Preparation, Laboratory Evaluation And Application Of Environmental Protection Type Crude Oil Demulsifier And Paraffin Removers/inhibitors

The water content from extraction oil liquid of oil well rises rapidly with widely taking oil field water flooding, steam flooding measure in order to raising the liquid yield of the oil production. Meanwhile, technologies for tertiary oil extraction have been relatively well developed in recent years, with different oil recovery auxiliary chemicals are applied in oilfield to make extraction liquid composition of crude oil become complicated further more. It has became a key technology impacting to efficient and rapid the cost of oil extraction, the quality and quantity of oil and the control of environmental pollution. Hereby, studying, developing, producing and using new-type high-efficient demulsifier is really meaningful for crude oil.Acrylic acid monomer and styrene used as raw material, a new type of W/O crude demulsifier without alkoxy had synthesized by soap-free emulsion polymerization method. This kind of demulsifier doesn't use inflammable and explosive gases, and the raw material is cheap and easy to get. It has a good application and development Prospect.The optimum proportion of materials was acquired through the method of single factor and orthogonal test. The optimum proportion of crylic acid(AA), methacrylic acid(MAA), butyl acrylate(BA), methyl methacrylate(MMA), styrene(St) is 1.2:0.8:9.0:10.0:4.0. Effects of amount of water and initiator, reaction time, synthesis temperature etc on the properties of this polymer were studied. Thus, the best reaction condition is dosage of water of 80%, reaction time of 3.0h, polymerization temperature of 75℃, pH regulator of 0.4% and initiator concentration of 0.5%.To gain the actual performance of the new demulsifier, experiments of comparison dehydration between the synthesised demulsifier and commercial demulsifier have been done. Accurate testings on the dehydrated water volume and color have also been made. The results showed that the new demulsifier has good performance. By synergistic effect, we improved the performance of this demulsifier finally.The fracturing fluid was made of this compound demulsifier and other oilfield auxiliary chemicals. By performance test, we adjusted applying quantity of different oilfield auxiliary chemicals and improved the performance of the fracturing fluid. We compared this fracturing fluid with another fracturing fluid which was made of commercial demulsifier. The results indicated that the compound demulsifier has a good compatibility with other oilfield auxiliary chemicals.It can be used in field construction and has little formation damage.In the process of crude oil Exploitation, with the decreases of temperature and pressure, the paraffin can separate from the crude oil and deposite on the sidewall and casing pipe, which do harm to the oil-bearing reservoir and restrict oilfield normal production. Therefore, paraffin removal and control in oil wells is an indispensable part of oil production technology. By selecting solvents of paraffin removal, surfactants and assistants, a water-based emulsifier for paraffin removal/inhibition which with strong paraffin removal and stabilizing ability has been preparated. The density of the emulsion is 0.95g/cm³, the removal rate of paraffin is 0.4328g·L^-1·min^-1, and the saturating capacity of paraffin is 2.9244g. To the freezing phenomenon of the emulsifier for paraffin removal/inhibition in winter, we deal with it in antifreeze, and enhance the capability of the emulsifier. The paraffin remover and inhibitor has remarkable energy-saving effect when it is used in oil fields.