湖南慈利灯影组古油藏的发现及意义

DISCOVERY OF DENGYLNG FORMATION FOSSIL POOL IN CILI, HUNAN AND ITS SIGNIFICANCE

赵宗举 冯加良 陈学时 周进高

Zhao Zhongju Feng Jialiang Chen Xueshi Zhou Jingao

湖南慈利南山坪乡上震旦统灯影组古油藏形成于晚志留世一早泥盆世时期,主要储集空间为灯影组白云岩因溶蚀作用形成的溶孔、溶洞和裂缝.晚侏罗世一早白垩世的燕山运动使其上覆盖层抬升、剥蚀,从而使其彻底破坏.该古油气藏的发现说明了湘鄂西坳陷具有与四川威远气田相似的生油及成藏过程,其主要区别在于威远气田后期受燕山运动的影响较小,而慈利古油气藏后期盖层破坏较大.因此,在湘鄂西地区,若能寻找到好的盖层和圈闭,有望发现类似而又未被破坏的南山坪上震旦统灯影组天然气藏.

The Dengying Formation fossil oil pool of Upper Sinian in Nanshanping, Cili County, Hunan Province was formed in Late Silurian-Early Devonian Period. The reservoir spaces were corroded pores,holes and fractures in Dengying Formation dolomite . The Late Jurassic-Early Cretaceous Yenshan movement caused the uplift and erosion of the covery bed of the fossil pool, thus resulting in complete damage of the pool. The discovery of the fossil pool suggests that West Hunan-Hubei Depression had similar hydrocarbon generation and pool-forming process as Weiyuan Gasfield, in Sichuan Province. The difference is that Yenshan movement had little influence on Weiyuan Gasfield, but the Cili fossil oil pool was seriously damaged by the movement. So it is considered that fovourable oil and gas pools could be found in Western Hunan-Hubei Region if favourable covety beds and traps could be found in the area.

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