Seismic Attenuation Parameter Estimation Based on Improved GLCT

When seismic waves propagate through hydrocarbon reservoirs, there is a significant attenuation of high-frequency energy. The quality factor Q is usually treated as a sensitive parameter indicating oil and gas reservoirs, but extracting seismic attenuation parameters using the conventional time-frequency domain methods often yields unsatisfactory results. In order to improve the accuracy of Q estimation, we propose a new method for calculating seismic parameters. We first introduce a Gaussian window into the general linear chirplet transform (GLCT) based on dominant frequency weight, which is now used in the W-transform (WT). This modification enables the improved GLCT (IGLCT) to adjust its time-frequency resolution according to the changes at the seismic dominant frequency, thereby enhancing the time resolution of conventional GLCT. Subsequently, based on the characteristics of high-frequency energy attenuation anomalies in seismic records and in combination with the Teager-Kaiser energy operator (TKEO), then the effective estimation of seismic attenuation parameters is achieved. This method can obtain a higher resolution time-frequency spectrum compared to conventional time-frequency analysis (TFA) methods. In addition, the TKEO used in this technique has significant instantaneous features, which can be used to accurately estimate the energy of monofrequency signals. Finally, seismic attenuation parameters are calculated based on the quantified definition of the quality factor Q and the relative energy attenuation within the given time window. Theoretical model testing and actual data processing indicate that the proposed method for estimating seismic attenuation parameters has the capability for identifying the thin layers and can effectively predict the hydrocarbon reservoirs.