中国石油大学学报（自然科学版）2025，Vol.49Issue(3)：28-36,9.DOI:10.3969/j.issn.1673-5005.2025.03.004
纳米流体作用下特低渗储层孔隙水赋存特征
Occurrence characteristics of pore water in ultra-low permeability reservoirs influenced by nanofluids
摘要
Abstract
Nano-fluids has significant advantages in reducing water injection pressure and improving injection capacity in ul-tra-low permeability reservoirs.In this study,the influence of drag reducing nano-fluids by adsorption on fluid flow and mi-gration characteristics in porous media was experimentally investigated.The evolution behavior of movable fluid saturation and the occurrence characteristics of water phase in pores were analyzed,and the microscopic flow characteristics were re-vealed.The experimental results show that,compared with the original untreated ultra-low permeability core,0.05%mass fraction of the nanofluid can increase the movable fluid saturation by 7.7%in rock samples.The movable water and adsorbed water were assessed by a high temperature drying method.It was found that nanoparticles adsorbed on the pore throat wall can change the movable water distribution in pore size larger than 40 nm,and reduce the equivalent bound water film thick-ness by 2.25-10.25 nm.Micro channel visualization experiments combined with high-speed camera analysis show that the nano-fluid adsorption on pore walls can change the distribution characteristics of the flow field significantly.The maximum flow velocity in the center of the pore can be increased from 0.022 m·s-1 to 0.027 m·s-1,which demonstrates that the nano fluid can effectively reduce flow resistance and increase injection capacity by reducing the drag force from pore walls.The results reveal the mechanisms of resistance reduction and injection increase of ultra-low permeability reservoirs enhanced by nanofluids in terms of pore water mobility,bound water film thickness and microchannel velocity,which can provide a theoretical basis for an efficient development of ultra-low permeability reservoirs.关键词
赋存特征/孔隙水/纳米流体/降压/特低渗储层Key words
occurrence characteristics/pore water/nanofluids/depressurization/ultra-low permeability reservoir分类
石油、天然气工程引用本文复制引用
孙永鹏,由庆,徐曼露,张海涛,刘文博,戴彩丽,王秀伟,赵文勋,曾思哲,辛岩..纳米流体作用下特低渗储层孔隙水赋存特征[J].中国石油大学学报（自然科学版）,2025,49(3):28-36,9.基金项目
国家重点研发计划项目(2019YFA0708700) （2019YFA0708700）
