低渗透油藏CO 2 驱过程中含水率变化规律 - 吉林大学学报.PDF

41 4 ( ) Vol. 41 No.4 2011 07 Journal of Jilin University( Earth Science Edition) July 2011 低渗透油藏C 2 驱过程中含水率变化规律 俞宏伟, 杨思玉, 李 实, 杨永智 / , 100083 : 通过国内外多 个油田水驱后实施C 2 驱的矿场实例研究, 发现注入 C 2 后很多油井存在含水 率下 的现象; 这种现象发生在C 2 驱的整 个开发阶段, 包括注气初期阶段C 2 未到达生产井生产井见 气阶段以及高气油比阶段重点讨论了生产井见气前的开发规律,在该阶段油藏内以油水两相渗流为主, 不受三相渗流作用的影响通过现场动态反应并结合室内细管和长岩心实验, 揭示了C 2 与油水2 种介 质的相互作用, 得到了两 个结论: 第一是始于低含水阶段的 C 2 驱过程中气体穿越地层水驱替地层油到达 生产井; 第二是始于高含水阶段的C 2 驱替规律在不同级别低渗透岩心中的差异非常明显: 对于特低渗岩 心,C 2 突破前的采出程度占C 2 驱总采出程度的73.27%, C 2 突破后的采出程度占26. 73%, 对于 一般 低渗岩心, C 2 突破前的采出程度仅占C 2 驱总采出程度的 16.72%, 而 C 2 突破后的采出程度占到了 C 2 驱总采出程度的 83.28% : C 2 驱;低渗透; 室内实验;含水; 开发规律; 油气 : P618. 13 : A : 1671-5888(2011)04-1028-05 Rules of Water Cut Variation in Low Permeability Oil Reservoir CO Flooding Process 2 YU Hong-wei, YANG S-i yu, LI Shi, YANG Yong-zhi State Key Laboratory of Enhanced Oil Recovery/ Research I nstitute of Petroleum Exp loration and Develop ment, Petro hina, Beij ing 100083, hina Abstract: T hrough the study of many domestic and abroad field examples of C 2 flooding after water flooding, it is discovered that after the injection of C 2 , the water cut of many production wells decreases sharply, and this phenomenon happens across the whole development phase, including the early stage of C 2 injection which the C 2 displacing front doesnt reach production wells, the stage of little gas producing,and the stage of high gas-oil ratio. We take emphasis on discussing the development rules of low permeability reservoir beforethe breakthrough of C 2 , and on this stage oil-water two-phase fluid flow is themain flow type, and three-phaseflow