无土相油基钻井液的研究与应用  

Study on and Application of Clay-free Oil Base Drilling Fluid

作　　者：吴满祥[1,2] 刘伟[1,2] 牟杨琼杰[3] 王京光 赵海锋[1,2] 王勇强[1,2] 

机构地区：[1]低渗透油气田勘探开发国家工程实验室 [2]川庆钻探工程有限公司钻采工程技术研究院 [3]川庆钻探工程有限公司长庆钻井总公司

出　　处：《钻井液与完井液》2014年第6期21-23,96,共3页Drilling Fluid & Completion Fluid

基　　金：中石油集团公司科技项目"西部大庆建设长庆钻完井整体提速及压裂一体化技术研究与现场试验"(2013T-0105-001)

摘　　要：为解决无土相油基钻井液电稳定性差、油水极易分层的问题,研发出一种兼具润湿作用的新型复合型乳化剂G326-HEM,该剂以由高分子量脂肪酸、有机伯胺为主要原料合成的脂肪酸酰胺作主剂,该主剂具有亲油及亲水2个基团,可以在油水界面形成具有一定黏弹性的界面膜,显著降低界面张力;辅助增效剂为优选出的天然植物脂肪酸,可与体系中过量的石灰反应,生成的产物可在油水界面锲行排列,配合主剂形成油包水乳状液。以G326-HEM为乳化剂配制的无土相油基钻井液性能稳定,抗温可达180℃,密度可达2.50 g/cm3,可抗10%Na Cl盐水或15%岩屑的污染,乳化稳定性好,用矿物油或合成油均可配制。在ZT-21井获得了成功应用,解决了以往含土相油基钻井液在高密度条件下暴露出的流变性差、起下钻不畅、易发生压差卡钻、易诱发井漏等难题。指出,无土相油基钻井液由于当量循环密度低,在高密度条件下相对于含土相油基钻井液更具优势,尤其在高压易漏地层具有更好的应用效果。Clay-free oil base drilling fluid has low electric stability which results in easy water oil separation. To formulate a clay-free oil base drilling fluid, an emulsifier, G326-HEM was developed with high molecular weight fatty acids and primary amines as main raw material. G326-HEM also shows some wettability, and has organophilic groups and organophobic groups, enabling it to form visco-elastic film at the interface between oil and water, thereby reducing the surface tension of the system. A natural vegetable fatty acid was used as the secondary extender to neutralize the excessive lime in the system. Oil base drilling fluid using G326-HEM as the emulsifier was used to drill Well ZT-21, and it was a success. This mud had low equivalent circulation density, and since being clay-free, it was much more beneficial to oil base drilling fluid containing clay, especially when high pressure, lost circulation zones are being drilled.

关 键 词：乳化剂 无土相油基钻井液 高密度钻井液 稳定性 当量循环密度 

分 类 号：TE254.3[石油与天然气工程—油气井工程]