贵州黔北地区页岩气成藏条件与勘探前景

页岩气作为非常规油气资源尤为重要的一种,具有特殊成藏机理,其成藏需要特殊的地质条件,主要受控于泥页岩厚度、有机质丰度、有机质成熟度、矿物岩石成分、压力和温度等因素。贵州黔北地区是我国南方下寒武统黑色岩系发育的典型地区之一,黑色岩系剖面露头良好,序列完整。具备有页岩气生成条件的泥页岩地层自下而上为震旦系陡山沱组、下寒武统牛蹄塘组与上奥陶统五峰组-下志留统龙马溪组地层。通过地质条件与地球化学综合分析,认为该地区的下寒武统牛蹄塘组黑色页岩系和上奥陶统五峰组-下志留统龙马溪组暗色泥页岩分布面积广泛,厚度较大,有机质含量和热演化程度高,是最为有利的页岩气勘探层位。

Reservoir forming condition and exploration prospect of shale-gas in Guizhou qianbei area

As an important one of unconventional oil and gas resources,the reservoiring mechanism of Shale gas is special,and it accumulates under special geological condition,controlled by the factors such as the thickness of the shale and mudstone,the content and the maturity of organic matter,mineral composition,the pressure and temperature of the formation.Guizhou Qianbei Area is one of the typical area developed Lower Cambrian black rock series in South China.The black rock series sections outcrops well and the sequence is complete.The formation that capable of accumulating shale gas are Sinian System Doushantuo Formation,Lower Cambrian Niutitang Formation and Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation.According to the integrate analysis of the Geochemical and Geological condition,the black shale series of Lower Cambrian Niutitang Formation and the dark shale and mudstone of Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation,which widely distributed,with high thickness,high content and maturity of organic matter,is the most favorable target for shale gas exploration.