游园沟油田注气驱化学分析及提高采收率室内研究

Chemical Analysis of Gas Injection in Low Permeability Oilfield and Laboratory Study on Improving Oil Recovery

针对青海油田采油一厂游园沟油田三四层系低渗透的特性开展了注气驱化学分析及采收率实验研究,阐释了CO_(2)气驱过程及提高采收率化学作用机理,通过室内相态实验确立了地层原油的物理化学特征参数,结合地层流体膨胀及驱替实验分析了原油膨胀系数变化规律,评价了低渗透油藏CO_(2)气驱最小混相压力,结果显示目标地层只能为CO_(2)非混相驱,且在地层压力下CO_(2)气驱采收率为48.52%。

Chemical analysis and oil recovery experiments on gas injection flooding in low-permeability oil fields were carried out,the process of CO_(2) gas flooding and the chemical mechanism of improving oil recovery were elucidated.Through indoor phase state experiments,the physical and chemical characteristic parameters of formation crude oil were established,and the variation law of crude oil expansion coefficient was analyzed based on formation fluid expansion and displacement experiments.The minimum miscibility pressure of CO_(2) gas flooding in low-permeability oil reservoirs was evaluated.The results showed that the target formation could only be CO_(2) immiscible flooding,and the CO_(2) gas flooding recovery rate was 48.52%under formation pressure.