Studies On Demulsification For Polymer/Surfactant Flooding Produced Liquid

This paper briefly introduces the development and current research status of surfactantpolyacrylamide(SP) multisystem flooding and the study of crude oil emulsion demulsificationtechnology progress. In this paper, we analyzed the properties of Daqing crude oil, andseparation of active component of crude oil (colloid asphalt). During the preparation process,the effect of active components in crude oil and the content of oil displacement agent on thestability of the emulsions were studied, by centrifugal sedimentation dehydration rate, theviscosity of the emulsion, the particle size of oil-water emulsion and the wetting angles; thisarticle analyzed the result of different structural demulsifiers to different crude oil emulsions.The results showed that colloid and asphaltene can increase the viscosity of the emulsion,and the density of emulsion,thereby enhancing the stability of the emulsion, emulsiondemulsification dehydration harder. By dehydration rate measurement standard, the effect ofthe content of colloid and asphaltene on the stability of emulsions were investigated, withdemulsification temperature70℃, demulsifier added amount150mg/L, demulsification4h;the asphalt content of threshold value was0.5%, the colloid content of threshold value was20%; Under the simulated field demulsification conditions, for high asphaltene contentemulsion, the demulsification dehydration rate of different structural demulsifiers in the orderwas: BP169>AR23>AE8051>AP199>SP169≈PFA8311≈TA1031; while for high colloidcontent emulsion the order was:AE8051>BP169>AP199>AR23>SP169≈PFA8311≈TA1031;the demulsifier of wetting angle rate larger have good effect on the demulsification ofemulsion including the colloid and asphaltene.Four kinds of demulsifier{more ethylene polyamine polyether oil solubledemulsifier(AE8051、AP199)、phenolic resin polyether water-soluble demulsifier (AR23)、three block alcohol polyether oil soluble demulsifier(BP169)}for emulsion containing highcolloid and asphaltene demulsification effect is better; So the molecular structure containsmore branched chain, block number demulsifier is suitable for the high colloid and asphaltenecrude oil demulsification.With the increase of polyacrylamide and petroleum sulfonates content, the viscosity ofemulsion increase, emulsion demulsification dehydration is harder, the diameters of emulsionparticles is evenly distributed, thereby enhancing the stability of the emulsion; For containingpolymer emulsion, the demulsification dehydration rate of different structural demulsifiers inthe order was:AR23>BP16>AP199>SP169>PFA8311≈TA1031≈AE8051≈空白；Along withthe increase of the petroleum sulfonate concentration, the demulsification effect of thedemulsifiers was poorer. For containing petroleum sulfonate emulsion, the demulsificationdehydration rate of different structural demulsifiers in the order was: BP169>AR23>AP199>AE8051>SP169>PFA8311>TA1031.Containing the polymer, surfactant emulsion breaking process, as the initiator withpropylene glycol triblock demulsifier BP169, as the initiator in benzene formaldehyde etherdemulsifier AR23diblock good demulsification, after breaking the emulsion dehydration rateof up to70%or more; while the eighteen alcohol as the initiator triblock ether demulsifierSP169, with phenol amine resin as the initiator of the two block ether demulsifier PFA8311and TA1031results with and without dehydration rate emulsion demulsifier similar, breakingeffects are poor. The influence of the structure of demulsifiers to the abilities of dewateringseems has little relationship with the rules that the impact of the structure of demulsifiers tothe oil phase-wetting angle. Demulsifier for crude oil wettability can not fully express itsdemulsification performance while the polymer or surfactant is existing in the emulsion...