CO_2驱油泡沫防气窜技术实验研究

An Experimental Study on Anti-channeling Technology with Foam in CO_2 Flooding

腰英台油田CO2驱油先导试验中CO2过早气窜,降低波及体积,影响区块产能。采用岩芯切割技术制作了低渗透裂缝性岩芯模型,通过岩芯驱替实验研究了不同CO2泡沫注入方式对低渗透裂缝性岩芯封堵能力的影响以及水驱或气驱后CO2泡沫驱提高采收率的效果。实验结果表明：CO2泡沫能增加流体在裂缝中的流动阻力,有效降低驱替液流度,阻力因子在4680;泡沫在裂缝中存在启动压力,它将影响泡沫起始阶段的流动。对于水驱和气驱之后采用泡沫驱的岩芯,采收率分别增加了26%和35%,揭示了泡沫提高低渗透裂缝性油藏采收率机理。

In the pilot test of CO2 flooding in Yaoyingtai Oilfield,early CO2 channeling decreased its sweeping volume and production capacity.Low permeability fractured core models were generated by core cutting technique.The foam blocking ability and flooding performance were measured by core flooding experimental apparatus and the effects of different foam injection schemes on foam plugging and EOR results of foam displacement following water and gas flooding were conducted.The experiment results show that CO2 foam can increase fluid flow resistance in the fracture,reduce liquid motility effectively with resistance factors between 4680;there is a foam apparent viscosity in the fracture that has an impact on the initial flow of foam;for the oil saturated fractured cores flooded by water and gas,oil recovery was increased by 26%and 35%respectively and the mechanism of CO2 foam EOR in low permeability fractured reservoirs are revealed.