Development And Performance Evaluation Of Chemical Paraffin Remover&Inhibitor Of Oil Wells

At present,most oil fields contain high content of paraffin in China.Wax deposition can seriously affect the normal production of oil wells,which will even cause the oil well to stop production.In addition,wax deposits will clog the pipeline and reduce the transportation efficiency of the pipeline.The residual paraffin deposit in the end-of-life pipeline will permeate the earth and pollute the environment.Wax removal measures should be taken to remove the paraffin deposits before the pipeline is abandoned to protect the environment.Therefore,it is of great significance to develop efficient wax removal agent for the normal production of oil well and the environmental disposal of end-of-life pipelines.At the same time,it is also of practical significance to develop efficient paraffin inhibitor to prevent paraffin deposition in oil wells and pipelines.In accordance with the requirement of environmental protection for the disposal of end-of-life oil pipelines put forward by China Petroleum Pipeline Bureau,a high efficient water-soluble wax remover was prepared in this paper.According to China's oil and gas industry standards SY/T6300-2009 Technical requirements for wax cleaning and prevention for oil production,first,the solvent with better wax dissolution effect is screened out,and then the best combination is selected by using the solvent with better wax dissolution effect.Finally,the solvent can be fully mixed with water by adding a certain amount of surfactants to facilitate the subsequent sewage treatment.The experiment concluded that: Four single solvents—carbon,benzene,hexane,petroleum ether—have better dissolving wax performance,the best combination is the mixture of carbon disulfide and petroleum ether with a volume ratio of 2:1.Surfactant Tween 80 and OP are the best,with the best dosage of surfactant being 15% of the total mass.Furthermore,styrene,maleic anhydride,allyl thiourea and octadecanol were introducted as raw materials to synthesize SM-ATUE high molecular wax inhibitor by copolymerization and esterification,and the properties of high molecular wax inhibitorwere determined by reverse cup method.Firstly,styrene,maleic anhydride and allyl thiourea were used as monomers,toluene as solvent,benzoyl peroxide as initiator to polymerize SM-ATUE,then SM-ATUE was synthesized by esterification of SM-ATU with octadecanol.Through the combination of single factor method and orthogonal experiment method,the optimum conditions for synthesis of SM-ATU were obtained by using the wax inhibiting rate as the reference standard.The experimental results show that: When the molar ratio of styrene,maleic anhydride and allyl thiourea is 3: 1: 2,the reaction temperature is 100 ?,the reaction time is 7 h,the amount of initiator is 1.5%,the synthesized polymer has a high wax inhibiting property,and the wax inhibiting rate is over 90%.