地震反Q滤波应用于碳酸盐岩储层特征描述

Seismic inverse Q filtering for carbonate reservoir characterization

塔里木盆地塔河地区的奥陶系碳酸盐岩储层埋藏深,其深度超过5000m,储集体类型以裂缝、缝洞为主,储层的纵向和横向上都具有极强的非均质性.这些特点导致反射地震数据的信噪比低、分辨率低,从而使得碳酸盐岩储层特征描述的难度增大.针对这些问题,本文运用稳定化反Q滤波方法对塔河地区的三维地震数据进行提高分辨率处理,同步实现地震振幅补偿和子波相位校正.处理结果与原始地震数据进行地震剖面面貌、储层内幕信息、断裂缝洞刻画等方面的直接对比,一方面展示反Q滤波方法在提高分辨率、提高弱反射能量、以及增强反射同相轴的空间连续性等方面的优势,同时展示稳定化反Q滤波方法能够提高对奥陶系碳酸盐岩缝洞储集体的特征描述精度.

The Ordovician carbonate reservoir in Tahe oilfield, Tarim basin, is buried very deep with a depth being larger than 5000 m. The reservoir is featured by fracture-vuggies, and the formation has extremely strong heterogeneity in both the vertical and horizontal direction.These features lead to low signal-to-noise ratio and low resolution of the seismic reflection data, and in turn to the difficulty in characterization of carbonate reservoirs.Aiming at these problems, here we use a stabilized inverse-Q filter to process the three-dimensional （3D） seismic data in Tahe oilfield, conducting seismic amplitude compensation and waveform phase correction, simultaneously.Comparing the inverse-Q filtered result directly with the raw seismic data in terms of seismic profiling, interior information within the reservoir, characterization of faults and fracture-vuggies, we demonstrate the advantages of stabilized inverse-Q filtering in enhancing seismic resolution, strengthening weak signals, and improving lateral continunity of reflections, and reveal that this method can improve the accuracy of fracture-vuggy characterization in the Ordovician carbonate reservoirs.