杏树岗油田浅水三角洲储集层构型及剩余油分布特征

Reservoir Architecture and Remaining Oil Distribution in Shallow-Water Delta, Xingshugang Oilfield

目前,国内外针对浅水三角洲分流河道砂体的层次结构分析尚未形成完整的研究思路和方法。为此,选取杏树岗油田中部密井网区,利用地震、测井、岩心、X射线荧光光谱分析(XRF)及物性分析测试数据等资料,分级次对浅水三角洲分流河道砂体进行定量刻画。结果表明,研究区浅水三角洲砂体可分为8个构型级别。其中,五级构型单元单期分流河道类型多样,规模各异;各期分流河道间多发育稳定隔层,控制了整体的注水开发效果。各类四级构型单元单井及平面分布特征差异明显,剩余油饱和度相差较大。三级构型单元发育多期,界面多为不稳定的物性夹层,控制了三元复合驱替效率及垂向剩余油分布。通过储集层结构分级次解剖,为研究区浅水三角洲分流河道砂体精细刻画及老油区特高含水后期剩余油挖潜提供了依据。

At present there are no mature research thinking and methods for hierarchical architecture analysis on distributary channel sand bodies of shallow-water delta facies in China and abroad.Taking the close spacing area in the middle of Xingshugang oilfield as a case,combining the data of seismic,logging,core,XRF and physical property analysis and test,the paper quantitatively characterizes the distrib-utary channels of shallow-water delta facies hierarchically.The results show that 8 architectural levels are classified for the sand body of shallow-water delta facies in the study area.The single-period distributary channels in the 5th architectural elements are various and of dif-ferent sizes,and stable interlayers are mostly developed between the distributary channels formed in different periods,which controls the general effect of waterflood development.The distribution characteristics of the different types of the 4th architectural elements are signifi-cantly different and the remaining oil saturation are various greatly in single wells and in the plane.The 3rd architectural elements are de-veloped in different periods with the interface mostly being the stable physical interlayers,which controls the efficiency of ASP flooding and vertical distribution of remaining oil.The hierarchical analysis on the reservoir architecture can provide basis for fine characterization of shallow-water delta distributary channel sand body in the study area and potential tapping of remaining oil at extra-high water cut stages in mature oilfields.