北海盆地北部与南部油气成藏条件对比分析

Comparision and Analysis of Hydrocarbon Accumulation Conditions between the Southern and Northern the North Sea Basin

北海盆地为典型的中生代裂谷盆地,其油气的形成与分布具有较明显的特征。依据IHS数据库2009年提供的相关数据,结合生油层、储层、盖层及圈闭特征等方面的研究,对北海南、北盆地油气成藏条件进行了分析,认为其油气成藏条件存在较大的差异性。北北海盆地的主要油源岩为上侏罗统基末利黏土组页岩,南北海盆地主要气源岩为上石炭统威斯特伐利亚阶煤系地层;主要储层北北海盆地为中下侏罗统砂岩,南北海盆地为下二叠赤底统砂岩;北北海盆地区域盖层以泥、页岩为主,南北海盆地区域盖层为上二叠统盐岩;北北海盆地圈闭类型多样,而南北海盆地则类型较单一。控制其油气成藏条件差异性的主要因素是北海南、北盆地构造演化、沉积埋藏史和盐岩对油气成藏作用的不同。

North Sea basin is a typical Mesozoic rift basin, which the formation and distribution of oil and gas has obvious characteristics. Based on the data from HIS database 2009, combined with the generation, reservoir, cap rock and trap features research, the analysis of hydrocarbon accumulation conditions of the southern and northern the North Sea basin shows that there is difference between the southern and northern the North Sea basin. The main oil source rock of northern North Sea basin is the shale of Upper Jurassic Kimmeridge Clay. The main gas source rock of southern North Sea basin is Westphalian coal of Upper Carboniferous ; the main reservoirs of northern North Sea basin is Lower-Middle Jurassic sandstone, Lower Permian Rotliegende sandstone to south; the regional cap rock northern of North Sea basin is mudstone and shale, and halite to the south ; trap type of northern North Sea basin is variety, trap type of southern North Sea basin is single. The main factors for these difference are various structural evolution, sediment burial history and effect of Zechstein salt.