苏北盆地溪桥含氦天然气田地质特征及含氦天然气勘探前景

Geological character of Xiqiao helium bearing gas field and prospecting of helium bearing natural gas in North Jiangsu basin.

苏北盆地具有聚集含氦天然气的特殊地质条件，在盆地的若干气井或气田（ 藏） 中较普遍地发现了氦。溪桥气田为苏北盆地首次发现的含氦天然气田，含氦量为０．５８ ％ ～１ ．０６％ ，达到或超过氦工业品位（ 含氦量为０．３ ％ ）；气田地质时代较新，储集层为上第三系砂岩；气藏埋藏浅，气层埋深仅３８０ｍ 。气田中的氦以幔源为主，与氮及无机成因的ＣＯ２ 相伴生。含氦气田叠覆于以海相地层为储集层的大型ＣＯ２ 气田之上，两者具有一定的成生联系，该气田的发现表明苏北盆地具有良好的含氦天然气勘探前景。图４ 表２ 参３（ 郭念发摘）

There are some specially geologic ground for accumulation of helium bearing natural gas in North Jiangsu basin, in which helium is universally found in some gas wells or gas fields, of which helium content of Xiqiao gas field is obviously great, more then 0.58% 1.06%, reaching or exceeding pay grade of helium (≥0.3%). Therefore, it is the first helium bearing gas field found in North Jiangsu basin. The origin of gas field is relatively late and its sandstone reservoir is Neogene stratum, and its gas layer is relatively shallow and less than 380m in deep. Helium is mainly originated from mantle, companying with nitrogen and inorganic carbon dioxide. The gas field lies on a great carbon dioxide gas field whose reservoir is marine stratum, tow gas fields contain some identical origin character. The discovery of Xiqiao helium bearing gas field demonstrates North Jiangsu basin having favorable prospects for exploring helium bearing gas.