Organo-Clay Complexes in Source Rocks——A Natural Material for Hydrocarbon Generation
详细信息
- 责任者：Cai Jingong (The State Key Laboratory of Marine Geology ; Tongji University ; Shanghai 200092 ; China) ; Song Mingshui
- 刊名：Marine Geology & Quaternary Geology
- 出版年：2013
- 卷期：33(3)
- 关键词：烃源岩 ; source rocks
- 页码：p.123-131
- 图表：illus., 2 tables, 32 refs.
- 分类号：1003
- issnNo：ISSN0256-1492
- isbnNo：CN37-1117/P
摘要
Traditionally,it is believed that kerogen,a organic matter insoluble in organic solvents separated chemically from source rock,is a material for hydrocarbon generation[1].The procedure to treat samples as such,however,may destroy the original occurrence and relationship between organic matter and clay in source rocks.We extracted an organo-clay complex(<2μm) from the crushed source rocks in the depth of 280~3 500 m,in the Jiyang sag,East China.The complex is mainly composed of layered illite-smectite(I-S) and illite with a value of TOC up to 2.62%~9.78%.After treatment with H2 O2,TOC remains as high as 1.23%~4.63%,suggesting that it is the components in which organic matters are enriched.The diffraction peak(d001) of the complex is 1.3~1.4nm at 250℃,and moves to 1.0 nm at 550 ℃ in XRD curves,and the exothermic peaks of the complex is extraordinary stable at 350 ℃ in DTA curves.;The result is consistent in both the XRD and DTA observations.It indicates that organic matter can enter the interlayer space of clay minerals.With PY-GC analysis,the organic matter of C5 and C25 is released from the complex in a temperature range of 250~650 ℃,and reaches a peak at about 450 ℃.Our findings reveal that organic matter can enter interlayer of clay minerals forming a kind of natural and highly stable organo-clay complex,and the composition of the organic matter in the complex is similar to the crude oil.As a kind of natural material,the organo-clay complex plays an important role in hydrocarbon generation in source rocks.