低张力泡沫驱提高采收率的三维物理模拟研究*

Three-Dimensional Physical Simulation Research of Enhanced Oil Recovery in Low Tension Foam Flooding

元福卿 李 冉 李兆敏 李驰 李松岩 李金洋 高 强

YUAN Fu-Qing LI Ran LI Zhao-Min LI Chi LI Song-Yan LI Jin-Yang GAO Qiang

利用三维人工填砂和胶结物理模型，对低张力泡沫体系在模拟胜利油田油藏条件下的压力场、饱和度场变化特征以及开采特征和剩余油分布规律进行了研究。结果表明，低张力泡沫驱可以提高模型整体的注入压力，起到调堵、分流改善地层非均质性的效果。注入初期由于气体上浮作用不明显，在毛管力和黏滞力作用下，低张力泡沫主要赋存于模型中下层，模型中下部的压力值相对稍高。后期在气体上浮作用和泡沫黏滞力的综合作用下，压力曲线变化较平缓，泡沫在模型中均匀分布，并能像活塞一样均匀向前推进，模型中的剩余油主要滞留聚集在出口端，入口附近的驱替效果最好。在泡沫调驱的主导作用以及低张力洗油和气体上浮的共同促进下，高渗层和低渗层的驱油效果较明显，后续水驱的初始阶段成为主要的增油阶段，驱替结束可最终提高采收率达28.92%。图8参16

The changes of pressure and saturation, the production characteristics and distribution of remaining oil about low tension foam system under simulated reservoir condition of Shengli oilfield were studied by sand-pack and consolidated physical models. The results showed that the low tension foam flooding could increase the injection pressure of whole model, and improve the formation heterogeneity through profile control and fluid division. It was found that as the gas floating effect could be ignored in the early stage of foam injection, due to the viscous and capillary force, the low tension foam was mainly in the middle and lower parts of the model and the pressure in middle and lower parts was relatively a little higher. But at the later stage, foam distributed evenly in the model and could be displaced like a piston under the comprehensive effect of gas floating and viscous forces. As a result, the pressure changed more gently. Remaining oil mainly gathered in the outlet of the model, and the displacement efficiency near the inlet of the model was the best. Under the charge of the displacement of low tension foam, and in combination with gas buoyancy and oil washing effects, oil was mainly recovered at the initial stage of subsequent water flooding, and finally the integrated oil recovery was increased by 28.92%. Furthermore, the displacement efficiency in high and low permeability layers was much better.