中国海相油气田勘探实例之七塔里木盆地和田河气田的勘探与发现

和田河气田位于新疆塔里木盆地中央隆起巴楚凸起南缘的玛扎塔格构造带,含气面积143.45km2。气田发现于1997年9月,是塔里木盆地已探明的最大的古生界海相碳酸盐岩气田,1998年探明天然气地质储量616.94×108m3。气田由七个气藏构成,气源为寒武系海相碳酸盐岩烃源岩形成的古油藏油裂解气和过成熟干酪根裂解气的混合气,主力产气层为奥陶系碳酸盐岩潜山以及石炭系海相碳酸盐岩和碎屑岩,它们与各自上覆的石炭系不同泥岩段构成良好的区域性和区带性储盖组合。论述了气田的勘探和发现历程、气藏的主要地质特征,总结了应用油气晚期成藏理论取得油气突破的勘探实践与认识启示。

Cases of Discovery and Exploration of Marine Fields in China (Part 7): Hotanhe Gas Field in Tarim Basin

Hotanhe Gas Field is located in the southern margin of Bachu Swell of Zhongyang Uplift, Tarim. The field is named from Hotan River that passes through it. It is discovered in September 1997 and began to yield commercial gas for the local use in 1998. It is the largest gas field of marine carbonate rock in Tarim Basin, which covers a gas area of 143.45km2 and holds 61.694×109m3 of proved reserves in-place. The fields include seven gas reservoirs. The produced mixed gas derived from both, the gas cracked from the oil in the Cambrian carbonate paleo-reservoir, and the gas directly cracked from overmatured kerogen in the Cambrian carbonate source rock. Main gas pays are the Ordovician carbonate buried hill and Carboniferous marine carbonate and clastic rock reservoirs. These reservoirs and their own overlying Carboniferous mudstone beds constitute several good regional and zoned reservoir-cap assemblages. We reveal the exploration history of the field, the geological characteristics of the reservoir and conclude how to take out the breakthrough of exploration by the theory of late hydrocarbon accumulation.