Study On Modification And Properties Of Polyether Crude Oil Demulsifiers

As an important energy and basic chemical raw material,petroleum is an important strategic resource in China.With the rapid development of social economy,the demand for petrochemical products is growing rapidly.The total amount of oil and natural gas resources in Xinjiang province is as high as 30 billion to 50 billion tons,accounting for more than a quarter of the national total,and is the province with the largest oil reserves in China.With the continuous development of tertiary oil recovery technology,Crude oil emulsions become more and more stable,and the water content is getting higher and higher,which not only increases the difficulty of oil-water separation,but also increases the burden on pumps,pipelines and storage tanks during transportation and refining,and the cost of crude oil extraction.At present,polyether demulsifiers,which are relatively mature and widely used in China,have been difficult to meet the needs of daily production of oil fields.In order to reduce the mining cost,the polyether demulsifier must be modified to improve its demulsification ability and efficiency,which is great significance to the development of the oilfield industry in Xinjiang province.In this paper,Based on the original polyether demulsifier,two modified synthesis processes are designed for the different crude oil emulsion of Karamay oilfield,and the demulsification dehydration experiment and structural characterization are carried out.The main contents are as follows:Based on the polyamine block polyether,the esterification reaction with acrylic acid is first carried out,and then an initiator is added to initiate polymerization of the double bond in the polyether acrylate to obtain the demulsifier with a more branched number and a larger molecular weight.After screening the monomer ratio,pretreatment,esterification reaction,polymerization reaction,stirring method,etc.,the acrylic modified OF series demulsifier are synthesized and its surface tension,infrared spectrum and molecular weight are characterized.At 45 °C,half the dose,the modified OF115 crude oil demulsifier has a higher demulsification effect on the oil emulsion of the Karamay oilfield than the existing demulsifier.Based on the polyamine block polyether,the esterification reaction with acrylic acid is first carried out,and then the hydrogen-containing silicone oil is added to cause a hydrosilylation reaction of the active hydrogen on the unsaturated double bond silicone oil skeleton in the polyether acrylate.A modified demulsifier having a larger number of branches and a larger molecular weight and having a silicone oil as a skeleton is obtained.A series of factors such as esterification reaction,hydrosilylation reaction,catalyst dosage,monomer ratio,type of polyether base,solvent dosage and synthesis process are screened to determine the optimal reaction conditions.The surface tension,infrared spectrum and molecular weight are characterized.At 75 oC,the modified of OF 125 crude oil demulsifier has better demulsification effect than the current demulsifier under the condition that the effective dosing amount is reduced by 40%.