纳米流体化学驱对油田提高采收率的影响研究

Effect of Nano-fluid Chemical Flooding on Oil Recovery

纳米流体优异的物理化学特异性或有益于低渗油田潜力的挖掘,进一步提高原油采收率。尽管国内外对纳米流体提高采收率方面的研究依旧处于实验室阶段,但纳米SiO_(2)在低渗油藏驱替特性已被基本证实。选用较为成熟的SiO_(2)颗粒配制纳米流体,研究不同质量分数(0.03%、0.06%、0.09%)纳米颗粒在低渗油田中的驱油特性,优选出最佳质量分数后,进一步开展了两种注入方式(1 PV水驱+0.5 PV纳米流体驱+1 PV水驱与0.5 PV纳米流体驱+1 PV水驱)的驱油实验。结果表明:0.06%的纳米流体驱油效果最佳,其原油采出率可达68.3%;当岩心含水率低于86%时,含水率和采出率呈S型驱替规律;注入方式对采收率影响不大,其中方案(a)的采出率仅比方案(b)高约0.6%。

The excellent physical and chemical specificity of nanofluids may be beneficial to tapping the potential of low-permeability reservoirs and further improving oil recovery.Although the research on nano-fluid EOR at home and abroad is still in the laboratory stage,the displacement characteristics of nano-SiO_(2) in low-permeability reservoirs have been basically confirmed.In this paper,mature SiO_(2) particles were selected to prepare nanofluids,and the oil displacement characteristics of different nanoparticle mass fractions(0.03%,0.06%,0.09%)in low-permeability reservoirs were studied.After the optimal concentration was selected,the oil displacement experiments of two injection methods(1 PV water drive+0.5 PV nanofluid drive+1 PV water drive and 0.5 PV nanofluid drive+1 PV water drive)were further carried out.The results showed that 0.06% nanofluid had the best oil displacement effect,and its crude oil recovery rate reached 68.3%;When the core water content was lower than 85%,the water content and recovery rate followed the S-type displacement law;The injection mode had little effect on the recovery factor,and the recovery factor of scheme(a)was only 0.6% higher than that of scheme(b).