下扬子地区二叠系页岩有机质孔隙发育特征及其影响因素

发布时间：2018-05-14 02:26

本文选题：下扬子地区 + 二叠纪　；参考：《天然气工业》2017年10期

【摘要】：利用高分辨率成像技术实现不同类型页岩孔隙结构的定性描述和定量表征是页岩储层评价研究的重要课题之一。为此,选取下扬子地区二叠系大隆组和孤峰组2套页岩作为研究对象,首先采用氩离子抛光—扫描电镜技术对其有机质孔隙结构进行了系统的观察,再结合三维重构数据和Image J软件对有机质孔隙结构参数进行了统计与分析,最后探讨了影响有机质孔隙发育的主要因素。结果表明:(1)该区页岩有机质孔隙可划分为有机质粒内孔、有机质边缘收缩缝、有机质内部微裂隙3种类型,不同的有机质其孔径、孔隙数量、面孔率、有机质孔隙度等孔隙结构参数存在着较大的差异;(2)不同的有机质孔隙类型是随着有机质热演化作用推进阶段的不同而形成的,伴随着有机质生烃演化过程的进行,有机质粒内孔持续发育,并逐渐形成有机质边缘收缩缝,高演化条件下在有机质局部(特别是镜质体组分)还会产生有机质内部微裂隙;(3)该区页岩有机质孔隙发育非均质性的内因主要受控于有机碳含量、有机质热演化程度、有机质显微组分以及黏土矿物含量等因素,而外因则主要受控于异常压力。
[Abstract]:The qualitative description and quantitative characterization of different types of shale pore structures using high resolution imaging technology is one of the important topics in shale reservoir evaluation. Therefore, two sets of shale from Dalong formation and Gufeng formation of Permian system in Lower Yangtze region were selected as research objects. Firstly, the pore structure of organic matter was systematically observed by argon ion polishing and scanning electron microscopy. Combined with 3D reconstruction data and Image J software, the pore structure parameters of organic matter were statistically analyzed, and the main factors affecting the pore development of organic matter were discussed. The results show that the pores of shale organic matter in this area can be divided into three types: organic matter inner pore, organic matter edge shrinking joint, organic matter internal microcrack, different organic matter pore size, pore number and porosity. The porosity of organic matter and other pore structure parameters are different. (2) the different pore types of organic matter are formed with different stages of thermal evolution of organic matter, which is accompanied by the evolution process of hydrocarbon generation of organic matter. Organic matter intragranular pores continued to develop and gradually formed marginal shrinkage joints of organic matter. Under high evolution conditions, organic matter (especially vitrinite components) will also produce microcracks in organic matter. The internal causes of the porosity heterogeneity of shale organic matter in this area are mainly controlled by organic carbon content and the degree of thermal evolution of organic matter. The macerals of organic matter and clay mineral content are mainly controlled by abnormal pressure.
【作者单位】：非常规油气湖北省协同创新中心;长江大学油气资源与勘察技术教育部重点实验室;中海石油(中国)有限公司上海分公司;中国石油西南油气田公司川西北气矿;
【基金】：国家自然科学基金项目“中扬子区下古生界页岩气关键评价指标限定值研究”(编号:41402114)
【分类号】：P534.46;P618.13

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