中国海相油气田勘探实例之五 塔中奥陶系大型凝析气田的勘探和发现

Cases of Discovery and Exploration of Marine Fields in China (Part 5): Tazhong Ordovician Condensate Field in Tarim Basin

塔中奥陶系碳酸盐岩的勘探始于1989年,直至2005年发现塔中Ⅰ号坡折带奥陶系碳酸盐岩凝析气田,探明加控制石油地质储量1.5×108t(油当量),是我国目前发现的第一个奥陶系生物礁型大油气田。油气的主力产层位于上奥陶统良里塔格组上部,储层为受坡折带控制的陆棚边缘礁滩体石灰岩。油气沿坡折带呈带状展布,为整体含油的大型准层状岩性油气藏。论述了塔中碳酸盐岩大油气田的勘探历程、主要地质特征,以及对海相碳酸盐岩勘探的启示。

The exploration of Ordovieian carbonate rocks in Tazhong area began in 1989, but the large Ordovician Condensate Gas Field was discovered in TZ- Ⅰ Break Slope until 2005, in which there are more than 150 million tons of proved and controlled reserves in-place. The field is also the first Ordovician carbonate reef field in China. The main hydrocarbon pays are in the upper section of Lianglitage Formation （O2）. The reservoir is composed of limestone of shelf-edged carbonate reef bank which is controlled by the break slope. The oil reservoir is a large stratified lithologic trap in which hydrocarbon is distributed along the long and narrow TZ- Ⅰ Break Slope. The exploration history of the field, the geological characteristics of the reservoir and the revelation to exploration are revealed.