崖13-1大气田形成的地质条件

GEOLOGIC SETTINGS FOR YA 13-1 GIANT GAS FIELD FORMATION

文章简要地介绍了崖13-1气田的地质特征、区域构造和沉积背景.着重叙述了气田形成的有利条件:崖城组气源丰富,大量生气时间晚、速率高,岩性组合有利于生排烃;主力储气层陵三段砂层属扇三角洲沉积体系;具背斜形态、圈闭面积较大、幅度高;梅山组岩性致密.分布稳定为区域盖层,对气层具岩性—压力双重封闭作用;圈闭形成期早于大量生气期;生储层之间的不整合,使运移通道范围大、距离短;气田保存条件好。

Authors give a brief introduction of geologic characters and tectonic—sedimentary features of Ya 13—1 gas field and emphasize the following favourable conditions for the gas field formation. 1. A rich gas source rock of Yacheng formation generated massive gas at proper time and high rate, and lithologic combination favored gas (oil) generation and migration. 2. The main pay zones belong to fan delta systems and are of syndepositional anticlinal geometry with large entrapment. 3. A lithology—pressure double seal presents as Meishan formation. the regional seal,has very dense lithology and regional continuity.4.Trap formation predated the significant gas generation. 5. The unconformable contact between the reservoir and source rock favors short distance migration. 6. Good preservation of the gas pools exists.