摘要
针对鄂尔多斯盆地华庆地区三叠系延长组长6段致密油储层,应用恒速压汞和微、纳米CT扫描分析等技术手段和方法,开展了微观孔喉结构特征研究。研究结果表明,长6致密油储层孔隙以微米级孔隙为主,纳米级孔隙分布频率较低,主流喉道半径为1.07μm,平均喉道半径为0.84μm;平均孔隙半径为140.12μm,平均孔喉比为281.03,微-纳米孔喉特征明显。喉道半径、孔喉比与孔渗关系表明,孔喉特征是影响和制约储层物性的关键因素,孔喉特征参数对渗透率的影响和制约要明显高于其对孔隙度的影响,致密油储层微-纳米CT实验表明,致密油储层发育孔喉网络复杂的纳米-微米级孔喉系统,且具连通性;微-纳米孔隙结构三维重构显示,纳米孔隙一般呈椭圆形、长条形和不规则形,微米级孔隙呈现圆形、椭圆形、三角形和不规则形,石油赋存在较大孔隙的团块状、球形斑点状孔隙结构和微裂缝中。
Structural characteristics of microscopic pore-throats of the Chang6Member tight oil layer of the Triassic Yanchang Formation in the Huaqing Region,Ordos Basin were studied using techniques including constant-speed pumping and microand nano-CT scanning.Results show that the pore spaces in the Chang6Member were predominantly microscopic,while nanoscopic pore spaces were less dominant.The mainstream throat radius was1.07_m,average throat radius was0.84_m,and pore radius was140.12_m.The average pore-to-throat ratio was281.03,representing significant micro/nanoscopic porethroat characteristics.The relationships of pore infiltration with throat radius and pore-to-throat ratio show that pore-throat characteristics are the key factors that influence the physical properties of the tight oil layer.The effects and limitations of porethroat parameters on infiltration rate are more significant than those of porosity.Micro/nano-CT scans on tight oil layers indicate the presence of complex and interconnected micro/nanoscopic pore-throat networks.The three-dimensional reconstruction of micro/nanoscopic pore space reveals that nanoscopic pores are mainly oval,elongated,or irregular,whereas their microscopic counterparts are circular,oval,triangular,and irregular.Tight oil is located in micro-cracks and in the clustered and spherical pore-throat structures with relatively larger pore spaces.
作者
徐黎明
牛小兵
梁晓伟
陈亚娟
马继业
XU Liming;NIU Xiaobing;LIANG Xiaowei;CHEN Yajuan;MA Jiye(Research Institute of Exploration and Development, Changqing Oilfield Company, PetroChina, Xi′ an, Shaanxi 710018, China;Beijing Route Geumgok Oil Technology Development Co., Ltd., Haidian, Beijing 100083, China)
出处
《西南石油大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第4期36-46,共11页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家自然科学基金(41390451)
国家"973"项目(2014CB239003)
国家科技重大专项(2016ZX05046)
关键词
致密油储层
微观孔喉结构
长6储层
华庆地区
鄂尔多斯盆地
tight oil layer
microscopic pore-throat structure
Chang 6 Member oil layer
Huaqing Region
Ordos Basin
