焉耆盆地宝北区块三工河组沉积微相与产能关系

The Relationship of Depositional Microfacies to Petroleum Productivity of Sangonghe Formation in Baobei District of Yanqi Basin.

宝浪油田宝北区块下侏罗统三工河组为浅水缓坡型粗粒辫状河三角洲-湖泊沉积体系。主要发育水下分流河道、水下分流河道间、决口水道(扇)、漫岸溢流沉积、滨湖沼泽沉积五个微相。水下分流河道砂体占研究区储集层的90%以上,根据砂体的岩石相组合、冲刷程度、水流能量大小的变化规律,又可分为三种基本类型:充填河道、废弃河道、进积河道,储集层物性以废弃河道为最好,单井油气产能亦最高,充填河道次之,进积河道和决口水道(扇)则相对较差。油气产能受储集层的沉积微相类型、微相位置、微相展布控制。

Sangonghe formation(J 1 s)in Baobei district of Baolang oilfield,Yanqi basin,is a braided river delta-la-custrine depositional system of shallow gentle slope with coarse grains.It has five microfacies developed,including un-derwater distributary channel,underwater distributary interchannel,crevasse channel(fan),overband flood deposit and lakeshore swamp deposit.The sand body of underwater distributary channel accounts for over90percent of reservoir in study area,which can be classified into filled channel,abandoned channel and progradational channel,based on the sand body's petrofacies assemblage,scour extent,variation of current energy size.Of which the petrophysics of aban-doned channel is the best,the well productivity is the highest too;the filled channel is secondary;progradational chan-nel and crevasse channel(fan)are relatively poor.The study shows that the oil-gas productivity is controlled by types lo-cations and distribution of depositional microfacies in Sangonghe reservoir.