Study On The Effect Of AES Surfactant Compound System On Emulsification And Viscosity Reduction Of Heavy Oil

Most domestic heavy oils in China have the characteristics of high viscosity,high wax content and high colloidal asphaltene.High viscosity and high colloidal asphaltene heavy oil can not be transported and oil wells cannot be collected without emulsification and viscosity reduction during the long-distance transportation of crude oil pipelines or oil well production.Heavy oil will cause blockage in the pipeline,making the pipeline unusable or difficult to restart,which will lead to a reduction in the pipeline's ability to transport heavy oil,which will cause significant waste of resources and economic losses.Therefore,it is of great significance to improve the safety and economy of heavy oil pipeline transportation by carrying out research on the influence of the sulfate surfactant compound system on the emulsification and viscosity reduction of ultra-heavy oil.In this paper,the emulsification and viscosity reduction process of heavy oil is studied,and the viscosity method of heavy oil in a block of Liaohe is obtained by the experimental method of measuring viscosity.Based on the theory that heavy oil can form a stable two-phase oil-water interface molecular film under the action of surfactant,in order to reduce the viscosity of heavy oil and improve the flow performance of heavy oil.The use of sulfate surfactants,non-ionic surfactants,inorganic bases,organic bases,linear alcohols and other experimental reagents to emulsify and reduce the viscosity of heavy oil,using viscometer to measure the experimental data.The results show that AES has good temperature resistance.Under alkali-free conditions,the viscosity reduction effect of heavy oil emulsification is the best when the AES dosage is 2.0%,and the viscosity reduction rate is 91.26%.The emulsified viscosity-reducing effect of thick oil after 0.2%Na₂CO₃and 1%AES is the best,the viscosity-reducing rate is 95.65%.Straight-chain alcohol has emulsifying and solvating effects on the heavy oil.The n-amyl alcohol with a dosage of 5%makes the thick oil have the best emulsifying performance.The petroleum carboxylate produced by the reaction of alkali agent and petroleum acid can reduce the oil-water interfacial tension and form a stable oil-water interface molecular film.The mass fraction is 0.2%of Na₂CO₃and ethanolamine?ETA?composite oil-in-water?O/W?type The emulsion has the strongest emulsifying ability.The AES molecules,linear alcohol molecules and petroleum carboxylates are diffusely adsorbed on the oil-water interface to form a dense monolayer of surfactant,reduce the oil-water interfacial tension and prevent the emulsion from inverting.The combination of AES with a mass fraction of 1.0%,Na₂CO₃with a mass fraction of 0.2%,ETA with a mass fraction of 0.2%,and n-pentanol in an amount of 5%makes the viscosity of the heavy oil the lowest and the best emulsifying effect for the heavy oil.When used alone,lipophilic or hydrophilic nonionic surfactants can reduce the viscosity of heavy oil,but the viscosity reduction effect is not good.In the same compounding system,alkylphenol polyoxyethylene ether?OP-10?,sorbitan polyoxyethylene ether?Tween-80?and fatty acid polyoxyethylene ester?SE-10?are all mass fractions of With 1.0%compound,the viscosity reduction rate of heavy oil reaches 97.25%,96.46%and 96.94%respectively;with a mass fraction of 1.4%lauric acid diethanolamide?LETA?compound,the viscosity reduction rate of heavy oil reaches98.65%;The O/W emulsion in the LETA ternary compounding system is the most stable and does not exhibit phase inversion.