海相砂岩小层单元内部砂体精细地质研究——以塔中16油田巴楚组东河含砾砂岩段为例

Detailed Geologic Study of Internal Sandbody of Layer Units in Marine Sandstone:A Case Study of Donghe Pebbly Sandstone Sub-Member of Bachu Formation in Tazhong-16 Oilfield

塔中16油田含砾砂岩段为海相滨岸沉积,分为5个小层,为满足油藏高效开发的需要,须进行小层内部单砂体的精细刻画。采用在测井曲线上进行岩电标定识别,将单一临滨砂坝细分为砂坝内缘、砂坝主体、砂坝外缘3个部分,将单砂体的识别标志分为离岸水道分割式、侧向接触式和垂向叠置式3种类型。层内单砂体的分布特征通过剖面上平行、斜交和垂直海岸的3个方向以及平面上分5个小层的方式进行了精细描述。在此基础上将小层级别和小层内单砂体级别应用到油田实际生产中,小层级别针对直井利用层间差异封堵高含水层段,有效实现了稳油控水;单砂体级别针对水平井利用单砂体之间的渗流差异封堵高出水层段,有效缓解了水平井的快速水淹。

The pebbly sandstone sub-member in Tazhong-16 oilfield as marine coastal deposits is divided into five layers and has to make afine description of internal single sandbody in the layers for the need of efficient reservoir development. By means of rock electric calibra-tion and identification on the well logs,the single shoreface dam is classified as inner edge,main part and outer edge,and the single sand-body can be divided into such three types as offshore waterway split,lateral contact and vertical superimposition. The distributions of the in-ternal single sandbody are described in detail on the section in directions of parallel,oblique and perpendicular to the coastline and on theplane in five layers. The case study shows that the single layer level is suitable for blocking high water-cut intervals according to interlayerheterogeneity in view of vertical well,which can effectively realize the water-cut control and stable production; while single sandbody levelfavorable for blocking high water-cut intervals according to seepage difference between single sand bodies in view of horizontal,which caneffectively alleviate the quickly waterflooded problem.