南华北东部徐淮地区新元古界生烃潜力分析

通过地层特征、有机地球化学指标和岩相古地理的分析,研究了南华北东部(徐淮地区)新元古界作为烃源岩及形成原生油气藏的可能性。结果表明:徐淮地区新元古界有机质丰度低,母质类型为Ⅰ型干酪根,热演化程度处于成熟—过成熟阶段; 自下而上可划分为青白口系刘老碑组和南华系贾园组—魏集组两套烃源岩,后者又细分为贾园组—九顶山组和张渠组—魏集组两套烃源岩,均仅达到较差烃源岩标准。从烃源条件来看,刘老碑组、张渠组—魏集组和贾园组—九顶山组依次变差; 淮北地区比淮南地区更有利。建议该区有利含油气远景区段为蚌埠古隆起周边地带的低热演化区块。

Hydrocarbon-generating potentials of the Neoproterozoic in Xuhuai area, the east part of southern North China

Based on the synthetical analyses of stratigraphic characters,organic geochemical indexes and lithofacies paleogeography,the probability of the Neoproterozoic source rocks and primary petroleum reservoirs in Xuhuai area was discussed.Xuhuai area locates in the east part of southern North China and is divided into Huainan and Huaibei district by Bengbu-Jieshou ancient uplift.Lower mudstones of Liulaobei Formation and upper carbonates of Jiayuan to Weiji Formation reached just the standard of hydrocarbon source rocks,and the latter could subdivided into Jiayuan to Jiudingshan Formation and Zhangqu to Weiji Formation.The Neoproterozoic source rocks contain low abundance of organic matter and Ⅰ-type kerogen with the mature to over-mature stages of thermal evolution.The hydrocarbon source quality of Liulaobei Formation,Zhangqu to Weiji Formation and Jiayuan to Jiudingshan Formation become worse in turn,and the Huaibei district was better than the Huainan district.The surrounding area of Bengbu-Jieshou ancient uplift with lower thermal evolution is favorable prospect areas.