海上“三低”油藏CO_2注气开发适应性评价

Adaptability Evaluation of CO_2 Gas Injection Development for “Three Low” Offshore Oil Reservoir

针对南海西部海域油田"三低"特征(即电阻率低、含油饱和度低和渗透率低),在开发过程中由于束缚水饱和度高和泥质含量高,水敏性强,面临注水困难和地层能量补充的问题。在充分调研国内外CO2驱室内试验研究和注气开发适应性评价的基础上,以油藏为例,完成了CO2注气室内试验和油藏数值模拟研究,并在此基础上进行了CO2注气开发适应性评价。通过数值模拟研究,对衰竭式开发、连续注气和WAG水气交替注入两种驱替方式进行了方案设计和对比分析,结果表明该油田CO2注气开发具有很好的适应性,WAG水气交替注入能进一步提高油田开发的采收率。

In view of the“three low”characteristics（i.e.,low resistivity,low oil saturation and low permeability）of Oilfield in western South China Sea,water injection and energy supplement difficulties exist in the development process due to high irreducible water saturation and high shale content and strong water sensitivity. Based on laboratory researches and adaptability evaluations of gas injection of CO2 at home and abroad,and by taking reservoir as an example,laboratory experiment of CO2 gas injection and reservoir numerical simulation are finished,and theCO2 gas injection development adaptability evaluation is done on this foundation. A comparison among the depletion type development,continuous gas injection and WAG displacement through numerical simulation,the result shows CO2 gas injection development has good adaptability,and WAG can further improve the oil recovery of oilfield development.