胜利正理庄油田特低渗透油藏CO_2驱气窜规律研究

Gas Channeling Rules of CO_2 Flooding in Extra-low Permeability Reservoirs in Zhenglizhuang Oilfield

胜利正理庄油田高89-1块属于特低渗透油藏,不适合注水开发。通过现场开展CO2驱提高采收率先导试验,改善了特低渗透油藏的开发效果;但由于储层非均质性、采出程度以及井网井距的影响,采出气组分中CO2体积分数大于50%,气窜现象严重。通过对气窜的影响因素分析和变化规律研究,采用波动注气、间开间注、控制注入速度等多种方式减缓气窜,提高了CO2的注入效果,平均单井增油0.8t/d,取得了良好的增油效果。

Block Gao 89-1 in Zhenglizhuang Oilfield of Shengli Oilfield belonged to extra-low permeability reservoirs,and was not suitable for waterflooding.A pilot test of CO2 flooding was used to enhance oil recovery in the oilfield,and the effect of extra-low permeability reservoir was improved.However,due to the impact of reservoir heterogeneity and as well as recovery percentages and well spacing,CO2 content in the produced gas was greater than 50%,gas channeling was serious.Through the research of influencing factors and the study of change rules about gas channeling,methods such as fluctuant gas injection,intermittent gas injection and control injection rate are adopted to slow the gas channeling and increase CO2 flooding,the daily oil production of average single well increases 0.8 t /d,good effect of oil increment is obtained.