纳米流体提高原油采收率研究和应用进展

Research and Application Progress of Nanofluid for Enhanced Oil Recovery

针对传统聚合物、表面活性剂等溶液在提高原油采收率过程中存在黏度保留率低、吸附损耗量大等问题,介绍了纳米流体提高原油采收率相关研究进展。总结了目前应用于提高原油采收率领域中纳米材料的合成方法和纳米流体稳定性的评价手段;综述了纳米流体提高原油采收率的六大主要机理,包括降低界面张力、改变润湿性、降低原油黏度、提高泡沫稳定性、结构分离压力和降压增注;调研了目前纳米流体提高原油采收率的油田现场应用进展,并提出了限制纳米流体矿场大规模应用的瓶颈问题,一是缺乏高效开发非常规油藏的纳米驱油体系;二是关于二维片状纳米流体的研发、提高采收率机理的研究及矿场先导试验三位一体的理论和技术研究尚不成系统,需要更深层次的探讨和研究。为解决纳米流体的实践推广应用指明方向。

In view of the limitations of traditional polymer and surfactant solutions in enhancing oil recovery,such as low viscosity re-tention and large adsorption loss,this paper examines the potential use of nanofluids for enhanced oil recovery and discusses recent re-search in this field.First,the synthesis of nanomaterials is described,and the methods used for evaluation of the stability of nanofluids in enhanced oil recovery in the field are summarized.Second,six mechanisms by which nanofluids enhance oil recovery are reviewed.These are:reducing interfacial tension,changing wettability,reducing crude viscosity,improving foam stability,structural disjoining pressure,and reducing pressure and increasing injection.Third,the use of nanofluids for enhanced oil recovery in the field is investi-gated.The“bottleneck”issues that limit the large-scale application of nanofluids in oilfields are also described.For example,there are currently no nanofluid flooding systems available for efficient development of unconventional reservoirs.Furthermore,there has been insufficient theoretical and technical discussion and research.More integrated research is required on inter-related matters such as the development of nanofluids containing two-dimensional nanosheets,determination of the mechanisms for enhanced oil recovery,and field pilot testing of the process.Finally,a direction for the practical introduction and application of nanofluids is proposed.