江苏地区第四系浅层天然气的分布与勘探前景

DISTRIBUTION AND EXPLORATION PROSPECTS OF THE SHALLOW GAS IN THE QUATERNARY IN JIANGSU PROVINCE

江苏地区第四系浅层天然气显示十分广泛，大致可分为三个含气带：南京—上海沿江含气带，盐城—海安滨海含气带和淮阴—滨海古黄河含气带。在垂向上主要分布于第四系上更新统和全新统。通过近年来对该区浅层天然气的勘探与研究，认为浅层天然气来自第四系全新统的海相淤泥、粘土层，它们具有有机质丰度高、成气母质好的特征，形成途径以ＣＯ２还原而产生大量的生物甲烷气，因此这一浅层天然气实质上属于生物气。根据研究，预测江苏地区第四系浅层天然气的资源量为１０３．８１×１０８ｍ３，其中南京—上海沿江地区可达６９．３８×１０８ｍ３。

The shallow gas shows in the Quaternary are widely distributed over Jiangsu province,which may be roughly divided into three gas-bearing zones,i.e.Nanjing Shanghai along Yangtse river gas-bearing zone,Yancheng Haian seashore gas-bearing zone and Huaiyin Binhai ancient Huanghe river gas-bearing zone.The shallow gas is mainly found in the Upper Pleistocene and Holocene of the Quaternary vertically.Through the exploration and research on the shallow gas in this region in recent years,it is considered that the shallow gas comes from the marine silt and clay beds of the Holocene of the Quaternary which have the properties of high abundance of organic matter and fair kerogen of generating gas.Actually,such a shallow gas belongs to biogas,because large biogenic methane gas was generated through the way of reducing carbon dioxide.In light of the research achievements,it is predicted that the resource extent of the shallow gas in the Quaternary in Jiangsu province is 103.81×10.8m 3,in which the Nanjing Shanghai along Yangtse river region accounts for 69.38×10.8m 3.Therefore,this region is the advantageous area in the exploration for the shallow gas in the Quaternary in Jiangsu province.