细粒混积岩储层特征与主控因素分析——以渤海湾盆地沧东凹陷孔二段为例  

Characteristics and controlling factors of fine-grained mixed sedimentary rocks reservoir: A case study of the 2nd member of Kongdian formation in Cangdong depression, Bohai Bay basin

作　　者：邓远 蒲秀刚[2] 陈世悦[1] 鄢继华[1] 时战楠 张伟[2] 韩文中[2] DENG Yuan;PU Xiugang;CHEN Shiyue;YAN Jihua;SHI Zhannan;ZHANG Wei;HAN Wenzhong(School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Research Institute of Exploration and Development,PetroChina Dagang Oilfield Company,Tianjin 300280,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石油大港油田分公司勘探开发研究院,天津300280

出　　处：《中国矿业大学学报》2019年第6期1301-1316,共16页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(41572087)

摘　　要：为深化对细粒混积岩储层发育特征与控制因素的认识,以渤海湾盆地沧东凹陷孔店组二段为例,利用岩心观察、薄片鉴定、X射线衍射、场发射扫描电镜、低温气体吸附、纳米CT与聚焦离子束-场发射扫描电镜等方法,在总结细粒混合沉积样式的基础上,对比分析不同混积样式储集空间类型、孔隙结构特征、储集空间展布与连通性的差异,认为组分型细粒混积岩的总孔隙体积、总比表面积和平均孔径均大于组构型细粒混积岩,储集空间的连通性也好,储层的发育和演化受沉积环境、成岩作用和有机质热演化的共同控制.研究结果表明:孔店组二段细粒混积岩可分为组分混合与组构混合两类,主要的储集空间包括宏观裂缝和微观孔隙,其中裂缝分为构造缝、层理缝、成岩收缩缝和异常高压缝等4类,孔隙分为无机质孔隙、有机质孔隙和微裂缝3类;组分型细粒混积岩的总孔隙体积平均为0.013 cm^3/g,总比表面积平均为9.058 m^2/g,平均孔径为4.05 nm,易于形成良好的立体孔缝网络;组构型细粒混积岩的总孔隙体积平均为0.004 cm^3/g,总比表面积平均为3.611 m^2/g,平均孔径为3.75 nm,储集空间连通性较差;沉积环境决定了岩石的物质组成与混积样式,提供储集空间发育的物质基础;成岩作用控制储集空间的类型与特征;有机质热演化与无机成岩作用相互协同,影响储集空间的形成与演化.To deepen the understanding of characteristics and controlling factors of fine-grained mixed sedimentary rocks, taking the 2nd member of Kongdian formation in Cangdong depression of Bohai Bay basin as an example. Based on the detailed description of core, thin section identification, X-ray diffraction analysis, field emission scanning electron microscopy, low-temperature N2 and CO2 adsorption experiments, nano-CT and focused ion beam scanning electron microscope, the mixture patterns of lacustrine fine-grained mixed sedimentary rocks were summarized. And the reservoir space types, pore structures, reservoir space spatial distribution and connectivity of each mixture patterns were analyzed. It is indicated that the pore volume, specific surface area, pore size, reservoir space spatial distribution and connectivity of componential mixture samples are greater than those of structural mixture samples. The formation and evolution of reservoirs were controlled by the sedimentary environment, diagenesis and organic matter thermal evolution. The results show that fine-grained mixed sedimentary rocks in the 2nd member of Kongdian formation in Cangdong depression were divided into componential mixture(CM) and structural mixture(SM). The reservoir space can be divided into two types, including macroscopic fractures and microscopic pores. The fractures include structural fracture, bedding fracture, diagenetic contraction fracture and abnormal pressure fracture. The microscopic pores consist of inorganic pores, organic pores and microfractures. The average pore volume, specific surface area and pore size of CM samples are 0.013 cm^3/g, 9.058 m^2/g and 4.05 nm, respectively. The pores and fractures in CM samples can easily form a three-dimensional network. The average pore volume, specific surface area and pore size of SM samples are 0.004 cm^3/g, 3.611 m^2/g and 3.75 nm, respectively. The pores are mostly isolated and their connectivity is inferior to that of CM samples. The sedimentary environment determines the composition

关 键 词：细粒混积岩 混合沉积 储集空间 孔隙结构 孔店组二段 沧东凹陷 

分 类 号：TE122[石油与天然气工程—油气勘探]