胜利油田CO_(2)高压混相驱油与封存理论技术及矿场实践

CO_(2) high-pressure miscible flooding and storage technology and its application in Shengli Oilfield,East China

针对胜利油田开展CO_(2)驱油与封存面临的原油轻烃含量低混相难、储层非均质性强波及效率低、易气窜全过程调控难等问题,通过室内实验、技术攻关和矿场实践,形成CO_(2)高压混相驱油与封存理论及关键技术。研究发现,提高地层压力至1.2倍最小混相压力之上,可以提高原油中的中重质组分混相能力,增大小孔隙中的原油动用程度,均衡驱替前缘,扩大波及体积。通过超前压驱补能实现快速高压混相,采用梯级气水交替、注采耦合、多级化学调堵等技术全过程动态调控渗流阻力,实现采收率与封存率的协同最优。研究成果应用于高89-樊142 CCUS(二氧化碳捕集、利用与封存)示范区,区块日产油由254.6 t提高至358.2 t,预计实施15年可提高采出程度11.6个百分点,为CCUS规模化应用提供理论和技术支撑。

There are various issues for CO_(2) flooding and storage in Shengli Oilfield,which are characterized by low light hydrocarbon content of oil and high miscible pressure,strong reservoir heterogeneity and low sweep efficiency,gas channeling and difficult whole-process control.Through laboratory experiments,technical research and field practice,the theory and technology of CO_(2) high pressure miscible flooding and storage are established.By increasing the formation pressure to 1.2 times the minimum miscible pressure,the miscibility of the medium-heavy components can be improved,the degree of oil production in small pores can be increased,the displacing front developed evenly,and the swept volume expanded.Rapid high-pressure miscibility is realized through advanced pressure drive and energy replenishment,and technologies of cascade gas-water alternating,injection and production coupling and multistage chemical plugging are used for dynamic control of flow resistance,so as to obtain the optimum of oil recovery factor and CO_(2) storage factor.The research results have been applied to the Gao89-Fan142 in CCUS(carbon capture,utilization and storage)demonstration site,where the daily oil production of the block has increased from 254.6 t to 358.2 t,and the recovery degree is expected to increase by 11.6 percentage points in 15 years,providing theoretical and technical support for the large-scale development of CCUS.