乳状液在岩心中运移的影响因素研究

Factors of influencing the migration of emulsion in a rock core

为了研究乳状液在多孔介质中运移的影响因素及运移规律,了解乳状液对提高采收率的作用,利用长岩心作为模型进行驱替实验,研究了乳状液液滴粒径、液滴密度及运移速度对其运移规律的影响.结果表明,乳状液在孔喉中的宏观运移阻力是乳状液液滴对孔喉堵塞的累积结果.大液滴的乳状液在孔隙介质中运移阻力明显大于小液滴的乳状液.注入速度对乳状液在岩心中运移阻力影响较大,在粒径孔径匹配的条件下,存在一个临界注入速度,在临界速度下乳液在岩心中才能形成明显的封堵.速度太低,乳状液破乳严重,乳状液变形通过孔喉的能力强不容易封堵孔喉;速度太高,乳状液液滴被分散破碎、粒径变小不容易封堵孔喉.

In order to study the factors of influencing the migration of emulsion in a rock core and the migration law and understand the function of emulsion in EOR,the effects of the droplet diameter,concentration and migration rate of the emulsion on the migration law are studied by means of the displacement experiments of long cores.It is shown that the migration resistance of the emulsion droplet in the core pore is the cumulative result of the emulsion droplet plugging the pore.The migration resistance of large droplet in porous medium is obviously greater than that of little droplet.The injection rate of the emulsion has great effect on the migration resistance.Under the condition of the droplet diameter matching with the pore diameter,there is a critical injection rate,and the emulsion can form obvious plugging in the core only at the critical injection rate.When the injection rate is lower than the critical rate,the plugging can not be formed because of the serious demulsification,and when the injection rate is higher than the critical rate,it can also not be formed because of the emulsion droplet breaking.