库车坳陷中生界强还原腐殖煤的发现及意义——海侵事件的地球化学证据  

Discovery and Significance of Mesozoic Strongly Reducing Humic Coal in Kuqa Depression—Geochemical Evidence of Transgressive Event

作　　者：谢巍 程青松 曾昌民 黄光辉 田东江 张敏 Xie Wei;Cheng Qingsong;Zeng Changmin;Huang Guanghui;Tian Dongjiang;Zhang Min(Experimental Testing Research Institute,PetroChina Tarim Oilfield Company,Korla Xinjiang 841000;Research Institute of Exploration and Development,PetroChina Zhejiang Oilfield Company,Hangzhou Zhejiang 310023;College of Resources and Environment,Yangtze University,Wuhan Hubei 430100)

机构地区：[1]中国石油塔里木油田分公司实验检测研究院,新疆库尔勒841000 [2]中国石油浙江油田分公司勘探开发研究院,浙江杭州310023 [3]长江大学资源与环境学院,湖北武汉430100

出　　处：《中外能源》2024年第11期44-54,共11页Sino-Global Energy

基　　金：国家自然科学基金项目“深层碳酸盐岩储层流体活动示踪油气差异成藏效应研究——以塔里木盆地富满油田为例”(编号42302154);“严重降解原油生物降解程度分子标志物综合评价标准研究”(编号:42272160);中国石油天然气股份有限公司风险勘探科技专项“中小盆地风险勘探领域和目标研究、技术攻关及现场试验”(编号:2023YQXCNS001-10)。

摘　　要：为了查明塔里木盆地库车坳陷中生界强还原性腐殖煤的成因,探讨其特殊的沉积环境,对晚三叠系-侏罗系的煤系烃源岩开展系统的有机岩石学和有机地球化学研究。结果表明,虽然显微组分组成表现为典型腐殖煤的特点,但其生物标志化合物的组成与正常腐殖煤明显不同。其Pr/Ph(姥鲛烷/植烷)值低,高碳数规则与不规则型类异戊二烯烷烃发育,萜类组成中具有相对较高的三环萜烷,伽马蜡烷相对丰度较高。甾烷组成中C27规则甾烷相对丰度较高,且存在较丰富的甲基甾烷和甲藻甾烷。芳烃馏分中含硫芳烃相对丰度较高,烷基二苯并噻吩与烷基二苯并呋喃丰度比值明显高于正常腐殖煤。上述特征表明,库车坳陷中生界中这类腐殖煤具有海相或盐湖相沉积的特点。由于腐殖煤形成于温暖潮湿的气候条件,因此,成煤环境水体咸化的原因主要是受海侵事件中海水作用的影响。The organic petrology and organic geochemistry are systematically studied on the coal measure source rocks in Late Triassic-Jurassic to find out the origin of the Mesozoic strongly reducing humic coal in Kuqa Depression,Tarim Basin and explore its special sedimentary environment.The results show that although the maceral composition is typical humic coal,the biomarker composition differs from that of normal humic coal.It has low Pr/Ph(pristane/phytane)value,regular and irregular isoprenoid alkanes with high carbon numbers developed,relatively high tricyclic terpenes in terpenoid composition,and high relative abundance of gammacerane.A relative abundance of C27 regular steranes is high in the sterane,and there are abundant methylsteranes and dinoflagellanes.The relative abundance of sulfur-containing aromatics in aromatic fractions is higher,and the abundance ratio of alkyl dibenzothiophene to alkyl dibenzofuran is significantly higher than that of normal humic coal.The above characteristics indicate that the humic coal in the Mesozoic of the Kuqa Depression has the characteristics of marine facies or salt lake facies deposition.Since humic coal was formed in a warm and humid climate,the salinity of the water in the coal-forming environment is mainly influenced by the action of sea water during the transgression event.

关 键 词：煤系烃源岩 腐殖煤 生物标志化合物 成煤环境 海侵事件 库车坳陷 

分 类 号：P618.13[天文地球—矿床学]