准噶尔盆地古城凹陷中二叠统芦草沟组烃源岩生烃潜力  

Hydrocarbon-generating potential of the Middle Permian Lucaogou source rocks in the Gucheng Sag,Junggar Basin

作　　者：龚德瑜 韩琰 范谭广[3] 李新宁[3] 周川闽[1] 王绍清[2] 王瑞菊[1] 吴卫安[1] 苗一豪 GONG Deyu;HAN Yan;FAN Tan’guang;LI Xin’ning;ZHOU Chuanmin;WANG Shaoqing;WANG Ruiju;WU Wei’an;MIAO Yihao(Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;School of Geosciences and Surveying and Mapping Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Research Institute of Exploration and Development,Tuha Oilfield Company,PetroChina,Hami 839009,China;School of Energy College,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [3]中国石油吐哈油田公司勘探开发研究院,新疆哈密839009 [4]中国地质大学(北京),北京100083

出　　处：《天然气地球科学》2025年第1期57-71,共15页Natural Gas Geoscience

基　　金：国家自然科学基金项目(编号:42272188);中国石油前瞻性基础性技术攻关项目(编号:2021DJ0206;2022DJ0507);中国石油直属院所基金项目(编号:2020D⁃5008⁃04)联合资助.

摘　　要：位于准噶尔盆地东部隆起的吉木萨尔凹陷发现了十亿吨级特大型页岩油田,揭示出中二叠统芦草沟组烃源岩良好的生烃潜力。研究系统评价了与吉木萨尔凹陷邻近的古城凹陷芦草沟组烃源岩的生烃潜力和形成环境,刻画了烃源灶的分布范围,并与吉木萨尔凹陷芦草沟组烃源岩进行了对比。结果表明:古城凹陷芦草沟组烃源岩干酪根类型主要为Ⅱ/Ⅲ—Ⅲ型,以好—极好烃源岩为主,类型和丰度略逊于吉木萨尔凹陷。中—晚侏罗世,古城凹陷芦草沟组烃源岩整体进入生烃门限,现今进入主生油窗的面积为212 km^(2)。尽管均为湖相沉积,相较于吉木萨尔凹陷,古城凹陷芦草沟组烃源岩的Pr/Ph、Ts/(Ts+Tm)、C_(19)/C_(21)三环萜烷、C_(24)四环萜烷/C_(26)三环萜烷值相对略高,C_(28)规则甾烷含量略低,说明其沉积于具有一定盐度的氧化—还原过渡环境,除藻类和微生物生源的贡献外,还有一定数量的陆源高等植物输入。古城凹陷芦草沟组烃源岩发育4个大于160 m的厚度中心,总面积约为420 km^(2),在凹陷南部发育3个生油强度大于200×10^(4)t/km^(2)的生烃中心,总面积为130 km^(2)。研究成果进一步夯实了准噶尔盆地中二叠统含油气系统的资源基础,也为古城凹陷下一步油气勘探工作奠定了基础。A billion-ton shale oil field was discovered in the Jimsar Sag,located in the East Uplift of Junggar Ba⁃sin,revealing the favorable hydrocarbon-generating potential of the source rocks developed in the Middle Perm⁃ian Lucaogou Formation.In this study,the hydrocarbon-generating potential and sedimentary environment of the Lucaogou source rocks in the Gucheng Sag,neighboring to the Jimsar Sag,were evaluated systematically,and the distribution range of the source kitchen was depicted.In addition,the characteristics of the Lucaogou source rocks in the Gucheng Sag were compared with those in the Jimsar Sag.The results show that the Lucao⁃gou source rocks in the Gucheng Sag are characterized by kerogen typesⅡ/Ⅲ-Ⅲand are good to excellent source rocks whose organic types and abundance are slightly inferior to those in the Jimsar Sag.In the Middle to Late Jurassic,the Lucaogou source rocks in the Gucheng Sag generally entered the hydrocarbon-generating threshold,and the area entering the main oil-generating window reaches 212 km^(2)at present.Although they were both deposited in a lacustrine environment,the ratios of Pr/Ph,Ts/(Ts+Tm),C_(19)/C_(21)tricyclic ter⁃penes,C_(24)tetracyclic terpenes/C_(26)tricyclic terpenes in the Lucaogou source rocks in the Gucheng Sag are slight⁃ly higher than those of the Lucaogou source rocks in the Jimsar Sag,and the relative content of C_(28)regular ster⁃anes is slightly lower.This indicates that the Lucaogou source rocks in the Gucheng Sag were deposited in an oxidation-reducing transitional brackish environment with a certain number of terrigenous higher plant inputs in addition to the contribution of algae and microorganisms.Four thickness centers of the Lucaogou source rocks with more than 160 m thickness were developed in the Gucheng Sag,covering a total area of 420 km^(2).Three hy⁃drocarbon-generating centers with an oil-generating intensity greater than 200×10^(4)t/km^(2)were developed in the southern part of the sag with a total area of 130 km^(2).The researc

关 键 词：准噶尔盆地 古城凹陷 芦草沟组 生烃潜力 生物标志物 烃源灶 

分 类 号：TE122.113[石油与天然气工程—油气勘探]