Лабораторное исследование свойств водорастворимых поверхностно-активных веществ, применяемых в процессах нефтедобычи

Abstract

Background Currently there is the tendency for the structure of oil reserves in existing fields to change. Most deposits are at the late stage of development, which is characterized by high water cutting of the well production, increased share of hardly recoverable reserves and, as a consequence, by lower recovery rate. Aqueous solutions of surfactants can play leading role in increasing oil recovery factor. Exposure to aqueous solutions of surfactants improves the rheological and filtration characteristics of oil by reducing the interfacial tension and improving wetting ability. Aqueous solutions of surfactants improve the process of oil displacement by water from the porous medium. Furthermore, the use of surfactants in the enhanced oil recovery technology is preferable as far as preservation of reservoir properties of productive layers is considered. Aims and Objectives The work has been performed to assess the characteristics of widely used water-soluble nonionic, anionic and biological surfactants for predicting the factors of oil-saturated reservoir development. Objective of the research is to compare performance of nonionic surfactants (OP-10, AF9-12), anionic surfactant (sulfonol) and biological surfactant (KSHAS-M). Methods Surface tension and interfacial tension of aqueous surfactant solutions was determined using ST-1 stalagmometer. To select the input data for predicting the development of deposits, of greatest interest are research results obtained during oil displacement from natural sandstone, as most approaching to the real conditions. In this connection, quartz sand adsorption of a surfactant was studied and determined under static conditions. The contact angle on the «surfactant solution - air» boundary was determined using the contact angle computing program. Conclusion The studies involved a number of indicators that characterize the important properties of surfactants: surface and interfacial tension, adsorption capacity, wetting angle, displacing properties. Experiments conducted in the laboratory show that biosurfactants are similar in their effect to the synthetic surfactants, but have more pronounced physical and chemical properties, are ecologically safe, and most promising for extraction of hardly recoverable reserves using flooding. Biosurfactant KSHAS-M possesses advantages in terms of superficial and interfacial tension, adsorptive capacity, values of interfacial angle, extrusive properties.