泡沫酸FCF-N的流动特征

应用泡沫酸进行低渗透油藏的油层酸化,是一项很有前途的酸化解堵方案。分别采用并联天然岩心模型和单管人造岩心模型进行流动实验,评价泡沫酸FCF-N的选择性酸化能力、酸化效果和返排率等流动特性,最终确定了FCF-N的流动特征,为泡沫酸在砂岩储层酸化中的应用提供了理论依据。研究结果表明：FCF-N能够优先封堵高渗层位,在地层中具有分流特性;高、低渗透岩心酸化前、后渗透率变化分别为5.6%,17.8%,对低渗透层位的酸化效果优于高渗透层位,具有选择性酸化的特征;酸化后泡沫酸返排率均在80%以上,自身返排能力强。

Flow behavior of FCF-N foamed acid

Foamed acid is used to acidize the oil layer of low permeability reservoir.At present,this acidizing technology develops rapidly and is becoming a prospective acidizing and blocking relief measure.Through the flow experiment using the natural core model and single-tube artificial core model,this paper evaluates and determines the flow behavior of FCF-N foamed acid,such as the capacity and effect of acidizing and backflow ratio,which provides the theoretical basis for the application of foamed acid in sandstone reservoir acidification.Study shows that FCF-N foamed acid can block up the high permeable layer preferentially and has diverting property in formation.The range of permeability is respectively 5.6% and 17.8% before and after the high and low permeable cores are acidized.The acidizing effect of low permeability layer is superior to that of high permeability layer with a behavior of selective acidizing.The backflow ratio of foamed acid after acidizing is over 80% on the average,which displays a strong backflow capacity.