小波分频倾角相干在复杂断裂解释中的应用

地震相干属性为断裂解释提供了有力的技术手段,而复杂断裂带地区的地震相干体的解释面临两个主要问题:一是受分辨率的限制,不同级次的断裂无法区分,断裂主次关系不清;二是地层产状对相干属性的计算产生背景噪声干扰。因此,本文提出利用具有多分辨率分析能力的小波变换技术进行地震数据的分频重构,在不同频率的窄带地震数据基础上计算相干属性,并与倾角约束相干技术相结合,以解决复杂断裂带地区断层解释难题。将该方法应用于具有走滑压扭作用背景、以复杂断裂为特征的渤海辽东湾三维地震资料解释。结果表明:小波分频倾角相干技术能够有效地抑制地层产状引起的背景噪声,对复杂断裂体系进行多尺度分析,更有利于断裂的精细解释和断裂系统的整体研究,证明了该方法的有效性和实用价值。

Dip-steering similarity based on wavelet decomposition in complex fault interpretation

Seismic similarity provides an effective technical means for faults interpretation. However, seismic similarity in complex fault zone faces two major problems. First, relationships between primary and secondary faults are ambiguous and fault grades and scales cannot be distinguished due to resolution limit. Second, dip strata create serious background noise to seismic similarity calculation. Therefore, we propose in this paper a new approach for dip-steering similarity. We use multi-resolution and multi-scale wavelet analysis for seismic data decomposition and reconstruction. First we divide raw seismic data into different narrowband, and then calculate dip constraint similarity on this basis to solve complex faults interpretation problems. The approach is applied to a 3D seismic in Liaodong Bay, which is characterized by complex faults and fractures with strike-slip stress background. The results show that the proposed approach can effectively suppress the background noise caused by dip formations, and provide a powerful tool for complex fault interpretation.