一种低黏高切油基钻井液体系

针对传统油包水钻井液黏度高、切力低、携岩能力差的问题,合成了一种Gemini主乳化剂,其与辅乳化剂有较好的协同效应,钙皂分散性好,兼具润湿功能,在2.0%~3.5%的低加量下具有好的乳化能力。研制出了密度在1.0~2.0 g/cm3之间、抗温达170℃的低黏、高切油基钻井液。室内研究结果表明,该钻井液密度为1.00~1.70 g/cm3时,塑性黏度小于40 m Pa s,动塑比为0.35~0.50 Pa/m Pa s,具有低黏高切的特点;破乳电压在800 V以上;抗水达15%,抗钻屑达10%,并且润滑性能好,密度在2.0 g/cm3以下时润滑系数小于0.085。在焦页54-1HF井水平段的应用表明,该钻井液性能稳定,具有突出的低黏高切流变特性,破乳电压高,保证了施工顺利、井壁稳定、井眼通畅。

A Low Viscosity High Gel Strength Oil Base Drilling Fluid

A new emulsifier was developed to mitigate the problems of oil base drilling fluid such as high viscosity and low gel strength which are negative to the suspension and carrying of drilled cuttings. An oil base drilling fluid was formulated with this new emulsifier. The properties of this mud were as follows: density 1.0-1.7 g/cm3, plastic viscosity≤40 mPa·s, ratio of yield point to plastic viscosity 0.35-0.50 Pa/mPa·s, and electric stability≥800 V. This mud had good rheology and was tolerant to contamination by water to 15%, and drilled cuttings to 10%. This mud had been successfully used in Well Jiaoye54-1HF.