南祁连盆地上三叠统泥页岩有机地球化学特征  

Organic Geochemical Features of Upper Triassic Argillutite in South Qilian Basin

作　　者：陈磊 Chen Lei(Qinghai Coal Geological Exploration Institute,Xining,Qinghai 810001)

机构地区：[1]青海煤炭地质勘查院,西宁810001

出　　处：《中国煤炭地质》2020年第11期40-45,共6页Coal Geology of China

基　　金：青海省省级财政项目(2017042007ky007、2019048043qjny005)。

摘　　要：南祁连盆地上三叠统尕勒得寺组湖相沉积页岩具有良好的生烃潜力,是近年来青海省油气勘探的主攻层位。采用野外钻井、剖面样品相结合,开展干酪根C同位素、TOC、R o等试验测试,运用沉积学、岩石学及地球化学等分析手段,对南祁连盆地阳康地区尕勒得寺组页岩地球化学特征进行综合研究。南祁连盆地晚三叠世随着西秦岭的闭合,发生了由海向陆的沉积演化过程,在低洼地带沉积了深水湖相富有机质页岩,厚度较大,平面分布稳定。尕勒得寺组页岩厚度在200~400m,属于Ⅱ1腐殖腐泥型干酪根,TOC值普遍>1.0%,受到后期热事件的影响,有机质热成熟度R o普遍>3.5%,火山快速烘烤作用加速了尕勒得寺组页岩生烃过程。The lacustrine facies shale of the upper Triassic Gardsi Formation in the South Qilian Basin possesses favorable hydrocarbon generation potential,thus the main target horizon for oil and gas exploration in the Qinghai Province recent years.Through combined field drilling and sectional sampling,using analytical means of kerogen C isotope,TOC,R o etc experimental tests carried out integrated study of geochemical features of Galedesi Formation shale in the Yangkang area,South Qilian Basin.With the closing of the western Qinling Sea,sedimentation in the area has been changed from marine facies to terrestrial facies;in low-lying area deposited deep water lacustrine facies organic matter rich shale with larger thickness and stable horizontal distribution.The shale has thickness between 200~400m,with type II 1 humic-sapropelic kerogen,TOC value generally>1.0%.Impacted by later thermal events,organic matter thermal maturity R o generally>3.5%;volcanic fast baking accelerated shale hydrocarbon generation process.

关 键 词：有机质 地球化学 尕勒得寺组 阳康地区 南祁连盆地 

分 类 号：P534.51[天文地球—古生物学与地层学]