泌阳凹陷深凹区页岩非均质性与含油性特征分析

Heterogeneity and oil-bearing property of shale in Biyang Depression and their influencing factors

吕倩 李水福 胡守志 黄新

（中国地质大学（武汉）资源学院，湖北 武汉 430074）

 (Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China)

页岩的非均质性和含油性研究，对揭示页岩油微观富集规律和页岩油开发都具有重要意义。运用地球化学、核磁共振、岩心观察、X衍射等方法，对南襄盆地泌阳凹陷页岩岩性、矿物组成、有机质丰度、孔渗性和含油性等特征进行了研究。结果表明：泌页1井5号页岩层有机质丰度呈中部高、顶底低的分布特点；中部和底部页岩段的含油量比顶部高；顶部页岩段粉砂质质量分数较高，中部页岩段灰质质量分数较高，底部页岩段云质质量分数较高；页岩中陆源碎屑矿物质量分数随深度增加而增多，黏土矿物质量分数则相反，碳酸盐矿物质量分数呈中部高、顶底低的趋势；页岩渗透率随深度增加而增大，而孔隙度变化不大；页岩层形成于干旱气候下具有中—高等生产力的咸水还原环境中；有机质丰度、脆性矿物质量分数、孔隙度和烃类微运移作用是影响页岩含油量的主要因素；与高有机质丰度页岩层段相邻的泥质粉砂岩和云质页岩夹层是页岩油开采的有利层段。

 Researches on heterogeneity and oil-bearing property of shale play an important role in shale oil development and revealing microscopic hydrocarbon accumulation mechanism. Based on geochemical analysis, nuclear magnetic resonance (NMR), core observation, X-ray diffraction and other methods, conclusions were summarized as follows: organic matter abundance is high in the middle and low in the top of the fifth shale of Biye 1 well; oil content is higher in the middle and bottom of the fifth shale than the top; lithofacies features mainly include high silty content in the top, high calcareous content in the middle, and high dolomitic content in the bottom of shale; as contrasted with terrigenous detrital mineral content which increases with increasing burial depth, the variation tendency of clay mineral content is adverse and carbonate mineral content is high in the middle of shale; permeability increases and porosity has little change in the fifth shale with increasing burial depth; the fifth shale is formed in an anaerobic saline sedimentary environment with medium-high productivity in a dry paleoclimate and the depositional period of the middle part of the fifth shale is the most conducive to the preservation of organic matter; organic matter abundance, brittle mineral content, porosity and intra-source migration are the key factors of shale oil content; muddy siltstone and dolomitic shale adjacent to high organic matter abundance of shale are favorable for shale oil exploitation.

10.6056/dkyqt201603003