石油地质与工程2025，Vol.39Issue(5)：9-14,6.DOI:10.26976/j.cnki.sydz.202505002
潜山近临界强挥发油藏伴生气回注提高采收率研究
Study on associated gas recycling for enhanced oil recovery in near-critical strongly volatile oil reservoirs of buried hills:a case study of BZ Oilfield in the Bohai Sea
摘要
Abstract
The BZ Oilfield in the Bohai Sea is a buried hill strongly volatile oil reservoir.The formation flu-ids exhibit near-critical characteristics,including high gas-oil ratio,large volume factor,and small dew-point pressure difference,leading to complex phase behavior of fluids and gas injection seepage laws in dual-media reservoirs under high-temperature and high-pressure conditions.To scientifically guide the formulation of the oilfield gas injection development plan,minimum miscibility pressure(MMP)tests and long-core cyclic gas injection displacement experiments were conducted to analyze the impact of gas injection on oil displacement efficiency.Meanwhile,a dual-media compositional model was established to optimize gas injection parameters for fractured near-critical strongly volatile oil reservoirs.The experimen-tal results show that when the formation pressure exceeds 35.79 MPa,the injected gas achieves good misci-bility with the formation crude oil.In the initial injection stage,the oil recovery factor significantly increases with the injected gas volume,but the growth rate slows down notably after the injected volume reaches 1.0 PV,with the ultimate oil displacement efficiency reaching 75.75%.Numerical simulation optimization re-sults indicate that gas injection development can enhance the recovery factor of near-critical volatile oils.It is recommended that the associated gas recycling ratio for the BZ Oilfield be 80%with a recycling period of 15 years,under which the oil recovery factor of gas injection development can reach 28.4%.The gas injec-tion parameters obtained through miscible displacement experiments and numerical simulation optimization have been successfully applied to the formulation and implementation of the gas injection plan for the BZ Oilfield.The research results provide references for gas injection development and enhanced oil recovery in similar oil and gas fields.关键词
强挥发性油藏/双重介质/混相/注气/回注率/数值模拟Key words
strongly volatile oil reservoir/dual media/miscibility/gas injection/injection ratio/numerical simulation分类
能源科技引用本文复制引用
姜永,郑华,宋新飞..潜山近临界强挥发油藏伴生气回注提高采收率研究[J].石油地质与工程,2025,39(5):9-14,6.基金项目
中海石油(中国)有限公司综合科研项目"海上典型油气藏天然气/CO2协同驱替提高油气采收率研究"(KJZH-2024-2205). （中国）
