广西潞城深水沉积地层构型特征及其石油地质意义

Stratigraphic configuration characteristics and their geologic significance of deep water deposits of Lucheng outcrop, Guangxi

广西田林潞城中三叠统深水沉积露头发育厚层砂岩相、中厚层砂岩相、薄层砂岩相、砂质条带岩相、块状泥岩相、薄层泥岩相和中厚层泥岩相等7种岩石相类型。根据砂岩和泥岩的组合关系,在剖面上识别出了厚层砂岩相和块状泥岩相组合、厚层砂岩相和薄层泥岩相组合、中厚层砂岩相和薄层泥岩相组合、中厚层砂岩相和中厚层泥岩相组合、薄层砂岩相和薄层泥岩相组合、薄层砂岩相和中厚层泥岩相组合及中厚层泥岩夹砂质条带组合等7种岩石相组合。深水沉积地层具有千层饼式的地层构型特征,发育了厚层砂岩叠置样式、厚层和中厚层砂岩叠置样式、中厚层砂岩叠置样式、中厚层和薄层砂岩叠置样式、薄层砂岩叠置样式、薄层砂岩和泥岩叠置样式及泥岩夹砂质条带样式等7种地层构型样式。深水沉积虽然构型样式简单,但有着十分复杂的储层非均质性,既有可能形成常规油气藏,也有可能形成非常规油气藏。上述认识对深水沉积油气勘探开发具有一定的指导意义。

Seven lithofaciese including thick sand, middle-thick sand, thin sand, sandstripe, massive mudstone, thin mudstone and middle-thick mudstone developed on the outcrop of deep water deposits at Lucheng of Tianlin county in Guangxi. Every two of these lithofaciese combined into a lithofacies assemblage, thus there are 7 lithofacies assem- blages can be recognized, including thick sand and massive mudstone, thick sand and thin mudstone, middle-thick sand and thin mudstone, middle-thick sand and middle-thick mudstone, thin sand and thin mudstone, thin sand and middle-thick mudstone, as well as middle-thick mudstone with striped sand. The assemblages then superimposed one by another to form 7 patters of the layer cake typed stratigraphic configuration, including stacked thick sand, stacked thick sand and middle-thick sand, stacked middle sand, stacked middle sand and thin sand, stacked thin sand, stacked thin sand and mudstone, mudstone with striped sand. Although the configuration of deep water deposits is simple, it has complex reservoir heterogeneity, and it can forms both conventional and unconventional reservoirs. These cognitions have great significance for hydrocarbon exploration and development of deep water deposits.