【作者】 赵珊珊； 杜娜； 侯万国；

【Author】 Shanshan Zhao;Na Du;Wanguo Hou;The Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University;

【机构】 胶体与界面化学教育部重点实验室山东大学化学与化工学院；

【摘要】 油包水钻井液是一种热力学不稳定体系,在钻井过程中始终存在乳化失效的危险,因此,油基钻井液的核心问题是制备稳定的油包水型乳状液。本文选用EMUL和COAT两种非离子表面活性剂进行复配,以氯化钙盐水为水相,3#白油为油相,通过高速剪切法制备了W/O型乳状液。乳化剂EMUL与COAT吸附在油/水界面上,使界面张力从～40 mN/m降低至～2 mN/m,并且形成具有一定弹性的界面膜,但仅可稳定几个小时。当向乳状液中加入有机土后,其稳定性可显著提升至十几～几十天。通过对相关体系进行界面张力、静置稳定性、液滴粒度分布、界面扩张粘弹性等测试结果的分析,推测有机土部分吸附在界面上,体相与界面的有机土形成三维网状结构,避免了液滴聚结,从而提高了乳状液的稳定性。另外,本文还对含有机土W/O型乳状液的高温高压流变性进行了研究,结果表明乳状液具有较好的抗温、抗剪切能力。更多还原

【Abstract】 The water-in-oil drilling fluid is an unstable thermodynamic system, and there is always the risk of emulsification failure in the drilling process. Therefore, the core problem of water-in-oil drilling fluid is to prepare stable water-in-oil emulsion. In this paper, two kinds of nonionic surfactants, EMUL and COAT, were used for compounding, the calcium chloride brine was used as the water phase and the 3# white oil as the oil phase, prepare the W/O emulsion by high speed shearing. The emulsifier, EMUL and COAT, adsorbed on the oil/water interface, reducing the interfacial tension from over 40 m N/m to about 2 m N/m, and forming an elastic interfacial film, but stable only for several hours. When organic clay was added to the emulsion, the stability can be significantly increased to a dozen to dozens of days. By analyzing the interfacial tension, static stability, droplet size distribution, interfacial dilational viscoelasticity test results, it is speculated that the organic clay is partially adsorbs on the interface, and the organic clay of the bulk phase and the interface is sufficient to form a three-dimensional network structure, which avoids the the droplets coalesce, thereby improving the stability of the emulsion. In addition, the high temperature and high pressure rheological properties of W/O emulsion containing organic clay were also studied, the results show that the emulsion have good temperature and shear resistance.更多还原