油基钻井液用乳化剂油/水界面吸附及对乳液结构的影响

Oil-water Interface Adsorption of Emulsifier for Oil-based Drilling Fluid and the Influence on Emulsion Structure

在油基钻井液中,乳化剂在油/水界面的吸附行为对乳化稳定性及乳化机理影响极大。利用界面扩张流变技术研究了油基钻井液用主乳化剂PF-BIOEMUL与油基钻井液用辅乳化剂PF-BIOCOAT对油/水动态界面张力及界面黏弹性的影响,并考察了PF-BIOEMUL与PF-BIOCOAT配制乳液的微观流变性。研究表明,PF-BIOEMUL的主要功能是提供弹性模量,提高油/水界面膜强度高,最佳加量为2.0%。PF-BIOCOAT的主要功能是提供黏性模量,降低油/水界面张力,最佳用量为1.5%。PF-BIOEMUL和PF-BIOCOAT可以同时吸附到油/水界面上,保证了乳化体系既具有较低的油/水界面张力,又有较好的界面膜稳定性,所形成的乳液具有三维网状结构,稳定性良好。这些研究为油基钻井液体系稳定性研究提供了理论基础。图11参21。

The interfacial adsorption behavior of oil and water has great influence on emulsification stability and emulsification mechanism in oil-based drilling fluid.In this paper,the dynamic interfacial tension change and interfacial viscoelasticity of oil-based drilling fluid main emulsifier PF-BIOEMUL and oil-based drilling fluid auxiliary emulsifier PF-BIOCOAT at the oil/water interface were studied by using interfacial dilatational rheology technology,and the micro-rheology of emulsion prepared by PF-BIOEMUL and PF-BIOCOAT was also studied.The results showed that the main function of PF-BIOEMUL was to provide elastic modulus and improve the strength of oil/water interface membrane,and the optimum concentration was 2.0%.The main function of PF-BIOCOAT was to provide viscous modulus and reduce the interfacial tension between oil and water,and the optimum concentration was 1.5%.PF-BIOEMUL and PF-BIOCOAT could be adsorbed on the oil/water interface at the same time,which not only ensured the composite emulsifier had low oil/water interface tension,but also had better interfacial film stability,and the formed emulsion had a three-dimensional network structure.All these studies provide theoretical basis for stability research of oil-based drilling fluid system.