J油田长2油藏单砂体接触模式及其对生产开发的影响

Single Sand Contact Model of Chang 2 Reservoir and Its Impact on Production and Development in J Oilfield

J油田长2油藏位于鄂尔多斯盆地中东部,主要为网状河流相沉积,长23至长21时期由于水动力逐渐变弱,河道变窄,河漫滩广泛发育。该区微相类型主要为河道、天然堤以及河漫滩沉积,河道为主要有利储集相带。结合盆地内延河剖面观察,并依靠岩心、测井资料识别,研究区单砂体垂向上接触模式主要有叠切、分离、叠置;同时依据不同沉积微相、测井形态、高程差异及井组注采响应等进行单砂体侧向识别,主要侧向接触模式为孤立式、对接式、侧切式3类。此外,根据井间生产动态研究及砂体横向对比的6个原则(高程差异、厚度差异、形态差异、幅度差异、韵律差异、生产动态差异),刻画不同沉积期单砂体侧向与垂向接触关系及对产能的影响,为后续开发调整提供了依据。

The Chang 2 reservoir in J oilfield is located in the middle east of Ordos Basin.It is a typical reservoir of fluvial facies with braided river sedimentation.During the Chang 23 subage to Chang 21,because of weakening of hydrodynamic force,the river channel becomes narrow and the floodplains develop extensively.The main types of micro-facies in this area are channel,natural levee and floodplain deposits,and channel is the main favorable reservoir facies.Based on the observation of lithology profiles in YanHe river and the identification of core observation and logging data,the vertical patterns of individual sand-body are mainly 3 types of contact modes with superimposed-cut,separated and superimposed.At the same time,the lateral identification is carried out according to different sedimentary micro-facies,logging data and elevation difference,there are 3 contact modes of isolated,butt and side cut type.In addition,according to the production dynamics and six principles lateral contrast of sand bodies(elevation difference,thickness difference,shape difference,amplitude difference,rhythm difference and production performance difference),the relationship between lateral and vertical contact of single sand body in different sedimentary periods and its influence on productivity are described,which provides a basis for subsequent development and adjustment.