Integrated 4D Processing and Inversion Workflow Using Multi-well Wavelet Extraction

We present an integrated processing and inversion workflow, applied to a major 4D project in the Danish North Sea, covering 9 fields with up to 4 seismic vintages. Intermediate processing QC volumes are used for multi-well wavelet extraction and 4D inversion. The results of these intermediate inversions enable us to feed observations back into the processing loop, and can also be used at early stages by the reservoir management teams to influence ongoing workover and well planning activities. The key to this workflow is being able to perform the wavelet extractions and 4D inversions in a timely manner, which requires dedicated proprietary software. For example, one of the larger 4D inversions, covering 4 fields and using 19 wells for wavelet extraction, took 5 days to complete. We will present results from wavelet extraction studies and show examples where up to 3 intermediate QC outputs were inverted before the final processing. We emphasise the value of an integrated project team working closely with assets and external contractors.