油基钻井液中乳状液及有机土分散体系的稳定性

发布时间：2018-01-16 07:08

本文关键词：油基钻井液中乳状液及有机土分散体系的稳定性　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：油基钻井液主要组成包括矿物油、盐水以及适量的乳化剂、润湿剂、有机土以及加重剂等处理剂。相比于水基泥浆,油包水乳化钻井液的抑制性和耐温能力更强,在复杂地层中钻井可以消除阻卡,能更有效的保护油气层,减少井下事故发生。而且体系性能比较稳定,很少需要维护处理,从而在水敏井、超深井或地热井钻井中广泛应用。油基钻井液为热力学不稳定体系,所添加的各种处理剂都会对其稳定性产生影响,并且还存在有机土在油相中增粘提切性能较差等问题。本文依据以上背景,较为系统的研究了乳化剂、润湿剂和有机土等处理剂对油包水乳液稳定性的影响规律。还通过原位改性海泡石有效增粘白油,且高温对改性海泡石/白油体系流变性能影响较小。测定了乳化剂、润湿剂、提切剂等添加剂对有机土/白油分散体系流变性能的影响,并得到有机土增稠白油的方法。本文所论述内容主要分为以下两个部分:1、油基钻井液处理剂对乳液稳定性的影响通过红外光谱等表征手段分析了四种乳化剂结构中的主要官能团,并使用界面张力仪测得乳化剂-3、乳化剂-4相比乳化剂-1、乳化剂-2降低油水界面张力的能力较强;偏光显微镜可以观察到油包水乳液的微观形貌,发现将含有脂肪酸及烷基磺酸的衍生物表面活性剂作为主乳化剂,酰胺基和羟基的表面活性剂作为辅乳化剂,二者复配使用,形成的界面膜更致密,降低油水界面张力能力更强,制备的盐水滴粒径更小,体系更稳定;通过动态界面流变测得润湿剂同样可以在油水界面吸附,但制备的乳液抗温性能较差;通过激光共聚焦显微镜观察到有机土颗粒能够在油水界面吸附,协助乳化剂增强界面膜强度,有利于提升乳状液体系的稳定性。2、油基钻井液处理剂对有机土/白油体系流变性能影响通过热重分析及HAAKE流变分析了有机土物理化学性能,发现改性剂含量较高的有机土,增强体系粘度的效果较好;利用季铵盐对无机纤维海泡石在白油中进行原位改性,相比于商业有机土不仅增粘提切效果好,而且所增稠的白油流变性能受温度的影响较小;通过HAAKE流变仪对含有不同处理剂的有机土分散体系进行表征,可以发现乳化剂、润湿剂、提切剂等表面活性剂也可吸附于有机土固相颗粒表面,影响颗粒的亲疏水性以及颗粒之间的相互作用,从而对体系流变性能产生影响。支链结构的表面活性剂能有效降低有机土/白油体系的粘度,如:乳化剂-1、乳化剂-3、聚异丁烯内酯等,润湿剂在有机土分散体系中具有增粘作用,同时添加润湿剂与提切剂可以更有效提高体系的粘度。
[Abstract]:Oil-base drilling fluid mainly consists of mineral oil, brine and proper amount of emulsifier, wetting agent, organic soil and weighting agent, etc. Compared with cement slurry, oil based drilling fluid is composed of mineral oil, salt water and suitable emulsifier, wetting agent, organic soil and weighting agent. The oil-in-water emulsified drilling fluid has stronger inhibition and temperature resistance. Drilling in complex formations can eliminate the blocking, protect oil and gas layers more effectively, reduce downhole accidents, and the system performance is relatively stable. There is little need for maintenance treatment, so it is widely used in water sensitive wells, ultra-deep wells or geothermal wells. The oil-base drilling fluid is a thermodynamically unstable system, and all kinds of additives will affect its stability. And there are still some problems such as poor viscosity and shear properties of organic soil in oil phase. Based on the above background, the emulsifier is studied systematically in this paper. The effect of wetting agent and organic soil treatment agent on the stability of oil-in-water emulsion was studied. The in-situ modification of sepiolite was also used to effectively increase the viscosity of white oil. The rheological properties of modified sepiolite / white oil system were not affected by high temperature. The effects of emulsifier, wetting agent, slashing agent and other additives on rheological properties of organic soil / white oil dispersion system were determined. The method of thickening white oil in organic soil is obtained. The content of this paper is divided into two parts: 1. Influence of oil based drilling fluid treatment agent on emulsion stability the main functional groups in four emulsifiers were analyzed by means of infrared spectroscopy and emulsifier 3 was measured by interfacial tension meter. Compared with emulsifier-1, emulsifier-4 has stronger ability to reduce the interfacial tension between oil and water. The micromorphology of water-in-oil emulsion was observed by polarizing microscope. It was found that the surfactant containing fatty acid and alkyl sulfonic acid was used as the main emulsifier and the surfactant containing amide group and hydroxyl group as co-emulsifier. The interfacial film formed is denser, the interfacial tension of oil and water is reduced more, the diameter of salt and water droplets is smaller and the system is more stable. It was found that the wetting agent could also be adsorbed at the oil-water interface by dynamic interfacial rheology, but the prepared emulsion had poor temperature resistance. It was observed by laser confocal microscope that the organic soil particles could adsorb at the oil-water interface, which helped the emulsifier to enhance the strength of the interfacial film and to improve the stability of the emulsion liquid system. 2. Effect of oil based drilling fluid treatment agent on rheological properties of organic soil / white oil system the physical and chemical properties of organic soil were analyzed by thermogravimetric analysis and HAAKE rheology. It was found that organic soil with high content of modifier was found to be organic soil. The effect of enhancing the viscosity of the system is better; The in-situ modification of inorganic fiber sepiolite in white oil by quaternary ammonium salt is better than that of commercial organic soil, and the rheological property of thickened white oil is less affected by temperature. HAAKE rheometer was used to characterize the organic soil dispersion system with different treatment agents. It can be found that surfactants such as emulsifier, wetting agent and slashing agent can also be adsorbed on the solid particle surface of organic soil. The viscosity of organic soil / white oil system can be effectively reduced by the surfactant with branched chain structure, such as emulsifier 1, which affects the hydrophobicity of particles and the interaction between particles. Emulsifier-3 polyisobutene lactone and wetting agent can increase the viscosity of the system by adding wetting agent and cutting agent.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE254

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