吐哈盆地哈密坳陷石炭-二叠系油气成藏要素

Essential Factors of Carboniferous-Permian Hydrocarbon Accumulation in Hami Depression of Tuha Basin

借鉴三塘湖盆地火山岩油气勘探的经验,综合现有的地质、物探及钻井资料,从火成岩油气成藏的3个主控因素入手,分析评价哈密坳陷石炭-二叠系的油气成藏潜力后认为,哈密坳陷存在至少3套有价值的烃源岩,具有成藏的烃源岩基础;尽管石炭-二叠系储集层普遍较差,但部分探井揭示出火山岩原生储集层有被次生裂缝改善的迹象,目的层的后期浅埋以及古构造背景下后期的抬升遭一定程度的风化剥蚀等有利于火山岩的淋滤改造和储集层的发育,这种构造背景下控制的尤其是具有油气规模聚集的区域是下一步勘探的现实选择。

In this paper,the Carboniferous-Permian hydrocarbon accumulation potential in Hami depression of Tuha basin is analyzed starting with three main controlling factors that affect the volcanic reservoir,integrated with existing geologic,geophysical and drilling data and considering related explorative experiences in Santanghu basin.It suggests that there exist three sets of valuable source rocks in Hami depression;for all that the reservoir quality of the Carboniferous-Permian reservoirs is poor in general,some exploratory wells indicate that the primary volcanic reservoirs have partially been improved by secondary fractures and such factors as the later-stage shallow burying of target zones,the later-stage lifting under background of the paleo-structures and certain degree weathering and denudation,which are favorable for the leaching transformation and development of volcanic reservoirs.So the areas controlled by these factors could be the realistic targets for petroleum exploration in future.