东营凹陷古近系碎屑岩成因类型及特征

Different sedimentary types of clastic rocks of the Paleogene in Dongying Sag

东营凹陷在古近纪湖盆演化各阶段发育了不同成因类型的碎屑岩储集体 ,其沉积相主要是冲积扇、河流、近岸水下扇、扇三角洲、深水浊积扇、三角洲、三角洲前缘滑塌浊积扇以及滨浅湖滩坝 ,岩石类型主要是砾岩、含砾砂岩、中粗砂岩及粉砂岩。不同成因类型的碎屑岩储集体成分成熟度和结构成熟度差异较大 ,三角洲河口坝及滨浅湖滩坝砂体成分成熟度和结构成熟度最高。不同成因类型储集体的物性特征不同 ,河流相、(扇 )三角洲前缘水下分流河道及河口坝砂体储集物性最好 ,其次为 (扇 )三角洲前缘席状砂及滨浅湖滩坝砂体 ,近岸水下扇和浊积扇砂体物性相对较差。图 4表 4参

The Paleogene in Dongying Sag developed different sedimentary types of petroclastic reservoir rocks at the different stages of basin evolution, forming depositional environments of alluvial fan, river, nearshore subaqueous fan, fan delta, deep water turbidite fan, delta, delta front slump turbidite fan, and bar shore shallow lake. The reservoir rocks consisted of conglomerate, pebbly sandstone, medium arenose sandstone, fine sandstone and siltstone. Different sedimentary types of reservoir rocks have the different componential and textural maturities, of which delta front mouth bar and bar shore shallow lake reservoir sands have the highest componential and textural maturities. The reservoir rocks deposited in fluvial environment, (fan) delta front subaqueous distributary channel and mouth bar have the most effective reservoir properties, (fan) delta front mat shipped and bar shore shallow lake sands are in the second, and nearshore subaqueous fan and turbidite fan sands have the poorest reservoir properties.