谭庄-沈丘凹陷精细油源对比

Comparison on fine oil source correlation in TanzhuangShenqiu sag

谭庄-沈丘凹陷油气显示活跃,具有显示井多、层位全的特点,区内22口探井中有16口井在石炭-二叠系、下白垩统、古近系和新近系见到不同级别的油气显示。根据原油的宏观物理特征、化合物组成、原油与石炭二叠系、下白垩统烃源岩的轻烃组分和生物标志化合物指标进行油源对比,认为谭庄-沈丘凹陷下白垩统原油具有混源特征,其中原油重烃组分来自下白垩统永丰组下段暗色泥岩,原油轻烃组分来自于上古生界煤层和暗色泥岩。研究表明下白垩统和石炭二叠系是本区主要的勘探目的层系,下白垩统自生自储型和古生中储型成藏组合是重要的勘探领域,对下步勘探部署具有重要的指导作用。

Hydrocarbon show in Tanzhuang-Shenqiu sag indicates active hydrocarbon and displays the characteristics of multiple wells and whole horizons.There are 22 exploration wells in the area and different levels of oil and gas shows can be seen in 16 wells in permo-carboniferous,lower cretaceous,paleogene and neogene.According to the physical characteristics of crude oil,compounds,crude oil,and the oil sources correlation of light hydrocarbon components and biomarker compound indexes of carboniferous Permian and lower cretaceous hydrocarbon source rocks,the crude oil in lower cretaceous is of mixed source characteristics.Among them,the heavy hydrocarbon component of crude oil is from the lower cretaceous Yongfeng formation under the period of dark mudstone,and the light hydrocarbon component of crude oil is from coal and dark mudstone in upper palaeozoic.Studies have shown that lower cretaceous and the carboniferous Permian is the main exploration target strata in this area,and the self-generated and the lower cretaceous and the Paleozoic source-mesozoic reservoir accumulation combination is an important exploration area,which can provide important guiding role for gas exploration deployment in the next step.