方向可控金字塔的地质体边界识别方法及在砂砾岩油藏中的应用

Application of the directionally steerable pyramid method to identify geological boundaries in a conglomerate sand reservoir

快速沉积的砂砾岩单元复杂非均质性导致了储层不连通,进而形成剩余油,影响了开发效果,这是油田生产开发中后期亟待解决的问题。砂砾岩沉积单元的地震响应差异小,需要采用不同于常规方法的单元边界检测方法,为此提出了利用方向可控金字塔方法实现单元体边界检测。首先,将地震属性图像作为输入信号,通过构建地震属性图像金字塔对各个尺度的地震属性图像进行多方向分解;然后对不同方向的地震数据加入方向滤波估计,得到最优方向的结果;最后将各尺度的地震属性图像重构得到最终的地震属性图像。采用方向可控金字塔的地质体边界识别方法将地震属性分解为多尺度、多方向的特征分量,可以增强表征沉积地质体的横向分布特征,该方法可以挖掘地震属性中隐蔽的沉积地质体分布特征,并利用沉积规律在各个分量的显示度对其进行重新组合,这对准确刻画井间沉积地质体边界起到关键作用。将该方法应用于春风油田p609区块沙湾组地层的边界识别,应用结果表明,p609区块西部为扇三角洲沉积,由多个北西西向地质体组成,东部14井区为辫状河三角洲沉积,为北北东向地质体,利用方向可控金字塔的地质体边界识别方法处理后的地震属性和位于同一组地质体的累产油量具有高度的相关性。

The strong heterogeneity among the flow units in fast-deposited conglomerate sand is the main factor affecting the production performance and the amount of non-extracted oil.It is also a critical issue for performance improvement during the middle and mature periods of oilfield production and development.Owing to the subtle differences in the seismic response of glutenite sedimentary units,a new method for boundary detection should be developed.To this aim,a steerable pyramid filtering approach is proposed,which takes an attribute image as an input and decomposes the seismic attributes into multiscale and multidirectional components.After decomposition,the components were investigated to look for possible boundaries.Then,the processing results were reconstructed using the components at all scales.The lateral distribution characteristics of the sedimentary geological objects were enhanced through filtering and reconstruction.An application to the Shawan Formation in the p609 block demonstrated that the proposed method could effectively enhance the boundaries of the geological bodies in seismic images by combining different components based on sedimentary features.This played a key role in accurately delineating the boundaries of such bodies between wells.The western part of block p609 is a deltaic deposition system composed of several NWW-trending geological bodies,while the eastern 14 well area is a deltaic braided channel system,and is composed of NNE-trending geological bodies.A high correlation was observed between the accumulated oil yield and the seismic attributes processed by the direction steerable pyramid method for the same geological object.