Geochemical Characteristics and Oil Source Correlation of Upper Cambrian Paleo-Reservoir in Xiushan
详细信息
- 责任者：Yang Ping (Chengdu Institute of Geology and Mineral Resources ; Ministry of Land and Resources ; Chengdu 610082 ; China) ; Xie Yuan
- 刊名：Geochimica
- 出版年：2010
- 卷期：39(4)
- 关键词：油藏地球化学 ; reservoir geochemistry ; 油—源对比 ; oil-source rock correlation ; 四川 ; Sichuan Province
- 页码：p.354-363
- 图表：6 illus., 4 tables, 27 refs.
- 分类号：1003
- issnNo：ISSN0379-1726
- isbnNo：CN44-1398/P
摘要
Upper Cambrian paleo-reservoir in Xiushan has an abundance of bitumens mainly occurred in intercrystalline pores, intercrystalline solution openings and stylolite of Gengjiadian Formation coarse crystalline dolomite. Total organic carbon contents are 3.43%～7.12%, indicating abundant bitumens. Influenced by leaching and oxidation of surface water and microbial degradation, the bitumens have low contents of chloroform bitumen “A”, pyrolysis hydrocarbon and saturated hydrocarbon, high contents of aromatic hydrocarbon and non-hydrocarbon, and low ratios of ∑C21-/∑C21+. The solid carbon isotopic compositions have a bimodal distribution pattern with the ranges from-26.7‰ to-25.6‰ and from-29.1‰ to-28.8‰, indicating at least two stages of oil-gas accumulation of the paleo-reservoir, and the hydrocarbons may come from different source rocks. Based on the analysis of the biomarkers, δ13Corg values and carbon isotopic compositions of individual n-alkanes, it is concluded that the bitumens came from the Lower Cambrian black limestone and black shale.