低渗透油藏CO2混相驱提高采收率试验

大多数低渗透油藏注水开发效果差,为了验证CO2混相驱在此类油藏的适用性,掌握其提高采收率的程度,以大庆榆树林油田为依托,进行了原油的细管试验与微观试验、天然岩心的驱油试验以及油藏的数值模拟研究,确定了CO2与榆树林油田原油的最小混相压力,试验与数值模拟测试了不同驱替方式在天然岩心上的采收率,二者非常吻合。试验表明:CO2混相驱可以应用于榆树林油田;天然岩心试验无水混相驱可以提高采收率19个百分点以上,水气交替可以提高采收率10~19个百分点;注入1个气体的合适段塞可以减少水对混相的影响,更大程度提高采收率。该研究表明CO2混相驱可提高低渗透油藏开发效果。

RESEARCH ON CO2 MISCIBLE FLOODING TO ENHANCE OIL RECOVERY IN LOW PERMEABILITY RESERVOIR

Basis on the development problems of Yushulin low permeability oil field,and in order to verify suitability of CO_2 Miscible Flooding to this kind of reservoir,a series of experiment about CO_2 displacement in slime tube,core and numerical simulation were developed,obtained minim miscibility pressure of Yushulin Oilfield,the experiment and numerical simulation results of recovery rate with different displacement in core can get well coincidence,and get flowing conclusion: the CO_2 displacement can be used in Yushulin Oilfield,anhydrous miscible flooding in core can enhance 19% of recovery ratio and gas-water alternative displacement can improve 10% to 19%.Injection a suitable volume of gas can decrease the affection of water and enhance oil recovery ratio.