海相油气地质2024，Vol.29Issue(1)：45-56,12.DOI:10.3969/j.issn.1672-9854.2024.01.004
北羌塘坳陷东缘上三叠统巴贡组海相烃源岩特征及勘探启示
Characteristics of marine source rock of Bagong Formation and exploration significance in the eastern margin of North Qiangtang Depression,Qiangtang Basin
摘要
Abstract
The Qiangtang Basin,located in the eastern part of the Tethys domain,is the only large-scale superimposed basin in China where no industrial oil or gas fields have been discovered.Based on the new round of comprehensive research on oil and gas geology in recent years,a set of widely distributed black mudstone with large thickness(600-800 m)of Bagong Formation is found being developed in the front delta-shallow water shelf during the foreland basin stage of Late Triassic in Qiangtang Basin,which is of great significance for oil and gas exploration.In order to study the organic geochemical characteristics of the black mudstone of Bagong Formation in the eastern margin of the North Qiangtang Depression,61 core samples from shallow well and 64 hand-drilled plunger samples are collected to carry out geochemical and mineralogical analysis,and the source rock potential and sedimentary environment are evaluated.The results show that:(1)The black mudstone of the Bagong Formation,with TOC of 0.06％-5.81％,is poor-medium source rock on the whole,and some reach the standard of high-quality.Formed in weak oxidation-weak reduction environment,the organic matter type is Ⅱ2―Ⅲ,mainly belonging mixed organic matter.It is in the late mature to high mature stage with Ro of 0.95％-1.90％.(2)The Bagong source rock has great hydrocarbon generation potential,due to high organic matter abundance,good organic matter type,and moderate maturity.(3)There developed a source-reservoir assemblage of"lower generation and upper reservoir"between the Bagong source rock and the glutenite reservoir at the bottom of the Quemocuo Formation,which lays a foundation for the formation of large and medium-size oil and gas fields.Besides,the Bagong mudstone is a favorable layer for shale oil exploration.In general,the Bagong source rock is of great significance for conventional and unconventional oil and gas exploration in the eastern margin of the North Qiangtang Depression.关键词
烃源岩/有机地球化学/生烃潜力/勘探领域/巴贡组/北羌塘坳陷Key words
source rock/organic geochemistry/hydrocarbon potential/exploration field/Bagong Formation/North Qiangtang Depression分类
能源科技引用本文复制引用
宁生伟,谢渊,付小东,宋春彦,刘琪,熊绍云..北羌塘坳陷东缘上三叠统巴贡组海相烃源岩特征及勘探启示[J].海相油气地质,2024,29(1):45-56,12.基金项目
本文受中国石油"十四五"前瞻性基础性重大科技项目所属课题"羌塘盆地油气成藏、资源潜力与战略选区研究"(编号:2021DJ0802),西藏科技厅重点研发计划"基于多源信息的羌塘盆地断裂保存条件及油气勘探选区研究"(编号:XZ202101ZY0014G),西藏自治区科技重大专项"羌塘盆地新生代岩浆活动、隆升运动和地热活动对油气的影响"(编号:XZ202201ZD0004G05)联合资助 （编号:2021DJ0802）
