地质论评2026，Vol.72Issue(1)：199-211,13.DOI:10.16509/j.georeview.2025.07.011
柴达木盆地中侏罗统致密油成藏控制因素分析
Analysis of controlling factors of tight oil accumulation in Middle Jurassic in Qaidam Basin
摘要
Abstract
Objectives:The Middle Jurassic strata in the Qaidam Basin exhibit favorable geological conditions for tight oil accumulation,but the main controlling factors for large-scale exploration and development remain unclear. Methods:Through analyses of organic geochemistry,reservoir physical properties,and homogenization temperature tests of fluid inclusions from core/cuttings of six wells(e.g.,the Well Long-2 and Chaiye-1 in the Yuqia Sag,northern Qaidam Basin),this study investigates the characteristics of hydrocarbon source rocks and tight reservoirs in the Middle Jurassic Dameigou Formation,as well as the source-reservoir coupling relationships and their control on hydrocarbon accumulation. Result:The results indicate that the main hydrocarbon source rocks of the Dameigou Formation are primarily developed in the J2d7 segment.Tight delta-front distributary channel siltstone reservoirs interbedded with these source rocks exhibit excellent source-reservoir configurations.The J2d7 segment serves as the primary accumulation layer for tight oil in the Middle Jurassic of the Yuqia Sag.The reservoir densification occurred approximately 30 Ma ago,while hydrocarbon charging and accumulation took place about 3.29 Ma ago,representing a single-phase charging and one-stage accumulation process. Conclusion:The thermal maturity of the source rocks controls the distribution of Middle Jurassic tight oil in the northern Qaidam Basin.Late Jurassic-Cretaceous compressional inversion and intense uplift during the late Neogene led to significantly lower thermal evolution degrees of Middle Jurassic source rocks in the Yuqia Sag compared to other hydrocarbon-generating sags in northern Qaidam.Prospective exploration areas for Middle Jurassic tight oil include the Qianxi region,Hongshan Sag,and southwestern Yuqia Sag in the northern Qaidam Basin.关键词
致密油/柴北缘/中侏罗统/鱼卡凹陷/大煤沟组/成藏控制因素Key words
tight oil/northern edge of Qaidam Basin/Middle Jurassic Series/Yuqia Sag/Da Meigou Formation/major contributing factors of reservoir forming引用本文复制引用
周志,任收麦,赵为永,姜振学,包书景,王胜建..柴达木盆地中侏罗统致密油成藏控制因素分析[J].地质论评,2026,72(1):199-211,13.基金项目
本文中国地质调查局资助项目(编号:1212011221045、12120113040000)的成果. This study is supported by projects funded by the China Geological Survey(Nos.1212011221045,12120113040000).Prof.QIAO Dewu from the Oil and Gas Resources Strategy Research Center of the Ministry of Natural Resources provided constructive suggestions for this article （编号:1212011221045、12120113040000）
Prof.SUN Weilin from the National Geological Experiment and Testing Center and Prof.OU Guangxi from the Beijing Research Institute of Nuclear Industry Geology provided strong support for the experiments and tests.We would like to express our gratitude to all of them here. （）
