| The production process of fatty alcohol demulsifier is mature,with good demulsification and dehydration effect and broad spectrum.It is the largest type of demulsifier used in the production of oil fields in China at present.However,with the development of oil field into high water cut period,in order to improve the oil recovery rate,a large number of strong alkali,polymer and other substances are added to the oil wells in the process of tertiary oil recovery,which increases the difficulty of demulsification and dehydration of crude oil Alcohol type demulsifier can not meet the production demand.Therefore,in order to meet the development of petroleum industry and improve the separation efficiency of crude oil produced liquid,it is necessary to prepare new demulsifier.In this paper,based on the fatty alcohol demulsifier,acrylic acid is polymerized first,then polyacrylic acid and fatty alcohol demulsifier base are esterified to synthesize the acrylic polyether ester demulsifier for crude oil.The main contents are as follows:?1?After selecting different types of demulsifiers and selecting suitable base materials by indoor dehydration experiment?bottle test method?,the better reaction conditions were determined by the single factor experiment method of various reaction conditions in the process of polymerization and esterification,and then design expert was used The software simulated and optimized the demulsifier synthesis process,and the fitting value of process parameter model was basically consistent with that of single factor test.The suitable synthesis conditions of HDTM are:the polymerization temperature of acrylic acid is 80?,the polymerization time is 6h,the input amount of acrylic acid is 9.9%of alcohol base material,the input amount of BPO is 0.9%of acrylic acid,the esterification temperature is 153?,and the esterification time is 3.8h.?2?The results of the analysis of the demulsifier before and after modification showed that the unsaturated double bond in acrylic acid was polymerized,and the polyacrylic acid and alcohol base were esterified to form acrylic polyether esterification.The reaction was complete.Gel chromatography was used to analyze the demulsifier before and after modification,and the intermolecular connection between the fatty alcohol base and the molecule was improved.Through thermogravimetric analysis of the modified demulsifier,HDTM has good thermal stability and is suitable for oil field demulsification and dehydration.?3?The physicochemical indexes such as p H value,cloud point,HLB value and surface tension of demulsifier before and after modification were determined.Through comparison,it was found that the demulsifier HDTM was acid enhanced,the cloud point increased and the surface activity increased,so its water solubility and hydrophilicity were better.It was easier to adsorb at the oil-water interface,lower the strength of the interfacial film,was conducive to demulsification of crude oil,and the demulsifying performance of demulsifier was evaluated by bottle test.The technological conditions of demulsification and dehydration were studied from the aspects of dosage,demulsification temperature,demulsification time and p H value.The better technological conditions were obtained by orthogonal experiment.?4?The effects of three inorganic salts Na Cl,Ca Cl2 and Al Cl3 on the surface tension and cloud point of demulsifier solution were studied.It was found that with the increase of the concentration of inorganic salts,the surface tension and cloud point of demulsifier solution decreased;the effect of Na Cl solution on the dehydration rate was found.It was found that the inorganic salts in the solution can improve the demulsification and dehydration rate of demulsifier,but the final dehydration rate decreased;different concentration and molecular weight of the demulsifier were aggregated The effect of acrylamide solution on the rate of dehydration is studied.The experimental results show that with the increase of polymer concentration and molecular weight in the solution,the oil water interfacial film strength increases and the dehydration rate decreases,which is not conducive to demulsification of crude oil.The influence of solid particles in crude oil emulsions on dehydration rate is simulated by using bentonite.The results show that with the increase of solid particle concentration in crude emulsion,the dehydration rate decreases first and then increase.The experimental results show that with the increase of Na OH concentration,the dehydration rate first decreases and then increases. |
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