气驱起泡剂综合性能评价

Comprehensive Assessment on Foaming Agent Performance for Gas Flooding

首先对2种起泡剂的发泡性、稳定性、抗盐性、抗温性、抗油性等静态性能进行了测试评价,并优选了起泡剂的最佳使用浓度。然后,针对氮气/水交替注入和氮气/起泡剂水溶液交替注入2种方式,在岩心中对起泡剂的发泡能力及封堵性能进行了评价实验。最后,从改善驱油效率的角度对起泡剂进行了评价。综合评价结果认为,B号起泡剂溶液在岩心中的封堵能力大于A号起泡剂溶液。B号起泡剂溶液与氮气交替注入的方式在岩心产生的阻力因子呈波浪增加这一特点,可能在一定程度上能够克服气水交替过程中注入能力降低的问题,对改善油藏的注入能力是有利的。从驱油效率看,B号起泡剂比A号起泡剂提高原油采收率幅度更大,降低残余油饱和度幅度更大,更适合该油藏的气驱过程。

This paper conducted the experiment study assessment on foam stability under conditions of various concentration of foaming agents,salinity,temperatures and the amount of oil.The usable concentration of foaming agents is optimized.For two modes of water alternate gas and foaming agent solution alternate gas,experiment assessment on stability and blockage of foam in core is carried out.The results show that the mode of foaming agent solution alternate gas can produce stable foams and its relevant resistance factor is greater than that of water alternate gas in core.As a result,foaming agent solution alternate gas can block the layer of high water cut with large permeability in gas flooding process for the reservoir with high water cut and adjust water injection profile or gas injection profile and improve effect of gas flooding.The comprehensive results also show that the capability of blockage of the B foaming agent is better than that of the A foaming agent.The resistance factor produced by the B foaming agent in core appears a wavy increase,which may be useful for improving the injectivity in the process of water alternate gas to some extent.In the respect of oil displacement efficiency,the B foaming agent can increase oil recovery more and decrease the residual oil saturation more than that of the A foaming agent.Therefore,A foaming agent is more suitable for the gas flooding.