西五二挥发性油藏注氮和富气驱室内评价研究

选用柯428井分离器油气样按目前压力等于泡点压力进行配样,用柯233井的储层实际岩心进行了长岩心测试注氮气和烃类气评价,膨胀试验、细管试验及不同注入气对岩心驱替效率的影响研究。研究表明:注氮气比注烃类气更易使泡点升高,膨胀能力不如烃类气强;所选烃类气、氮气和原油在目前地层压力下均不能混相;岩心试验表明烃类气越富或注入压力越高均会明显影响注气后的最终驱油效率,同目前油藏衰竭式开采相比,注N2可提高驱油效率6.08%,注富气可提高18.8%~21.31%,表现出较强的注气潜力。

LAB RESEARCH OF NITROGEN AND RICH GAS INJECTION IN XI-52VOLATILE RESERVOIR

The main research of this paper includes evaluation of nitrogen and hydrocarbon gas injection in real long core, expansion test, slim tube test and flooding efficiencies of different gases. All the experiments are conducted upon long real formation core from Ke-233 well by using synthetic fluids of separate oil and gas samples from Ke-428 well compounded at bubble point pressure. The results show that it is harder for hydrocarbon gas with higher expansion ability to increase bubble point pressure than nitrogen. But both selected hydrocarbon gas and nitrogen can not get miscible with oil at present formation pressure. It is also demonstrated in the core test that with the richer hydrocarbon gas and higher injection pressure, the ultimate displacement efficiency is more obvious. Compared with the present depletion production, nitrogen injection can increase the efficiency by 6.08%, rich gas injection by 18.8%-21.31%.The results indicate a strong potential for gas injection.