济阳坳陷前古近纪烃源岩生烃潜力分析

济阳坳陷前古近系发育多套低勘探程度层系，下古生界寒武系—奥陶系、上古生界石炭系—二叠系和中生界都具有一定的生烃能力并可以提供油气资源。不同地质时期构造和沉积背景的差异形成了具有不同地球化学特征的烃源岩。本文综合地质资料、烃源岩热解和TOC分析资料、镜质体反射率资料、全岩显微组分分析资料、饱和烃和芳香烃色质资料等，系统分析了济阳坳陷前古近系烃源岩分布特征、地化特征和资源潜力。下古生界海相碳酸盐岩系烃源岩分布局限，有机质丰度较低，但类型较好，具有一定的供烃能力。上古生界煤系烃源岩分布范围广，有机质丰度较高，有机质类型相对较差，以生气为主，复杂的构造演化特征导致了这套源岩以二次生气为主。中生界发育了煤系源岩和湖相泥岩两套烃源岩，有机质类型中等，局部发育中等—好烃源岩，成熟度空间差异较大。总体来看，济阳坳陷三套前古近系烃源岩中，上古生界煤系源岩品质最佳，中生界次之，下古生界相对较差。

Hydrocarbon Generation Potential of Pre-Paleogene Source Rocks in the Jiyang Depression

Multiple sets of pre-Paleogene strata with relatively low exploration levels have developed in the Jiyang Depression. The Lower Paleozoic Cambrian-Ordovician, Upper Paleozoic Carboniferous-Permian and Mesozoic all host source rocks and thus can theoretically generate oil and gas for accumulation in the study area. Different tectonic and sedimentary backgrounds lead to different geochemical characteristics among different sets of source rocks. This study comprehensively analyzes  data of geology, source rock pyrolysis and TOC, vitrinite reflectance, whole rock microscopic composition, and gas chromatography-mass spectrometry of saturated and aromatic hydrocarbons. The distribution, geochemistry and resource potential of the pre-Paleogene source rocks in the Jiyang Depression were determined. The Lower Paleozoic marine carbonate source rocks have limited distribution and low abundance of organic matter, but have organic matter types favourable for certain hydrocarbon generation capacity. The widely distributed Upper Paleozoic coaly source rocks, with high abundance of organic matter and relatively poor organic matter types, are dominated by gas generation. As a result of complex tectonic evolution, this set of source rock is characterized by secondary hydrocarbon generation. The Mesozoic has developed two sets of source rocks (i.e., coaly source rocks and lacustrine mudstones) with medium organic matter types. Medium- to good-quality source rocks are developed locally with varying maturity spatially. Overall, among the thr ee sets of pre -Paleogene source rocks in the Jiyang Depression, the Upper Paleozoic coal-measure source rocks have the best quality, followed by the Mesozoic, and the Lower Paleozoic is relatively poor.