钻井液用微乳液润滑剂NE的研究与应用

当前钻井液用液体润滑剂存在抗温性能差、制备工艺复杂、起泡率及荧光级别高等难题，制约了水平井钻井井眼的有效延伸，降低了钻井效率。结合胶体与界面化学基础理论，以液态石蜡、Span80及Tween80等为原料，研发出一种微乳液润滑剂NE，并通过室内实验评价了其性能，分析了其主要润滑机理。研究结果表明，NE稀释后形成的纳米液滴呈正电性，平均粒径在187～258 nm之间；加入2.0% NE后膨润土浆的润滑系数降低率为83.8%，泥饼黏附系数降低率为74.2%；NE可抗160℃高温，耐温性良好，荧光级别为2级，起泡率低，与钻井液配伍性良好；基于吸附作用与纳米效应，NE可良好地吸附在矿物与金属钻具表面，大幅提高润滑效率。现场应用结果表明，NE可大幅降低钻柱扭矩与摩阻，减少卡钻事故发生频率，满足水平井段钻井液润滑性的技术要求。 

Study and Application of a Drilling Fluid Microemulsion Lubricant NE

Deficiencies have been found of the drilling fluid lubricants used presently, such as poor high temperature stability, complex preparation process, severe foaming and high level of fluorescence etc. These deficiencies have hindered drilling horizontal wells with longer horizontal displacement, and decreased drilling efficiency. A new micro emulsion lubricant, NE, has been developed with liquid paraffin, Span80 and Tween80 etc. based on the basic principle of colloid and interface chemistry. Laboratory study on the performance of NE showed that the nanophase liquid drops formed by the dispersed NE are positively charged, and the average diameter of the drops is between 187 nm and 258 nm. A bentonite slurry treated with 2.0% NE has its coefficient of friction reduced by 83.8%, and sticking coefficient of mud cake reduced by 74.2%. NE has good high temperature stability; it performs effectively at 160℃. NE has fluorescence level of 2 and is resistant to foaming. NE is compatible very well with drilling fluids. NE can firmly adsorb on the surfaces of minerals and metallic drilling tools through nano effect, thereby greatly enhance the lubricating efficiency of the drilling fluid. Field application has demonstrated that NE greatly reduced torque and friction of drilling tools and minimized the occurrence of pipe sticking, satisfying the lubricity requirement imposed on drilling fluid in horizontal drilling.