正构烷烃分布模式判断柴西主力烃源岩.pdf

第33卷第2期
石油跨地质
201年4月
PETROLEUM GEOLOGY EXPERIMENT
文章编号:1001-6112(2011)02…182
正构烷烃分布模式判断柴西主力烃源岩
宋振响,周世新2,穆亚蓬,陈昭
(1.中国石油化工股份有限公可石油勘探开发究院无諹石油地质硏究所,江苏无锡214-51;
2.中国科学院地质与地球物理研究所气体地球化学重点实验室,兰州730000
河南省有色金属地质矿产局第二地质大队,郑州450016)
摘要:柴西原油正构煷烃分布多呈偶奇优勢(CPI<“1〉,阿烃源岩样品则多?奇供优勢分布,共有少数呈偶奇优势分布。从正构
烷烃分布模式出发,结合单体烃碳同位素分析,对樂西原油和烃源岩进行对比,以确定柴西原油形成的主力烃源岩。岍究表明
柴西深层宇力烃源层为E?次要烃源层为Fいz和!;浅层主力烃源层为N.次要烃源层为N2、从生於性能角度看,正烷烃分
布呈偶奇优势的经源岩样品,其有机碳、氮仿沥青“A”,总烃含量、转化系数等都比昱奇偶优勢分布的样品高,生烃性能较好,应为
柴西主力烃源
关鍵词:偶奇优势:单体烃碳同位素;正构烷烃燈;烃岩;第二系;柴达木金地酉部
中图分类号:TF.12.1+13
文軾标识码:A
Identification of chief hydrocarbon source rocks based on
n-alkane distribution patterns in western Qaidam Basin
Song Zhenxiang, Zh
u Iap
(1. Wuzi Research Jnstitute w Petroleam Geology, SINOPEC, Wuzi, iangsu 214151, China; 2. Key Laboratory
Gas Gen hemistry, Inst tute of Geology andl (e ph ysics, Chinese Acdemy of Scieces, Lanh, Gansa 73000, Ch n
3. No. 2(! Party. Henan Bureau of(logica ury or Nonferous Metls, Zhenghou, Ha 150016 na
Abstract. The x-alkane distribution of crude oils [rom the western Qaidam Basin is characterized b
even to-odd (C: -C2)predominance. Source rocks from the region Are mainly characterizcd by odd-to
even predominance. Based on n-alkanc distribution pattern, combined with single molecu.e carbon iso
tope analysis,, comparing crude oil with source rock, it was discussed in this paper the main source rocks
in the western Qaidam Basin. The correlation of n-alkane distribution and single molecule carbon isotope
nalysis illustrated that the chief hydrocarbon source layer was E; and the secondary layers were Ei+
and E: in deep region. Meanwhile, the chicf hydrocarbon source layer was Nt and the sccondary laycr
was N in shallow region. I]ydrocarbon potential analysis showcd that those samples with even to- odd
Cs (R) predominance possessed higher TOC, bilumen"A", Lotal hydrocarbon content and conver
sion ratio, displaying huge hydrocarbon generating potcntial
Key words everi-to-odd predo inance; single molecule carbon isotope; n-alkanes hydrocarbon source
rocks; Tertiary; western Qaidam Basin
柴达木盆地存在3个含油气系统い:柴北缘已得到共识,但到目前为止,不同学者对柴西主力
侏罗系、柴西第三系和三湖地区第四系生物气系烃源层的判別仍存在较大争议「5。目前的主
统,其中,发育有成水湖相沉积的柴西第三系集中流規点认为,该区主力烃源层系是F3和N1
了全盆地80%~90%的油气储量和产量,一直是笔者対柴西第三系烃源岩进行了系统采样及分析,
柴达木盆地的重点勘探区域。经历了50多年的重点开展了烃源岩的正构烷烃分布模式及单体烃
勘探肪程,柴西第三系烃源岩地化特征(有机碳含碳同位素特征研究?并对不同正构烷烃分布模式烃
量低,转化率高)及沉积环境(还原性强,盐度高)等源岩的生烃性能进行了对比,确定了柴西主力烃源
收稿日期:2010一C4-26:修订日期:201-(2-09
作者简介:宋振响(1983一)、男、硕士,主要从事油气地球化学供究。E-mail:$zhx0f(:6e163.com
基金项目:闲家自然科学基金项目(40572288)和中国科学院知识创新工程重要方向项目(K2ZCX2YWQ05~0305)