三维边缘保持滤波方法在海上地震数据噪声压制中的应用研究——以东海某凹陷为例

The application of 3D edge-preserving de-noising methods based on structure oriented in a complex faults block:A case study of C oilfield in East China Sea

东海C区块具有复杂断块发育、地层非均质性强、储层连通性复杂等特点,同时受采集等因素的影响,地震资料随机噪声较为严重,给后续的勘探开发工作带来极大挑战。为此本文提出将改进的F-X滤波和各向异性扩散滤波技术相结合的三维边缘保持滤波方法。该方法通过结构张量估计得到目标地层的倾角和方位角,在倾角和方位角信息约束下提取目标点位置处的滤波窗口,在滤波窗口内采用自适应F-X滤波,从而实现随机噪声的压制,增强有效反射信息的连续性、保护断层等不连续地质体的边缘信息的目的。三维模拟数据和实际地震数据测试表明,与常规F-X滤波方法以及各向异性扩散滤波方法相比,新方法在提高数据体信噪比的同时,能有效保护断层等边缘信息的反射信号,增强地震剖面中弯曲、倾斜同相轴的连续性,在时间切片中较好地展示地质体边缘信息的连续性。

Block C of the East China Sea has the characteristics of complex fault block development, strong stratigraphic heterogeneity, and complex reservoir connectivity.Affected by acquisition and other factors, the random noise of seismic data is relatively serious, which brings great challenges to subsequent exploration and development work.To eliminate random noise effectively and keep the structure information of seismic reflection at the same time, this paper proposes a de-noising method by combining anisotropic diffusion filter technique and F-X edge-preserving filter method.The new method obtains the dip and azimuth of the target formation by gradient structure tensor, extracts the filter window at the target point under the constraints of the dip and azimuth information, and uses adaptive F-X filtering in the filter window to suppress random noise, finally reaching the goals of improving the continuity of seismic reflection in complex fault zone and enhancing the coherence of reflection event and highlighting the edges.The results of 3 D modeling and application in real 3 D data indicate that the new method has effectively smoothed the reflection events without blurring relevant details of faults and discontinuities on seismic sections. Compared with conventional de-noising method, the new method can improve signal-to-noise ratio and protect seismic reflection and structural information.Meanwhile, the continuity of the edge information of the geological body is better displayed in the time slice.