Abdul Habib Nor Saiful Hafiz, Yunus Robiah, Rashid Umer, Taufiq-Yap Yun H, Abidin Zurina Zainal, Syam Azhari Muhammad, Irawan Sonny
Department of Chemical and Environmental Engineering, Engineering Faculty, Universiti Putra Malaysia.
J Oleo Sci. 2014;63(5):497-506. doi: 10.5650/jos.ess13220. Epub 2014 Apr 9.
The use of vegetable oil-based ester as a base fluid in synthetic drilling fluid has become a trend in drilling operations due to its environmental advantages. The transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (2EH) produced 98% of palm oil-based ethylhexyl ester in less than 30 minutes. Since the transesterification reaction of POME with 2EH is a reversible reaction, its kinetics was studied in the presence of excess EH and under vacuum. The POME-to-EH molar ratio and vacuum pressure were held constant at 1:2 and 1.5 mbar respectively and the effects of temperature (70 to 110°C) were investigated. Using excess of EH and continual withdrawal of methanol via vacuum promoted the reaction to complete in less than 10 minutes. The rate constant of the reaction (k) obtained from the kinetics study was in the range of 0.44 to 0.66 s⁻¹ and the activation energy was 15.6 kJ.mol⁻¹. The preliminary investigations on the lubrication properties of drilling mud formulated with palm oil-based 2EH ester indicated that the base oil has a great potential to substitute the synthetic ester-based oil for drilling fluid. Its high kinematic viscosity provides better lubrication to the drilling fluid compared to other ester-based oils. The pour point (-15°C) and flash point (204°C) values are superior for the drilling fluid formulation. The plastic viscosity, HPHT filtrate loss and emulsion stability of the drilling fluid had given acceptable values, while gel strength and yield point could be improved by blending it with proper additives.
由于植物油基酯具有环境优势，在合成钻井液中使用其作为基础液已成为钻井作业的一种趋势。棕榈油甲酯（POME）与2-乙基己醇（2EH）的酯交换反应在不到30分钟内生成了98%的棕榈油基乙基己酯。由于POME与2EH的酯交换反应是可逆反应，因此在过量EH存在和真空条件下对其动力学进行了研究。POME与EH的摩尔比和真空压力分别保持在1:2和1.5毫巴不变，并研究了温度（70至110°C）的影响。使用过量的EH并通过真空持续抽出甲醇可促进反应在不到10分钟内完成。动力学研究得到的反应速率常数（k）在0.44至0.66 s⁻¹范围内，活化能为15.6 kJ·mol⁻¹。对以棕榈油基2EH酯配制的钻井液润滑性能的初步研究表明，该基础油有很大潜力替代合成酯基油用于钻井液。与其他酯基油相比，其高运动粘度为钻井液提供了更好的润滑。倾点（-15°C）和闪点（204°C）值对于钻井液配方来说较为优异。钻井液的塑性粘度、高温高压滤失量和乳液稳定性给出了可接受的值，而凝胶强度和屈服点可通过与适当添加剂混合来提高。
