塔里木盆地西部环阿瓦提凹陷区油气勘探前景再认识

Re-cognition on Petroleum Exploration Prospect of Marine Carbonates in Western Tarim Basin

塔里木盆地台盆区震旦系到侏罗系的多个目的层中发现油气,显示了其良好的勘探前景。但从东西方向上看,目前发现的油气田主要分布在盆地东部的环满加尔凹陷区。处在盆地西部的环阿瓦提凹陷区尽管投入了一定的勘探工作量,但一直没有重大发现。井下和地面露头资料揭示,环阿瓦提凹陷区具有良好的油气源条件。寒武系—奥陶系碳酸盐岩、志留系—三叠系碎屑岩都是值得重视的勘探目的层。其中碳酸盐岩储层,不仅具有发育礁滩的古地理背景,同时还具有热液改造的条件;对于碎屑岩而言,断层沟通可能是其捕获油气的关键。

A series of significant discoveries from Sinian to Jurassic in multiple target layers exploration has exhibited great prospect of petroleum exploration in Tarim Basin. Comparing the present discoveries in the eastern basin with those in the western basin, it is shown that most of the oil and gas fields distribute around Mangar Sag in the eastern basin. Some workloads of exploration were put but no large oil or gas field has discovered around Awati Sag in western basin. InformatiOn from well logs,cores and outcrops reveals fine oil and gas source conditions around Awati Sag. The Cambrian-Ordovician carbonate rock and Silurian-Tnassic clastic rock are all the noticeable target layers. For the carbonate reservoirs, it has not only the paleo-geography background of the reefshoal but also thermal liquid condition; while for the clastic rock reservoirs, fault may be the key to trap oil and gas. It is necessary to further study systematically and evaluate entirely the prospects of areas around Awati Sag in aspects of source rock evolution, resource potential, reservoir distribution and the main controlling factors.