摘要
武威盆地发育厚度近千米的石炭系,具东厚西薄的特点,是一套海陆交互相碎屑岩、碳酸盐岩及含煤沉积。早石炭世早期前黑山组沉积时期,仅在盆地南部接受沉积,厚度为100~150 m,气候炎热干旱,以滨浅海和咸化泻湖环境为主,主要沉积了杂色碎屑岩,夹白云岩和石膏沉积,生油能力差;下石炭统上段臭牛沟组—上石炭统靖远组、羊虎沟组、太原组沉积时期,气候温暖湿润,海侵范围扩大,盆地内均有沉积,厚度为300~800 m,为滨浅海、滨海沼泽、淡化泻湖、三角洲环境,形成了暗色泥岩、页岩、炭质泥岩、灰岩烃源岩,盆地周缘石炭系烃源岩有机质丰度较高,属中等—好烃源岩,是盆地内主要的生油气源岩,发育自生自储式生储盖组合。综合分析表明武威盆地是一个有潜力的含油气盆地。
Carboniferous system in Wuwei basin,developing a coal-bearing deposition with a thickness near 1000m,is a set of sedimentary strata of paralic clastic rocks and carbonate rocks.During the sedimentary period of Qianheishan Formation in early stage of Early Carboniferous,the Carboniferous strata only deposited in southern Wuwei basin with thickness of 100-150m.Due to the hot and dry climate,the depositional environment was mainly of salty lagoon and littoral-neritic facies.And the deposits were primarily composed of mottled clastic rocks,dolomite interlayer and gypsum which are poor source rocks.During the period of Chouniugou Formation in late stage of Early Carboniferous to Jingyuan Formation,Yanghugou Formation and Taiyuan Formation in Late Carboniferous,the climate changed to warm and humid,and the ingression range extended.Then the depositional thickness increased to 300-800m,with a sedimentary environment of desalting lagoon,littoral marsh,delta,littoral and neritic deposit.The main rocks were dark mudstone,shale,carbonaceous mudstone and limestone source rock.The organic content was much higher in carboniferous hydrocarbon source rocks around Wuwei basin,which was the main hydrocarbon-bearing source rocks in the basin,with the source-reservoir-cap assemblage of self-generation and self-accumulation.It can be concluded that Wuwei basin is a potential hydrocarbon-bearing basin.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2011年第2期267-274,共8页
Natural Gas Geoscience
关键词
沉积环境
含油气远景
石炭系
武威盆地
Sedimentary environment
Oil and gas potential
Carboniferous
Wuwei basin.
