Effect of organic matter on pore structure of mature lacustrine organic-rich shale: A case study of the Triassic Yanchang shale, Ordos Basin, China
Effect of organic matter on pore structure of mature lacustrine organic-rich shale: A case study of the Triassic Yanchang shale, Ordos Basin, China
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有机质对成熟湖相富有机质页岩孔隙结构的影响——以鄂尔多斯盆地三叠系延长页岩为例
DOI：
10.1016/j.fuel.2016.07.100
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发表时间：
2016-12-01
期刊：
影响因子：
7.4
通讯作者：
Li, Chengcheng
中科院分区：
文献类型：
--
作者：
Li, Jing;Zhou, Shixin;Li, Chengcheng
研究了鄂尔多斯盆地延长组泥质中可提取有机质和固体有机质对泥质孔隙结构的影响。页岩样品经破碎、二氯甲烷萃取去除可萃取有机质、过氧化氢处理去除固体有机质。采用低压气体吸附法、X射线衍射（XRD）法和岩石热解法对泥页岩样品的孔隙度、有机质和矿物学特征进行了分析。结果表明，可提取有机质不同程度地占据和堵塞了泥页岩的孔隙，严重影响了孔隙度。小直径的孔隙将被优先占据和堵塞。富含有机质的页岩中大量生成碳氢化合物，导致孔隙中流体压力较高，从而保护孔隙在演化过程中免受压实作用，导致孔隙度较高。这种保护作用主要作用于大孔隙。所研究的页岩孔隙以石英和粘土质孔隙为主，有机质孔隙很少。固体有机质含量是影响泥页岩总孔隙度的主要因素。首先，高含量的固体有机质降低了石英和粘土矿物的相对含量，导致总孔隙度较低。其次，固体有机质占据并堵塞了与石英和粘土矿物有关的孔隙。(C)2016爱思唯尔有限公司版权所有
The effect of extractable organic matter and solid organic matter on the pore structure of shale from Yangchang Formation in the Ordos Basin, China is investigated in this study. The shale samples were successively crushed, extracted by dichloromethane to remove extractable organic matter, treated by hydrogen peroxide to remove solid organic matter. The porosity, organic and mineralogical characteristic of original, extracted and H2O2 treated shale samples were analyzed via low pressure gas adsorption measurement, X-ray diffraction (XRD) and Rock-Eval pyrolysis. Results show that pores in the studied shale were occupied and blocked by extractable organic matter with varying degrees which seriously affect porosity. Pores with small diameter will be preferential occupied and blocked. The plentiful generation of hydrocarbon in organic-rich shale will lead to high fluid pressure in pore which protect pore from compaction during evolution and lead to a higher porosity. This protection mainly act on macropores. Pores in the studied shale were dominated by quartz-related and clay-related pores, and organic matter hosted pore is rare. Solid organic matter content act as a harmful factor to total porosity of studied shale. Firstly, high content of solid organic matter reduce the relative content of quartz and clay minerals then lead to a low total porosity. Secondly, solid organic matter occupied and blocked pores related to quartz and clay minerals. (C) 2016 Elsevier Ltd. All rights reserved.