The estimation of the Q factor of rocks by seismic surveys is a powerful tool for reservoir characterization, as it helps detecting possible fractures and saturating fluids. Seismic tomography allows building 3D macro‐models for the Q factor, using methods as the spectral ratio and the frequency shift. Both these algorithms require windowing the seismic signal accurately in the time domain; however, this process can hardly follow the continuous variations of the wavelet length as a function of offset and propagation effects, and it is biased by the interpreter choice. In this paper, we highlight some drawback of signal windowing in the frequency‐shift method, and introduce a tomographic approach to estimate the Q factor using the complex attributes of the seismic trace. We show that such approach is particularly needed when the dispersion is broadening the waveforms of signals with a long wave‐path. Our method still requires an interpretative event picking, but no other parameters as the time window length and its possible smoothing options. We validate the new method with synthetic and real data examples, involving the joint tomographic inversion of direct and reflected signals. We show that a calibration of the frequency‐shift method is needed to improve the estimation of the absolute Q factor, otherwise only relative contrasts are obtained.

中文翻译：

---

通过瞬时频率进行无窗Q因子层析成像

通过地震勘探估算岩石的Q值是表征储层的有力工具，因为它有助于检测可能的裂缝和饱和流体。地震层析成像可以使用频谱比和频移等方法为Q因子建立3D宏模型。这两种算法都需要在时域中准确地对地震信号进行加窗处理。但是，这个过程几乎不能跟随小波长度的连续变化，这是偏移和传播效应的函数，并且它受解释器选择的影响。在本文中，我们重点介绍了频移方法中信号窗口化的一些缺点，并介绍了一种层析成像方法，利用地震道的复杂属性来估计Q因子。我们表明，当色散扩展具有长波路径的信号的波形时，这种方法特别有用。我们的方法仍然需要解释性事件选择，但不需要其他参数，例如时间窗口长度及其可能的平滑选项。我们用合成的和真实的数据示例验证了新方法，该示例涉及直接和反射信号的联合层析成像反演。我们表明，需要使用频移方法的校准来改善对绝对Q因子的估计，否则只能获得相对对比度。涉及直接和反射信号的联合层析成像反演。我们表明，需要使用频移方法的校准来改善对绝对Q因子的估计，否则只能获得相对对比度。涉及直接和反射信号的联合层析成像反演。我们表明，需要使用频移方法的校准来改善对绝对Q因子的估计，否则只能获得相对对比度。