陕北地区石炭—二叠系天然气富集条件的认识

RECOGNITION ON NATURAL GAS ENRICHMENT FACTORS IN CARBONIFEROUS-PERMIAN SYSTEM AT SHAANBEI AREA

陕北地区天然气勘探成果表明,石炭—二叠系各层段均发现了气层或含气显示,具备了天然气富集成藏的基本地质条件。认为其天然气富集的主要条件是烃源岩的展布范围和生烃能力、有利沉积相砂体、现今低隆起构造部位所形成的岩性圈闭或岩性—构造圈闭、生排烃时间和流体运聚指向区域,这些有利油气地质条件的配置构成了天然气富集区并控制了气藏的分布。

On the basis of natural-gas exploration,gas layers or gas shows found in Carboniferous-Permian system at Shaanbei area belong to Yanchang Petroleum Group,with favorable geological conditions of emerging gas resources.The main natural gas accumulation and resources are located the region of source rocks with ability of hydrocarbon generation,advantageous sedimentary sand bodies,structure of lower upheaval,rocky traps at present or rocky-structural traps,the time of emerging and expelling hydrocarbon,and the regions of liquid accumulation,reasonable collocation of all these conditions make up advantageous areas and control the distribution of gas resources.