高北斜坡带沙三沉积期沉积环境及储层特征研究

Sedimentary environment and reservoir characteristics during depositional stage of Es_3 in Gaobei ramp region

盆地沉积环境研究对于预测储层分布及分析储层特征具有重要意义。在岩石学、沉积构造、古生物学、沉积序列及测井相研究的基础上,对冀东油田高北斜坡带沙三段（Es_3）沉积环境特征进行研究。结果表明：Es3沉积期为扇三角洲—滨浅湖沉积环境;沉积序列为Es3^3沉积期湖盆萎缩→扇三角洲发育、Es3~2沉积期湖盆扩张→扇三角洲萎缩、Es3~1沉积期湖盆再度萎缩→扇三角洲发育;高尚堡油田北东向中央构造带的隆起过程使得研究区存在2个相对独立的沉积分区。通过探讨沉积环境对储层发育的控制作用认为：扇三角洲水下分流河道和河口坝是形成储层砂体的主要沉积体;储层砂体的分布和发育规模均受到扇三角洲发育特征的控制;沉积环境变化导致岩性在横向和纵向上有所变化,并引起储层非均质性增强。

It is important for the prediction of effective reservoir distribution and analysis of reservoir characteristics to study the sedimentary environment of basin. Based on the study about petrology, sedimentary structure, palaeobiology, sedimentary sequence and electrofacies, the sedimentary environment of the third member of Shahejie Formation （Es3） in Gaobei ramp region of Jidong Oilfield was studied. It is revealed that the sedimentary environment of E s3 is fan delta-shallow lake facies. The evolutionary process is represent that lake was shrinking and fan delta was growing at E s33 period, lake was growing and fan delta was shrinking at E s32 period, and lake was shrink again, fan delta was growing again at E s31 period. There are two relatively independent sedimentary zones in the study area, which are caused by the uplift of central tectonic zone with NE trend in Gaoshangpu Oilfield. Meanwhile, the control role of sedimentary environment on reservoir development was discussed. It is considered that fan delta underwater distributary channel and mouth bar are the main lithosomic bodies for reservoir sand body. The distribution and development scale of reservoir sand body are controlled by the characters of fan delta development. The lithological changes on the horizontal and vertical are caused by the change of sedimentary environment. And it is the important cause of strong reservoir heterogeneity.