利用古氧相和古生产力替代指标评价四川上寺剖面二叠系海相烃源岩  

Evaluation of the Permian marine hydrocarbon source rocks at Shangsi section in Sichuan Province using multi-proxies of paleoproductivity and paleoredox

作　　者：陈慧[1] 解习农[1,2] 李红敬[1] 苏明[2] 彭伟[2] 胡超涌[3] 

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [2]中国地质大学(武汉)资源学院,湖北武汉430074 [3]中国地质大学(武汉)生物地质与环境地质教育部重点实验室,湖北武汉430074

出　　处：《古地理学报》2010年第3期324-333,共10页Journal of Palaeogeography：Chinese Edition

基　　金：中国石油化工股份有限公司海相油气勘探前瞻性项目"海相优质烃源岩形成的地球生物学过程"(编号:G0800-06-ZS-319);地质过程与矿产资源国家重点实验室开放课题(编号:GPMR200914);湖北省自然科学基金重点项目(编号:2008CDA095)联合资助

摘　　要：中国具备良好的海相地层油气勘探前景,如何正确识别并合理评价海相烃源岩是中国海相盆地油气勘探开发中亟待解决的关键问题。作者尝试利用多个微量元素分别作为古生产力和古氧相的综合替代指标,来进行有效烃源岩评价。研究中利用四川广元上寺剖面二叠系中Mo,U,V,Cu,Ni,Zn6个微量元素测试结果,计算得到对应两组元素过剩值:Moxs,Uxs,Vxs和Cuxs,Nixs,Znxs;对这两组元素过剩值分别进行主成分分析,得到两个系数——古生产力替代指标综合系数(简称古生产力系数)和古氧相替代指标综合系数(简称古氧相系数),用以恢复海相烃源岩的古生产力和古氧相条件;将该系数与上寺剖面残余有机碳测试结果(TOC含量)进行相关性分析,依此确定古生产力和古氧相条件的定量等级划分。最终,根据该划分标准来判断上寺剖面烃源岩的品质。利用古生产力和古氧相的综合替代指标方法可为海相烃源岩评价工作提供一些新思路。Recent hydrocarbon exploration shows an encouraging hydrocarbon prospectivity for the marine strata in China. How to correctly identify and evaluate marine source rocks is of crucial importance for hydrocarbon exploration in marine basins in China. Some trace elements regarded as multi-proxies for the restoration of paleoproductivity and paleoredox conditions could be used to develop an evaluation system for effective hydrocarbon source rocks. In this paper, we use measured Moxs（a relative excess of Molybdenum compared to titanium in post-Archean Australian shale）, Uxs, Vxs, Cuxs, Nixs, and Znxs in rock samples from the Permian of Shangsi section in Sichuan Province to obtain two integrated coefficients by analyses of two major components——the paleoproductivity and the paleoredox proxy coefficients. Then, the linear relationships between the two integrated coefficients and the residual total organic carbon（TOC content）are evaluated respectively. The results are taken as a criterion to quantitatively identify the rank of the paleoproductivity and the paleoredox conditions. Finally, the paleoproductivity and the paleoredox proxy coefficients of the Shangsi section are used to restore paleoproductivity and paleoredox conditions for marine rocks and to classify the rank of source rock quality. Thus, this study would provide some new ideas for identifying and evaluating the marine hydrocarbon source rocks.

关 键 词：海相烃源岩 古生产力 古氧相 微量元素 综合替代指标 评价体系 

分 类 号：P595[天文地球—地球化学]