基于连续小波的地层品质因子计算方法

Calculation Method of Formation Quality Factor Based on Continuous Wavelet

连续小波是一种先进的时频分析方法,可以准确提取地震数据的时间和频率信息。利用连续小波时频分析方法,将地震数据分为多频率尺度数据,计算不同频率尺度数据的振幅随时间变化的指数衰减因子,再用回归分析方法计算指数衰减因子随频率变化的斜率,最后计算出地层品质因子。模型和实际垂直地震剖面、微测井以及地震数据应用表明,连续小波地层品质因子计算方法与谱比法和频移法相比,精度高、抗噪声能力强,适用于多种类型地震数据的地层品质因子计算。

Continuous wavelet is a kind of advanced time-frequency analysis method that can extract information about time and frequency of seismic data accurately. Using continuous wavelet time-frequency analysis method, seismic data can be decomposed into multi-frequency scale data, and the exponential decay factor for amplitude versus time in different frequency scale can be calculated, the slope of exponential decay factor versus frequency curve can be calculated by using regression analysis method and finally formation quality factor can be calculated. The applications of model, VSP, uphole survey and seismic data indicate that compared with the methods of conventional spectral ratio and frequency shifting, the calculation method of formation quality factor based on continuous wavelet is a kind of high-precision, high noise immunity method which can be used in formation quality factor calculation for various seismic data.