摘要
针对特低渗透油藏水相难以有效注入、水气交替难以有效实施的问题,提出采用周期注气来改善特低渗透油藏注CO2驱油效果。首先通过与其他注入方式的对比,分析周期注气的优缺点,指出其比较适合特低渗透油藏。然后采用数值模拟的方法,研究周期注气改善驱油效果的机理,分析认为周期注气能够有效改善流度比,扩大CO2的波及体积,降低粘性指进的影响。最后将周期注气应用到特低渗透油藏芳48和树101区块的方案编制中,数值模拟结果表明,与连续注气相比,周期注气可以有效提高CO2的换油率,减缓油井气窜,最终提高采收率;并且在现场生产过程中,周期注气可以明显降低油井油气比上升速度,改善油藏开发效果。
In allusion to the problems of difficult water injection in extra-low permeability reservoirs and difficult water and gas alternation,it was proposed that cyclic gas injection was used to improve the CO2 displacement effect.First it was compared with other injection patterns,the advantages and disadvantages of cyclic gas injection were analyzed,numerical simulation method was employed to study the mechanism of cyclic gas injection.It was considered that it could expand swept volume of CO2 and reduce the influence of viscous fingering.Finally,the cyclic gas injection is applied in the reservoir engineering plan of low permeability reservoir Fang 48 and Block Shu 101.The results of numerical simulation show that comparing with continuous gas injection,the cyclic gas injection can improve oil draining rate,delay the time of gas channeling,and improve oil recovery.In the process of oil field production,the rate of gas-oil ratio increase can be reduced and displacement effects can be improved by cyclic gas injection.
出处
《石油天然气学报》
CAS
CSCD
北大核心
2010年第6期131-134,共4页
Journal of Oil and Gas Technology
基金
国家科技支撑计划课题(2006BAB03B06)
关键词
特低渗透油藏
二氧化碳驱
注入方式
周期注气
extra-low permeability reservoir
CO2 displacement
injection pattern
cyclic gas injection
