致密砂岩储层微观孔隙结构特征及其对油水渗流的影响  

Microscopic Pore Structure of Tight Sandstone Reservoirs and Its Influence on Oil-Water Seepage

作　　者：郑超 祁笑寒 赵爱芳 曹石年 郭海滨 王进 徐文斯 ZHENG Chao;QI Xiaohan;ZHAO Aifang;CAO Shinian;GUO Haibin;WANG Jin;XU Wensi(Laojunmiao Oil Production Plant,PetroChina Yumen Oilfield Company,Jiuquan,Gansu 735000,China)

机构地区：[1]中国石油玉门油田公司老君庙采油厂,甘肃酒泉735000

出　　处：《西安石油大学学报(自然科学版)》2025年第2期65-73,84,共10页Journal of Xi’an Shiyou University(Natural Science Edition)

基　　金：国家科技重大专项“鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程”(2016ZX05050)。

摘　　要：为明确致密砂岩孔隙结构对水驱油渗流机理的影响,采用场发射扫描电镜、铸体薄片和高压压汞实验等多种技术,对延长组长7致密砂岩储层微观孔隙结构进行了综合表征,研究了微观孔隙结构对油水渗流参数的影响,分析了致密砂岩微观孔隙的水驱动用规律。研究表明,当渗透率小于0.1×10^(-3)μm^(2)时,纳米孔(<0.1μm)对渗透率的贡献率达到70%以上。当渗透率大于0.3×10^(-3)μm^(2)时,亚微孔(0.1~1.0μm)对渗透率的贡献率达到70%以上。亚微孔和微孔(>1.0μm)的初始含油饱和度与渗透率呈正相关性,而纳米孔初始含油饱和度与渗透率呈负相关性。亚微孔驱油效率(平均值为62.40%)远高于纳米孔和微孔,且随着渗透率的增加,纳米孔驱油效率降低,亚微孔和微孔驱油效率增大。To clarify the influence of the pore structure of tight sandstone on the seepage mechanism of water driving oil,the micro pore structure of Yanchang Formation Chang 7 tight sandstone reservoir were comprehensively characterized by means of various techniques such as field emission scanning electron microscopy,casting thin sections,and high-pressure mercury injection experiments.The influence of micro pore structure on oil-water seepage parameters was studied,and the water driving oil behavior in micro pores of tight sandstone was analyzed.The results show that when the permeability of tight sandstone is less than 0.1×10^(-3)μm^(2),the contribution rate of the nanopores(<0.1μm)to the permeability can reach more than 70%.When the permeability is greater than 0.3×10^(-3)μm^(2),the contribution rate of sub-micropores(0.1~1.0μm)to the permeability reaches over 70%.The initial oil saturation of sub-micropores and micropores(>1.0μm)is positively correlated with permeability,while the initial oil saturation of nanopores is negatively correlated with permeability.The oil displacement efficiency of sub-micropores(average 62.40%)is much higher than that of nanopore and micropores,and with the increase of permeability,the oil displacement efficiency of nanopore decreases,and the oil displacement efficiency of sub-micropores and micropores increases.

关 键 词：油水渗流 孔隙结构 孔隙半径 核磁共振 致密砂岩 

分 类 号：TE349[石油与天然气工程—油气田开发工程]