不同含油饱和度时泡沫的稳定性及调驱机理研究

利用搅拌起泡法研究了含油饱和度对于泡沫稳定性的关系,利用微观玻璃模型研究了不同含油饱和度时泡沫的调驱机理,利用双管并联填砂岩心模型评价了不同含油饱和度时的调剖效果。结果表明:含油饱和度对泡沫稳定性有明显影响,含油饱和度0.05~0.2区间内,泡沫稳定性缓慢降低,含油饱和度0.2~0.4区间内,泡沫稳定性快速降低,含油饱和度0.4~0.6以上区间内泡沫稳定性缓慢降至较低水平;微观玻璃模型驱替实验表明,含油饱和度在0.4~0.6区间内泡沫不能稳定存在,泡沫依靠泡沫剂溶液的洗油作用提高采收率,0.05~0.2区间内泡沫稳定性较好,主要依靠气泡的调堵作用提高采收率,0.2~0.4区间内调堵作用和洗油作用协同;含油饱和度对于泡沫的调剖效果有显著影响,在实验条件下,含油饱和度在0.1~0.3区间内,驱替压差可达1.2 MPa,泡沫调剖作用显著,在0.3~0.6区间内,驱替压差逐渐降至0.3 MPa,调剖效果不理想,含油饱和度大于0.6,驱替压差低于0.2 MPa,泡沫失去调剖作用。

Foam Stability and Mechanism on Profile Control under Different Oil Saturation

The foam stability and oil saturation was studied with stirring method, the mechanism on profile control was studied with micro model, and the profile control effect was studied with parallel san pack. Results show that, oil saturation has an obvious influence on foam stability, in 0.05-0.2 interval, stability decreases slowly, in 0.2-0.4 interval, stability decreases sharply, finally in 0.4-0.6 interval stability reaches a stable level. The enhancement of recovery relies on surfactant system swapping in high oil saturation in oil saturation 0.4-0.6, while in low saturation 0.05-0.2 relies on water shut-off of Jamin effect. In a condition of this paper, the flood pressure can be 1.2MPa at oil saturation 0.1-0.3, profile control effect works well, and pressure decreases to 0.3MPa at oil saturation 0.3-0.6, the profile control effect is not obvious, finally when oil saturation reaches 0.6 and higher, profile control effect decreases to none.