准噶尔盆地玛湖凹陷艾湖油田原油地球化学特征与油源对比  

Geochemical Characteristics and Oil-source Rock Correlation of Crude Oil in Aihu Oilfield,Junggar Basin

作　　者：朱涛[1] 李娜[1] 邹阳 刘国良[1] 赵毅[1] 周作铭[1] 王然[1] 刘新龙 绳智健 ZHU Tao;LI Na;ZOU Yang;LIU Guoliang;ZHAO Yi;ZHOU Zuoming;WANG Ran;LIU Xinlong;SHENG Zhijian(Research Institute of Exploration and Development,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000;Chinese Academy of Geological Sciences,Beijing 100037)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000 [2]中国地质科学院,北京100037

出　　处：《地球学报》2024年第6期1013-1022,共10页Acta Geoscientica Sinica

基　　金：中国石油天然气股份有限公司应用性科技课题“陆相页岩油分类评价与规模增储研究”(编号:2023ZZ15YJ01);自治区天山英才-科技创新领军人才支持项目“北疆地区二叠系超级盆地全油气系统地质理论研究与战略接替领域优选”(编号:2022TSYCLJ0070)。

摘　　要：玛湖凹陷作为准噶尔盆地重要富油气凹陷之一,油气藏主要分布在二叠系、三叠系和侏罗系,油气性质复杂。本次研究在前人工作基础上,以玛湖凹陷风城组(P1f)、夏子街组(P2x)、下乌尔禾组(P2w)和克拉玛依组(T2k)的烃源岩样品以及艾湖油田百口泉组(T1b)的原油样品为主要研究对象。通过TOC分析、岩石热解、碳同位素、饱和烃色谱、饱和烃色谱-质谱和单井埋藏史-热史的分析,明确玛湖凹陷百口泉组的原油来源问题。研究表明,玛湖凹陷风城组烃源岩有机质丰度明显优于下乌尔禾组烃源岩,且有机质丰度高,有机质类型以Ⅱ型干酪根为主,具有较高的生油潜力。百口泉组原油已达到成熟阶段,主要来源于弱氧化-弱还原的沉积环境。通过油源对比发现,玛湖凹陷原油与风城组烃源岩的生物标志物具有良好的可比性,反映了该地区原油主要来源于风城组烃源岩的贡献。且百口泉组油藏主要存在两期原油充注,分别为侏罗纪早期和白垩纪早期的原油充注,同风城组烃源岩生、排烃具有很好的耦合性。进一步佐证百口泉组原油来自风城组烃源岩这一观点。Mahu Sag,located in the Junggar Basin,is a significant oil and gas-rich sags primarily distributed in the Permian,Triassic,and Jurassic,exhibiting complex oil and gas properties.In this study,source rock samples of Fengcheng Formation(P1f),Xiazijie Formation(P2x),Lower Wuerhe Formation(P2w),and Karamay Formation(T2k)in Mahu Sag and the crude oil samples of Baikouquan Formation(T1b)in Aihu oilfield were used as the main research objects.Various analytival techniques,including TOC analysis,rock pyrolysis,carbon isotope,saturated hydrocarbon chromatography,saturated hydrocarbon chromatography-mass spectrometry,and single well burial history-thermal history analysis,were employed to clarify the crude oil source in Baikouquan of Mahu Sag.The results demonstrate that the organic matter abundance of Fengcheng Formation in Mahu Sag surpassed that of the source rock of Lower Wuerhe Formation,with abundant organic matter content.The organic matter in the studied formations is primarily identified as type II kerogen,indicating a high oil generation potential.The crude oil extracted from the Baikouquan Formation has reached maturity,and its origin can be attributed to the prevailing weak oxidation-weak reduction sedimentary environment.Through oil-source correlation,the crude oil biomarkers in Mahu Sag and Fengcheng Formation source rocks were found to be well comparable,underscoring the significant contribution of Fengcheng Formation source rocks to the crude oil in the area.Two distinct stages of crude oil filling were identified in the Baikouquan Formation reservoir.The first occurred during the Early Jurassic,while the second took place in the Early Cretaceous periods.Both stages are closely associated with hydrocarbon generation and expulsion within the Fengcheng Formation source rocks.

关 键 词：玛湖凹陷 艾湖油田 烃源岩 生物标志化合物 地球化学 油源对比 

分 类 号：P618.13[天文地球—矿床学]