摘要
针对正交偶极声波测井检测地层各向异性和确定构造应力中频散分析的必要性,本文利用合成和实测阵列声波测井数据分析和比较了三种频散分析方法:Prony方法、同态处理方法和谱域加权相似法.这三种频率域处理方法提取得到了合理的、一致的慢度结果.谱域加权相似法只能用于每一频率下单一波模式的慢度估计;同态处理方法还可以同时估计单一波模式的衰减、幅度和初相位;利用SVD_TLS算法确定波模式的阶数后,Prony方法可以有效地估计每一频率下多个模式的上述参数.另外,通过谱域加权相似法对正交偶极声波测井阵列数据进行频散分析,观察到了弯曲波频散曲线的交叉现象,从而确定出了对应地层所受最大水平主应力的方向.
As a dispersion analysis is essential to the estimation of anisotropy and in situ stress of formation by cross-dipole logs, we have carried out dispersion analysis on synthetic and field array sonic logs with three methods, namely, the Prony＇ s method, homomorphic processing, and weighted spectral semblance. These frequency domain processing methods yield reasonable and consistent slowness estimations. Weighted spectral semblance is only able to give the slowness estimation for a single mode at each frequency. While homomorphic processing can also be used to calculate attenuation, amplitude and phase of one mode simultaneously. By introducing the SVD-TLS algorithm to determine the order of the wave modes, the Prony＇ s method can be utilized to effectively estimate all the above parameters for more than one mode at all frequencies. In this study, we have also observed the crossover of flexural wave dispersion curves calculated by the weighted spectral semblance processing of the cross-dipole logs and determined subsequently the direction of the maximum horizontal formation stress of the surrounding formation.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第6期1449-1459,共11页
Chinese Journal of Geophysics
基金
中国博士后科学基金项目(2004036104)资助
关键词
频散分析
PRONY方法
同态处理方法
谱域加权相似法
Dispersion analysis, Prony＇s method, Homomorphic processing, Weighted spectral semblance
