鄂尔多斯盆地三叠系延长组长7段陆相页岩层系致密储层充注物性下限及其控制因素  

Lower Limit of Physical Properties of Filling Materials in Tight Reservoirs of the Chang 7 Member,Triassic Yanchang Formation,Ordos Basin,and Their Controlling Factors

作　　者：李辉[1] 张涛[1] 侯雨庭 喻健 何鑫 陈世加[2,3,4] 李勇 LI Hui;ZHANG Tao;HOU Yuting;YU Jian;HE Xin;CHEN Shijia;LI Yong(Exploration Division of PetroChina Changqing oil field Branch,Xi’an,Shaanxi 710018,China;School of Earth Science and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China;State Key Laboratory of Oil and Gas Reservoir Geology and Development Engineering,Chengdu,Sichuan 610500,China;Sichuan Key Laboratory of Natural Gas Geology,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石油长庆油田分公司勘探事业部,陕西西安710018 [2]西南石油大学地球科学与技术学院,四川成都610500 [3]油气藏地质及开发工程国家重点实验室,四川成都610500 [4]天然气地质四川省重点实验室,四川成都610500

出　　处：《现代地质》2024年第6期1498-1510,共13页Geoscience

基　　金：国家自然科学基金项目(42072185,41872165);CNPC-SWPU创新联合体科技合作项目(2020CX030000,2020CX050000)。

摘　　要：近年来,鄂尔多斯盆地长7段页岩层系致密储层油藏勘探取得重大突破,其储层充注物性下限的大小是评价该地区致密油勘探开发潜力的关键。本次研究通过孔隙度、渗透率(简称为孔渗)含油饱和度分析以及高压压汞等实验方法,采用物性试油法、经验统计法和孔喉半径法分析不同地区、不同层位致密储层充注物性下限,并探讨其控制因素和对油气富集的影响。结果表明:陇东—姬塬地区致密砂岩以石英为主,储层孔渗平均为8.17%和0.15×10^(-3)μm^(2);陕北地区致密砂岩以长石为主,储层孔渗平均为8.20%和0.21×10^(-3)μm^(2)。陇东—姬塬地区的长71段致密储层孔渗下限为4.93%和0.034×10^(-3)μm^(2),长72段致密储层孔渗下限为4.36%和0.027×10^(-3)μm^(2);陕北地区长71段致密储层孔渗下限为5.90%和0.048×10^(-3)μm^(2),长72段致密储层孔渗下限为5.60%和0.043×10^(-3)μm^(2)。储层充注物性下限受储层物性、源岩生烃能力和源储间距三个因素影响。储层物性好、烃源岩生烃能力强、源储间距小的地区储层充注下限低,如烃源岩厚度更大的陇东—姬塬地区储层充注下限低于陕北地区,源储间距小的长72段储层充注下限低于长71段。储层充注物性下限越低,储层含油饱和度越高。储层充注下限低的陇东地区,平均含油饱和度为31.28%,陕北地区平均含油饱和度则为28.40%,明显低于陇东地区。同理,长72段储层含油饱和度高于长71段储层。Recently,significant breakthroughs have been achieved in exploring tight reservoirs within the Chang 7 Member of the Yanchang Formation in the Ordos Basin.The lower limit of reservoir filling material properties is crucial for assessing the potential for tight oil exploration and development in this area.In this study,we analyzed the lower limit of physical properties for filling materials in tight reservoirs across different regions and layers using pore penetration analysis,oil saturation measurement,and high-pressure mercury injection.Additionally,we examined the lower limit of physical properties for filling materials in tight reservoirs across different regions and layers using the physical oil test method,empirical statistical analysis,and pore throat radius method.We also explored the controlling factors and their influence on the oil and gas enrichment.The results indicate that in the Longdong-Jiyuan area,dense sandstone is primarily composed of quartz,with an average reservoir pore penetration of 8.17%and 0.15×10^(-3)μm^(2);in contrast,the dense sandstone in north Shaanxi is predominantly feldspar,exhibiting an averages reservoir pore penetration of 8.20%and 0.21×10^(-3)μm^(2).In the Longdong-Jiyuan area,the lower limit of physical properties for dense reservoirs in the Chang 71 submember is 4.93%and 0.034×10^(-3)μm^(2),while in the Chang 72 submember,it is 4.36%and 0.027×10^(-3)μm^(2).In north Shaaxi,the lower limit of the physical properties for dense reservoirs in the Chang 71 submember is 5.90%and 0.048×10^(-3)μm^(2),while in the Chang 72 submember,it is 5.60%and 0.043×10^(-3)μm^(2).The lower limit of reservoir filling is influenced by three factors:the physical properties of the reservoir,the hydrocarbon generation capacity of source rocks,and the distance between the sources and reservoirs.The lower limit of reservoir filling is lower in the areas with favorable reservoir properties,high hydrocarbon generation capacity of source rocks,and minimal distance between sources and reservoirs.

关 键 词：鄂尔多斯盆地 长7段 页岩层系 致密储层 充注物性下限 控制因素 原油富集 

分 类 号：P618.1[天文地球—矿床学]