扇三角洲厚储层构型解剖及在高含水期剩余油挖潜中的应用——以珠江口盆地文昌B油田为例

Architecture analysis of fan delta thick reservoir and its application in potential tapping of remaining oil at high water cut stage:Taking the Wenchang B oilfield in Pearl River Mouth Basin as an example

以珠江口盆地文昌B油田珠海组二段一油组扇三角洲储层为例,采用井震结合划分朵叶体、沉积旋回划分复合砂体、多维信息定单砂体的逐级细分方法对储层构型进行了剖析,建立了扇三角洲储层构型模式,并应用于高含水期剩余油分布研究,结果表明:目的层由三期扇三角洲朵叶体组成,每期朵叶体分3~4个复合砂体,复合砂体内部的单砂体宽度100~450m,厚度1.5~6m,宽厚比为40~80;剩余油分布模式分为不渗透构型界面控油模式和差异渗流构型单元控油模式,开发调整重点为不同期次水道叠置区以及受四级构型界面遮挡的剩余油富集区;现场部署调整井B3S1井,日产油276m^3/d,同时指导B5/B6井下返补孔,累增油15.05×10^4m^3,提高采收率1.5个百分点。

By taking the fan delta reservoir of the first oil group in the second member of Zhuhai Formation in Wenchang B oilfield as an example,the reservoir architecture has been analyzed by adopting the step-wise subdividing methods,such as the well-seismic combination lobes-division,the sedimentary cycle composite sand bodies division and the multidimensional information single sand body determination,and then the fan delta reservoir architecture modes have been established,which can be applied in the study of remaining oil distribution at high water cut stage.The results show that the target layer is composed of three-stage fan delta lobes.The lobe in each stage can be divided into 3~4 composite sand bodies,the single sand body inside the composite sand body is 100~450 m in width and 1.5~6 m in thickness,with a width-to-thickness ratio of 40~80.The remaining oil distribution modes can be divided into an impermeable architecture interface oil control mode and a differential permeation unit oil control mode,and the key development targets are adjusted to be the overlapping areas of channels in different stage and the remaining oil enrichment area blocked by the four-level architecture interface.The adjustment well B3 S1 is deployed on site,and a pure oil production of 276 m^3/d per day is observed.At the same time,the downward supplementary perforation is carried out in well B5&B6 under out guidance,which achieves an accumulate oil increment of 15.05×10^4 m^3 and a recovery factor increase of 1.5%.