Wetting Mechanism And Design Of Multi-Flooding Reducing Viscosity Agent For Hongqian Crude Oil Of Karamay In Xinjiang

In this paper, a kind of reducing viscosity agent was analyzed by thin layer chromatograph (TCD), titration and other analytical methods. All the components was confirmed. Furthermore, a new kind of reducing viscosity agent was also developed based on the old one. The contents of ingredients were optimized by discussing the effect of mass fraction of various compositions on the viscosity and the interfacial tensions (IFT) between crude oil and water. The two reducing viscosity agents were applied to HongQian crude oil of Karamay in Xinjiang in a comparative way. Besides, the mechanism of reducing viscosity was also given by inversigating the wetting effect on the crude oil and pectin, paraffin by dynamic interfacial tension and contact angle.In chapter one, the development on the technology of enhanced oil recovery and oil displacement methods were overviewed. The function of surfactants, polymer and alkaline was compared. It is elaborated the mechanism of reducing viscosity and factors on the recovery efficiency. In the end, analytical methods of surfactants were generalized.In chapter two, the composition and content of a reducing viscosity agent were analyzed by two-step titration, weight analysis, precipitation analysis, atom absorption spectrum, thin layer chromatography and ultrasonic extraction. It was found that ultrasonic extraction was a effective way to separate the organic and the inorganic. A good separation performance was observed when developer was composed of 85% enthanol and ethyl aectate in a ratio of 1:6.In chapter three, a kind of new reducing viscosity agent was developed. Inorganic salts, mixed alkali composed of sodium hydroxide and sodium carbonate, anion surfactants sodium dodecyl benzene sulfonate (LAS) and sodium fatty alcohol ether sulfate (AES) and polyacrylamide (PAM) were mixed up as multi-flooding compositions. The contents of ingredients were optimized by discussing the effect of mass fraction of various compositions on the viscosity and the interfacial tensions (IFT) between crude oil and water. The results indicated that IFT and viscosity were decreased remarkably when inorganic salts were added. It was also found that the viscosity of Hongqian crude oil of Karamay of Xinjiang was reduced from 23690 mPa?s to 89.07 mPa?s with a reducing rate up to 99.64%, while IFT was lowered to 0.07499 mN/m accordingly when the mass fraction of inorganic salts, alkali and surfactant were 51.87%, 40.17%, 6.99%, respectively, the mass concentration of polymer was 800 mg/L, making up 1% aqueous solution with a mass ratio of oil to water of 7:3 at 50℃. Furthermore, laboratory evaluation showed that a high reducing rate up to 92% can be reached when the multi-flooding aqueous solution was applied to NO.9 Hongqian crude oil of Karamay of Xinjiang. In addition, the cost of multi-flooding can be lowered significantly because of the addition of more than 50% inorganic salts.In chapter four, Asphaltum, pectin, paraffin were distilled by solvent extraction from Hongqian crude oil of Karamay of Xinjiang. The effect on dynamic interfacial tension of oil and water and contact angle of the emulsion formed by mixing the new reducing viscosity agent solution and crude oil, pectin, paraffin, respectively, was investigated. As a result, the mechanism of reducing viscosity of this new reducing viscosity was proposed.