超临界CO_2增稠剂研究进展

CO2驱是目前国内外提高油藏采收率的重要方法之一,但由于存在不利的流度比、地层非均质性、天然或人工裂缝等因素,易造成注入CO2流体发生气窜。常用的提高CO2驱波及效率的方法有气水交替驱、CO2泡沫驱和聚合物冻胶驱等,通过在超临界CO2中加入增稠剂,也可提高CO2驱波及系数,提高原油采收率。文中对国内外研究的各种CO2增稠剂进行了综述与评价,重点介绍了常见聚合物、小分子、含氟聚合物以及不含氟表面活性剂等各种类型增稠剂,同时从相行为、相对黏度测定方面介绍了CO2增稠评价方法,对提高CO2驱波及效率的超临界CO2增稠剂的发展方向提出了建议。

Research advance in supercritical CO2 thickeners

At present,CO2 miscible flooding has been an important method to improve oil recovery factor in the world.However,due to the irrational mobility ratio among gas,oil and formation salt water,formation heterogeneity and natural or artificial fracture,the supercritical CO2 flows through the formation and gas channeling occurs.Common methods of improving the sweep efficiency of CO2 flooding include WAG,CO2 foam and polymer gel.Addition of thickener in supercritical CO2 can be used for improving the sweep efficiency of CO2 flooding to enhance the oil recovery.This paper reviewed and evaluated different kinds of supercritical CO2 thickeners and evaluation methods of CO2 thickening studied by foreign researchers.All kinds of thickeners such as common polymer,small molecular nitrogen polymer and the surfactant without nitrogen are mainly introduced.At the same time,the evaluation methods of CO2 thickening are also introduced from phase behavior and relative viscosity determination.Finally,some suggestions on development direction of supercritical CO2 thickeners were put forward.