基于致密砂岩储层孔隙结构全孔径表征的压裂液渗吸效率影响因素OA

Tight sandstone reservoir exhibits characteristics such as complex pore structure,high heterogeneity and obscure flow pattern,making it prone to have water-blocking effect with fracturing fluid during fracturing produc-tion,thereby impacting oil recovery.In order to clarify the influencing factors of fracturing fluid imbibition in tight sandstone reservoir,research on full pore structure characteristics is conducted on core samples from the 8th mem-ber of Shihezi Formation(He8 Member)in Yichuan-Huanglong area of Ordos Basin based on experiments such as nuclear magnetic resonance,high-pressure mercury injection and gas adsorption.Imbibition experiments are per-formed to determine the main controlling factors of imbibition efficiency.The results show that tight sandstone reser-voirs in studied area are dominated by micropores,with relatively good connectivity and high pore-structure hetero-geneity,impacting the reservoir flow capacity.Imbibition efficiency of tight sandstone reservoirs is influenced by fac-tors such as physical properties,pore size,connectivity and wettability,with the correlation to imbibition efficiency ranking as:pore size＞permeability＞connectivity＞wettability＞porosity.Among them,micropores exhibit the highest correlation with imbibition efficiency,indicating that they are the main influencing factors of imbibition.The re-search provides significant guidance for improving fracturing technology and enhancing oil recovery of tight sand-stone reservoirs.