Geochemical Characteristics and Differences of Highly Matured Bitumen in the Sinian Dengying Formation
详细信息
- 责任者：Zhu Dongya (Laboratory of Structural and Sedimentological Reservoir Geology ; Petroleum Production and Research Institute ; SINOPEC ; Beijing 100083 ; China) ; Jin Zhijun
- 刊名：Natural Gas Geoscience
- 出版年：2013
- 卷期：24(2)
- 关键词：沥青 ; asphalt ; 贵州 ; Guizhou Province
- 页码：p.382-387
- 图表：illus., 2 tables, 19 refs.
- 分类号：1003
- issnNo：ISSN1672-1926
- isbnNo：CN62-1177/TE
摘要
There is large amount of reservoir space including dissolution pores and tectonic fractures in the dolostone from the Sinian Dengying Formation in the central Guizhou uplift,which were filled with many dolomites,quartz and black bitumen.Based on the relationship,the formation of bitumen is later than that of dolomites but earlier than quartz.In this study,two groups of bitumen were sampled in Baima and Yankong outcrops,respectively.The Baima outcrop is located in Shuangliu town of Kaiyang county,Guizhou province,and the Yankong outcrop is in Yankong town of Jinsha county,Guizhou province.Both groups of bitumen have relatively high thermal maturity,and they are cubic or spherical under scanning electronic microscope.According to carbon isotopic compositions,bitumen is expected to be from the Lower Cambrian source rocks.There are remarkable differences between the two groups.Compared with those in Yankong outcrop,bitumen in Baima outcrop has relatively lower thermal maturity,higher in N,O and S contents and H/C ratios,and lighter in carbon isotopic compositions.The average Rb values for Baima and Yankong bitumen are 4.30% and 5.17%,respectively.Homogenization temperatures of fluid inclusions and Rb values indicate that bitumen of these two groups has experimented different burial-thermal evolution processes.The different processes cause the differences in element and isotopic compositions of bitumen from different locations.Such researches would be significant for further studies on genesis and sources of natural gas in the central Guizhou uplift.