Signature-related time shift adjustment of direct wave arrival times for correction of OBS data

SUMMARY

Ocean bottom seismics (OBS) is crucial for seismic imaging and reservoir monitoring but faces challenges due to positioning errors, water velocity variations, and clock drift. These issues impact data accuracy and require correction methods very early in the data processing sequence, when de-signatured seismic traces are not available.

This study introduces a method to correct picked direct wave arrival times of raw seismic data, by addressing source signature directional effects. The approach involves two steps: estimating a bulk time shift and calculating angle-dependent corrections from the data itself.

The method was tested on synthetic and real data from the Gorgon OBN survey in Western Australia. Results show that applying these corrections improves the accuracy by enhancing model fitting