地球学报2025,Vol.46Issue(3):587-601,15.DOI:10.3975/cagsb.2024.100901
羌塘盆地东部上二叠统海陆交互相烃源岩特征及勘探前景
Characteristics and Exploration Prospects of the Upper Permian Marine Land Interacting Source Rocks in the Eastern Qiangtang Basin
摘要
Abstract
The focus on hydrocarbon source rocks in the Qiangtang Basin has for a long time been mostly on the Mesozoic strata.However,in recent years,many oil and gas discoveries have been made in the Upper Permian sequences of the Qiangtang Basin,indicating good oil and gas potential.To identify the source rock conditions of the Upper Permian in greater detail,dark mudstone samples from six profiles and one drilling well in the Upper Permian Nayixiong Formation were analyzed using organic geochemical methods.The results of the samples studied show that the abundance of organic matter in the formation is relatively high,with much of it reaching the standard of source rocks and containing a considerable amount of high-quality source rock(TOC>2%).The types of organic matter are mainly types II2 and III,with a small amount of type II1.Its parent material exhibits mixed source characteristics,with greater contributions of aquatic plankton and algae and a certain input from terrestrial plants.These source rocks accumulated mostly in a reducing environment,and some of them formed in an anoxic environment with hypersaline waters.The degree of thermal evolution of the organic matter has reached the mature stage,and it mainly falls into the high-maturity to over-mature conditions,which are prone to the generation of condensate oil and moisture.The results indicate that the Upper Permian Nayixiong Formation has good hydrocarbon generation ability and that the quality of the superjacent bioclastic limestone reservoir is good.Both the source rocks and the reservoir form a favorable oil and gas system and have good oil and gas exploration potential.关键词
羌塘盆地/上二叠统/那益雄组烃源岩/勘探前景Key words
Qiangtang Basin/Upper Permian/Nayixiong Formation source rock/exploration prospects分类
地质学引用本文复制引用
孙伟,任柳洁,占王忠,谢尚克,杨平,胡作维,曾胜强,侯乾,宋春彦..羌塘盆地东部上二叠统海陆交互相烃源岩特征及勘探前景[J].地球学报,2025,46(3):587-601,15.基金项目
本文由国家自然科学基金项目(编号:42172134)、中国地质调查局地质调查项目(编号:DD20221661 (编号:42172134)
DD20230266)和中国石油化工股份有限公司勘探分公司项目(编号:35450003-23-ZC0607-0018)联合资助. This study was supported by National Natural Science Foundation of China(No.42172134),China Geological Survey(Nos.DD20221661 and DD20230266),and Sinopec Exploration Company Research Project(No.35450003-23-ZC0607-0018). (编号:35450003-23-ZC0607-0018)