Study On Organic Alkali Combinational Flooding System For Enhanced Oil Recovery In Heavy Oil Reservoir

The purpose of this paper is to find a suitable organic alkali compound system replacinginorganic alkaline, also has the functions of enhancing oil recovery. In this paper, the floodingperformances of organic alkali and inorganic alkali are compared, including the characteristicof reducing oil-water interfacial tension and the effect of crude oil emulsion. The resultshowed that organic alkali and inorganic alkali solution interfacial tension were relativelylarge compared with crude oil. However, organic alkali showed better performance ofemulsifying crude oil. Furthermore, the interfacial tension of organic alkali and inorganicalkali AS, AP, ASP compound system with crude oil as well as the compatibility with polymerare investigated. Research revealed that organic alkali combination of surfactant with oilinterfacial tension could be reduced to ultra-low. At the same time, ethanolamine/polymercompound system compatibility is very good, and it has little influence on the viscosity ofpolymer. The ethanolamine/surfactant laboratory displacement experiment was carried out.Experiment results showed that mixed system ultimate recovery increased14.1%than usingsingle surfactant flooding, under the condition of two of them had the similar water floodingrecovery. Through comparison between ethanolamine/polymer composite system and singlepolymer laboratory displacement experiment, ethanolamine/polymer compound system ofultimate recovery rate increased5.9%than using single polymer flooding with the waterflooding recovery at similar circumstances. Meanwhile, the microcosmic mechanism oforganic alkaline flooding oil system was discussed. On basis of the micro etching model, theeffect of organic alkali flooding and organic alkali compound system flooding wasinvestigated, which has higher retrieval efficiency displacement efficiency.