中国中西部盆地典型陆相页岩纹层结构与储层品质评价  

Laminar structure of typical continental shales and reservoir quality evaluation in central-western basins in China

作　　者：吴松涛[1,2,3] 朱如凯 罗忠[1,2,3] 杨智 姜晓华[1,2,3] 林敏捷 苏玲[1,2,3] Wu Songtao;Zhu Rukai;Luo Zhong;Yang Zhi;Jiang Xiaohua;Lin Minjie;Su Ling(PetroChina Research Institute of Petroleum Exploration&Development;National Energy Tight Oil and Gas R&D Center;CNPC Key Laboratory of Oil and Gas Reservoirs)

机构地区：[1]中国石油勘探开发研究院,北京市100083 [2]国家能源致密油气研发中心 [3]中国石油天然气集团有限公司油气储层重点实验室

出　　处：《中国石油勘探》2022年第5期62-72,共11页China Petroleum Exploration

基　　金：国家自然科学基金重大项目“陆相页岩油富集主控因素与有利区带评价方法”(42090025);中国石油国际科技合作项目“陆相页岩油微纳米孔喉系统流动模拟研究”(2021DQ-0405)。

摘　　要：陆相页岩油已成为中国油气勘探重大接替领域之一。作为页岩独具特色的组构特征,纹层结构对烃源岩品质、储层品质与工程品质评价具有重要影响,因而成为关注重点。文章以中国中西部典型咸化湖盆与淡水—微咸水湖盆富有机质页岩为研究对象,剖析纹层结构特征,探讨其对甜点优选的影响。研究发现:(1)不同类型湖盆页岩纹层结构具有差异,湖盆咸化程度影响纹层结构,碳酸盐纹层主要发育在咸化湖盆,在淡水—微咸水湖盆中发育较少;(2)纹层结构具有亚毫米级非均质性特征,不同纹层的TOC与孔隙结构存在差异,同一类纹层在不同盆地的品质具有明显差异;(3)纹层结构决定了页岩油微观运聚特征与“原生源储”富集模式,影响滞留烃含量、流体可动性及压裂改造。开展陆相页岩纹层结构精细评价,寻找规模优质页岩岩相分布区,是油气勘探从源外进入源内后必须关注的问题,是源内经济有效资源发现的基础,对页岩油“甜点区”与“甜点段”优选具有重要意义。Continental shale oil has grown to be one of the major replacement fields for petroleum exploration in China. The laminar structure,a unique fabric feature of shale, significantly influences the evaluation of source rock quality, reservoir quality and engineering quality, which has attracted increasing attention for study. By taking typical organic-rich shales in saline and fresh-brackish lake basins in the central-western China as study objects, the characteristics of laminar structure are analyzed and their influence on the selection of sweet spot is discussed. The results show that:(1) The laminar structure varies in different types of lake basins, which is affected by the salinity of lake basin. The carbonate laminar is mainly developed in saline lake basin, but less in fresh-brackish lake basin;(2) The laminar structure has strong heterogeneity of sub-millimeter level. There are differences in TOC and pore structure among different laminae, and the quality of the same type of laminae varies greatly in various basins;(3) The laminar structure determines the characteristics of microscopic shale oil migration and accumulation as well as the enrichment mode of “in-situ source rock and reservoir”, and affects the retained hydrocarbon content, fluid mobility and fracturing engineering. The fine evaluation of laminar structure of continental shale and identification of the favorable lithofacies zone for high-quality shale development are the critical issues for petroleum exploration from outside to inside the source rock, which are the basis for the discovery of economic and effective resources inside the source rock and have great significance for the selection of shale oil “sweet spot area” and “sweet spot interval”.

关 键 词：非常规油气 非均质性 微纳米孔喉系统 富有机质页岩 细粒沉积 

分 类 号：TE112.221[石油与天然气工程—油气勘探]