维也纳盆地石油地质特征与勘探潜力探讨

Petroleum Geology and Exploration Potential of Vienna Basin

通过分析维也纳盆地的地层和断裂发育特征,总结该盆地的石油地质特征,并对该盆地的勘探潜力进行探讨。维也纳盆地是位于东阿尔卑斯与西喀尔巴阡褶皱带之间的走滑拉分盆地,具有波西米亚和古生界至中生界双重基底,构造演化分为侏罗纪伸展断陷、白垩纪至早中新世逆冲推覆和中新世中期盆地拉分3个阶段。维也纳盆地自下而上形成3个构造层,分别为侏罗系至白垩系原地沉积层、二叠系至古近系外来推覆体沉积层和新近系沉积层。维也纳盆地发育上侏罗统泥灰岩和古近系页岩两套烃源岩,上侏罗统启莫里阶Malmian组泥灰岩是主要的烃源岩。储层分布于三叠系至新近系中新统的各个层段,其中最重要的储层为中新统浅水三角洲相砂岩,其油气储量占总储量的76%,其次为三叠系亮晶白云岩。区域盖层为新近系页岩。综合评价认为,中生界外来推覆体(复理石浊积岩和三叠系白云岩)和原地中生界沉积物(即第二、第三构造层)是最重要的勘探潜力区。

The oil geology feature of Vienna Basin was summarized and potential of exploration was discussed by analysising the strata of Vienna Basin and fracture development characteristics. Vienna Basin is a pull-apart basin located between the East Alps and West Carpathian. Its basement is composed of the Hercynian Bohemian Massif and Paleozoic and Mesozoic strata. The tectonic evolution can be divided into three stages, including Jurassic extensional rifting, Cretaceous-Early Miocene over-thrusting and Middle Miocene pull-parting stage. There are three structural lays from top to bottom, Jurassic-Cretaceous autoehthonous, Permian-Paleogene allochthonous Alpine nappes and Neogene sediments. There are two sets of source rocks： the upper Jurassic marls and Paleogene shale, among which, the Upper Jurassic Kimmeridgian Malmian marls are considered to be the major source rocks. Reservoirs occur at various horizons from Triassic to Neogene Miocene strata, among which, the most important reservoirs are Miocene sandstones that deposit in shallow-water delta environment and contain 76% of all reserves, and the minor reservoirs are the Triassic dolosparite. Neogene shales provide the regional top-seal. After evaluation, it is considered that Mesozoic allochthonous napps （flysch turbidite and Triassic dolomite） and Mesozoic autochthonous succession （the second and the third structural layer） are the most prospective for exploration.