大庆石油地质与开发2026，Vol.45Issue(5)：80-89,10.DOI:10.19597/J.ISSN.1000-3754.202510032
致密砂岩储层微观孔喉结构非均质性对水驱油渗流特征的影响
Influence of microscopic pore-throat structure heterogeneity on water-flooding flow characteristics of tight sandstone reservoirs
摘要
Abstract
To investigate the influence of microscopic pore-throat structure heterogeneity on fluid mobility and water-flooding flow characteristics in tight sandstone reservoirs,13 samples from Chang 7 Member of Yanchang Forma-tion in Dingbian area of Ordos Basin are selected.High-pressure mercury injection and nuclear magnetic resonance are used to quantitatively characterize the heterogeneity and fluid mobility at different pore-throat scales.High-tem-perature and high-pressure microscopic visualization water flooding experiment is designed and conducted to clarify flow characteristics and their controlling factors.The results indicate that pore-throat structures of tight sandstone reservoirs in studied area can be classified into 4 types(Ⅰ-Ⅳ),with corresponding heterogeneity gradually increas-ing.Oil-water flow paths progressively change from uniform and network displacement to finger-network and finger displacement,while fluid mobility and oil displacement efficiency decrease sequentially.Full pore-throat size distri-bution exhibits multi-fractal characteristics.Based on fractal inflection points,the pore-throat space can be divided into large,medium and small pore throats,with corresponding fractal dimensions decreasing sequentially.Among them,medium pore throats serve as the dominant space for movable fluids.Microscopic pore-throat structure hetero-geneity is a key factor restricting reservoir fluid mobility and oil displacement efficiency,controlling the fluid occur-rence morphology,flow pathways,and remaining oil distribution.Furthermore,an increase in clay mineral content exacerbates pore-throat structure heterogeneity,reduces reservoir physical properties and fluid mobility,leading to continuous distribution of remaining oil and a decrease in oil displacement efficiency.The research can serve as an important basis for the classification,evaluation and water injection development of tight oil reservoirs in this area.关键词
致密砂岩储层/孔喉结构非均质性/水驱油/流体可动性/驱油效率Key words
tight sandstone reservoir/pore-throat structure heterogeneity/waterflooding/fluid mobility/oil dis-placement efficiency分类
能源科技引用本文复制引用
刘金宝,惠涛..致密砂岩储层微观孔喉结构非均质性对水驱油渗流特征的影响[J].大庆石油地质与开发,2026,45(5):80-89,10.基金项目
陕西省科技发展计划项目"致密砂岩储层微观孔喉结构及薄膜流动对渗吸规律的影响"(2023-JC-YB-423). （2023-JC-YB-423）
