Automated full waveform seismic-to-well tying

Abstract

A novel way of treating seismic-to-well misties is presented, which allows for the fact that logs and seismic have been acquired at very different scales. Also the case where a well is offset from a 2D line is covered by this procedure. The scale gap is bridged by defining a log perturbation mechanism, whereby the logs are realistically modified, driven by a small parameter set only. These parameters are optimised by inverting the seismic gather for them. The modelling of the well synthetic traces for the various perturbation réalisations is a full waveform modelling technique that produces all internal multiple reflections and mode conversions over the target interval. In this way it will be more difficult to match seismic noise by adjusting the log perturbation parameters. A wavelet extraction procedure has been built into this procedure. The method is demonstrated on a public data-set and leads demonstrably to a better match and consequently to better scaling in the wavelets extracted. This is important in quantitative interpretation projects.