胺型乳状液的二氧化碳、氧化钙响应行为及应用潜力

CO_(2)/CaO-responsive behavior and application potential of amine emulsion

采用绿色、低廉的CO_(2)/CaO刺激诱导胺型乳状液,在揭示该乳液体系响应行为规律的基础上,构建CO_(2)/CaO响应性油基钻井液并评价其性能。研究表明,在CO_(2)诱导下胺型乳状液易从油包水逆转为水包油,同时其黏度经历了降低、回升、降低的规律性迁移,上述CO_(2)响应行为可由CaO诱导回转。基于胺型乳状液构建的油基钻井液,在油水比50∶50至70∶30,密度1.4~2.0 g/cm^(3)及温度160℃条件下均具有良好的流变和滤失性能,且可被CO_(2)鼓泡清洗,可由CO_(2)诱导大幅降黏并有效清除低密度无用固相,所余液相可由CaO诱导回用。机理分析表明,CO_(2)/CaO诱导胺型乳化剂与其胺盐之间可逆转换,使乳化剂亲油亲水平衡性可逆调节、乳状液粒径可逆增减,是胺型乳状液类型、流变性可控可逆的根本原因。图14表2参33。

Green and low cost CO_(2) and CaO were used to stimulate amine emulsions to reveal the responsive behavior of amine emulsions. On this basis, oil-based drilling fluids responsive to CO_(2) and CaO were formulated and their properties were evaluated. The results showed that the amine emulsions inversed from water-in-oil state to oil-in-water state readily and their rheological behavior underwent transitions of decreasing, rising again and decreasing again via induction by CO_(2). These CO_(2) responsive behaviors could be reversed by CaO. Oil-based drilling fluids prepared based on the amine emulsions with oil-water volume ratios of 50:50 to 70:30, densities of 1.4–2.0 g/cm^(3) had good rheological and filtration properties at 160 ℃;and be readily cleaned up using CO_(2) bubbling. The useless solid phase with low density could be removed efficiently via reducing the viscosity of emulsion by CO_(2) and the residual liquid phase could be restored to the original state by CaO and reused to prepare drilling fluid. The mechanisms analysis indicated that CO_(2)/CaO induced the reversible conversion between amine emulsifiers and their salts, which enabled the reversible regulation of both the hydrophilic-lipophilic balance of amine emulsifiers and the emulsion particles’ size and finally caused the controllable-reversion of the form and rheology of amine emulsion.