塔里木盆地——富含天然气的盆地

TALIMU BASIN RICH IN NATURAL GAS

近年来，塔里木盆地油气勘探取得很大突破。盆地发育有三套重要的烃源岩：寒武系烃源岩由于处于高—过成熟阶段，在晚近期以形成天然气为主；中—上奥陶统烃源岩由于其特殊的生烃母质类型而既能生油又能生气；侏罗系则由于其属于腐殖型烃源岩而以生成天然气为主。盆地在资源分布上具有富含气的特征。气源对比结果表明，塔里木盆地目前发现的天然气主要源自上述３套重要的烃源岩。盆地内广泛发育的５套区域盖层是形成大型、特大型天然气藏的必要条件。因此，从生成和保存两方面说明塔里木是一个富含天然气的盆地。“八五”期间，塔里木盆地探明天然气储量１０９２．３６×１０８ｍ３、凝析油３８４５．３×１０４ｔ（塔指探区）。这说明塔里木盆地除了富含原油外，同时也是一个富含天然气的叠合、复合盆地。

In recent years, a great progress has been made in gas exploration in Talimu Basin. There are three sets of important hydrocarbon source rocks in the basin, i.e. the Cambrian source rocks which mainly generated gas in late period because of their high and post maturity, the Middle and Upper Ordovician source rocks which generated not only oil but also gas because of their special kerogen, and the Jurassic source rocks which mainly generated gas because of their humic type kerogen, therefore this basin is rich in gas resources. Through gas source correlation, it is shown that the natural gas found in Talimu Basin at present is mainly derived from the three sets of significant hydrocarbon source rocks mentioned above. The necessary condition of forming giant or supergiant gas reservoir is the five sets of regional cap rocks widely distributed over the basin. According to both generation and preservation, the Talimu Basin is rich in natural gas. During the “Eighth Five Year Plan”, the proved gas reserves of 1092.36×10 8m 3 and condensate reserves of 3845.3× 10 4t were found in the basin (the exploration regions belonging to the Talimu Petroleum Exploration and Development Headquarters). This indicates that the Talimu Basin is a superposed and composite basin rich in not only oil but also natural gas(being mainly condensate gas).