鄂尔多斯盆地奥陶系盐下天然气勘探

Exploration of Ordovician Subsalt Natural Gas Reservoirs in Ordos Basin

鄂尔多斯盆地中东部地区下古生界奥陶系发育多套巨厚的盐岩沉积,成藏条件好,因此,奥陶系盐下一直是勘探关注的重要领域,并对其进行了持续研究与不懈探索。鄂尔多斯盆地奥陶系盐下勘探几经周折,逐步形成了"上古生界煤系烃源岩侧向供烃、白云岩岩性圈闭成藏、区域岩性相变带多层系富集"的新认识。以新的地质认识为指导,在盆地中部的奥陶系马家沟组盐下终于获得了日产百万立方米以上高产工业气流井,开拓了该盆地又一个碳酸盐岩勘探新领域,证实奥陶系深层也具有良好的勘探潜力。

Many sets of huge-thick Ordovician salt anhydrite deposits of Lower Paleozoic developed in the eastern part of Ordos Basin with good conditions for accumulations. Therefore, Ordovician subsalt has been a focus of important exploration area that comes under a continuous study. Tenacious efforts for exploration of Ordovician subsalt in Ordos Basin lead to some new theories, such as 'lateral hydrocarbon supply from source rock of Upper Paleozoic coal measures, accumulations of dolomite lithologic trap, and multi-layer abundance in regional lithologic facies changing belt.' Based on guidance of new geological theories, a high-yield industrial gas fl ow of more than 1 million cubic meters per day was acquired from Ordovician subsalt Majiagou Formation in the central part of the basin, opening up another carbonate rock exploration fi eld in the region and confi rming the good exploration potential of Ordovician deep-layers.