柴达木盆地北缘东段石炭系生烃潜力及其地质意义  

Hydrocarbon Generating Potential of Carboniferous Source Rocks in East Part of North Margin of Qaidam Basin and Their Geological Significance

作　　者：张明峰[1] 妥进才[1] 张小军 邱军利[1] 吴陈君[1] 郭力军 嵇文涛 

机构地区：[1]中国科学院地质与地球物理研究所,油气资源研究重点实验室,甘肃兰州730000 [2]中国石油西北地质研究所,甘肃兰州730020 [3]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [4]中国石油长庆油田分公司技术监测中心,陕西西安710018

出　　处：《现代地质》2012年第4期723-731,共9页Geoscience

基　　金：中国科学院重要方向项目(KZCX2-EW-104);中国科学院西部之光人才培养西部博士项目(Y134MF1ZMF);国家自然科学基金项目(41103022)

摘　　要：依据烃源岩有机质丰度、有机质类型、有机质成熟度和可溶有机质特征分析,发现柴达木盆地北缘东段上石炭统泥质烃源岩有机碳含量平均为1.26%,有机质类型主要以Ⅲ型和Ⅱ型为主;碳酸盐岩有机质丰度较低,平均为0.24%,有机质类型较好,为Ⅱ和Ⅰ型;有机质正处于成熟阶段后期-高成熟早期,有的还处在大量生烃阶段,表明上石炭统烃源岩达到中等—好生油岩级别。石炭系烃源岩有机质形成于较强还原条件下的咸水环境,具有丰富的低等水生生物和藻类母质输入。运用地球化学指标和柴达木盆地北缘各构造带原油系统对比研究,表明石炭系烃源岩对冷湖、南八仙构造带原油没有实质性的贡献。马北构造带个别原油样品中表现出存在来源于石炭系烃源岩的油源,揭示柴达木盆地北缘东段石炭系烃源岩是不可忽视的又一套烃源岩。According to the basic geochemical data of organic abundance,organic type,organic maturity and biomarker,the organic geochemical characters of the Carboniferous source rocks in east part of north margin of Qaidam Basin are analyzed.Results are as follows：（1）The dark-colored mudstone has an average organic carbon content of 1.26% and the organic matter is mainly of Ⅲ and Ⅱ types;（2）The carbonate rocks has a low organic carbon content with an average of 0.24%,and the organic matter is of ⅡandⅠtypes;（3）Hydrocarbon source rocks with a moderate-high organic matter maturity,have larger hydrocarbon-generating potential.The dark-colored mudstone and carbonate rocks both reach the standards of good to moderate hydrocarbon source rock.The sedimentary organic matters are dominantly derived from lower hydrobiont and algae,and deposit in a strong reducing environment of saline water.The comparison study of discovered crude oils of north margin of Qaidam Basin indicates that the crude oils in Lenghu area and Nanbaxian oilfield have little contribution from Carboniferous source rocks.In Mabei oilfield,some crude oil samples are from the Carboniferous source rocks,indicating new petroleum exploration area in north margin of Qaidam Basin.

关 键 词：柴达木盆地北缘东段 石炭系 烃源岩 油气地球化学 油源对比 

分 类 号：TE122.1[石油与天然气工程—油气勘探]