.64μm and10.85μm in the transition layer of five-in-one electric dehydrator,the content of glial asphaltene in the transition layer is 11.8%,which is higher than that of the external liquid pipeline.The optimum treatment parameters of crude oil were obtained by field test.