油基钻井液用高性能乳化剂的研制与评价

Development and Evaluation of a High Performance Oil Base Mud Emulsifier

与传统的单链表面活性剂相比,低聚型表面活性剂作乳化剂具有更多优点.通过一种简单的方法,用有机酸、二乙烯三胺以及二氯亚砜等合成了一种三聚型酰胺类非离子表面活性剂.该乳化剂具有3个头基——酰胺基和3条烷基链,使其具备很强的分子内和分子间作用力,其分子在油水界面聚集吸附时,同时存在烷基链之间的分子内相互作用和依靠氢键而形成的分子间相互作用,极大地提高了其构建和稳定油包水乳状液的能力 研究表明：油水比为85：15时,加入2.0％AM-1,并以0.4％十二烷基苯磺酸钠作辅乳化剂配制的乳状液在50～220 ℃的温度范围内具有破乳电压值高（＞1 000 V）、乳化率高（＞91.0％）、析液量低（＜0.7 mL）的特点,而且乳状液液滴尺寸分布均匀,没有发生明显的聚集.以这种高性能乳化剂、改性腐植酸类降滤失剂SLJ-1和自制有机土为主处理剂,形成了一种抗高温油基钻井液体系,其密度在1.2～2.0 g/cm^3之间可调,抗温达220℃,流变性能好,能抗40％水或15％劣质土的污染.

A trimeric surfactant used as the primary emulsifier in oil base drilling fluid was synthesized with an organic acid, diethylenetriamine and thionyl chloride. The combination of this primary emulsifier and a secondary emulsifier, sodium dodecyl benzene sulfonate, gave birth to a high performance emulsifier formulation, RHJ-1, which has three head groups, i.e., amino group and three alkyl group chains, rendering RHJ-1 strong intermolecular and intramolecular forces suitable for generating strong and tough interfacial film. Addition of 2.4% RHJ-1 in water(15% volume) and oil(85% volume) mixture made an emulsion with high electric stability(>1,000 V), high emulsion efficiency(>91.0%) and low free water(<0.7 m L) in a wide range of temperature(50-220 ℃). Sizes of the emulsion droplets were evenly distributed, with no obvious coalescence. Using RHJ-1, a high temperature oil base drilling fluid is formulated with organophilic clay and filter loss reducer etc. The density of this oil base drilling fluid is adjustable between 1.2 g/cm3 and 2.0 g/cm3, and its properties remain stable at 220 ℃.