The determination of the constant phase of seismic wavelet using automatic seismic-well tying

Abstract

ABSTRACTSeismic wavelet estimation is the bedrock of seismic-well tying and seismic inversion but remains a challenge. Huge amounts of effort have been expended on seismic wavelet estimation and determining the amplitude and phase spectrum is a time-consuming task. In this article, we develop a workflow to determine automatically the constant phase of an estimated wavelet. This workflow begins with statistical wavelet estimation and seismic-well tying. We then extract a new seismic wavelet with a constant phase by using the well and seismic data together. To obtain the best phase for the extracted wavelet using well and seismic data, we rotate the phase of the wavelet by a user-defined increment and perform automatic seismic-well tying for each phase-rotated wavelet. The phase that reaches the maximum correlation coefficient between the synthetic and seismic data is regarded as the best phase for wavelets in each iteration. We next update the time–depth relation using the best seismic-well tie (the maximum correlation coefficient). We repeat the wavelet estimation using well and seismic data, phase rotation, automatic seismic-well tying and time–depth updating until the difference between wavelets, and time–depth relationships, in the current and previous iterations is below a user-defined threshold.