Valhall Microseismicity Revisited – Relocated Sources, Seismic Multiplets and S-Wave Splitting

A038 Valhall Microseismicity Revisited – Relocated Sources Seismic Multiplets and S-Wave Splitting K. De Meersman (CGG Veritas) J.M. Kendall* (University of Bristol) & M. van der Baan (University of Leeds) SUMMARY We relocate 303 microseismic events that were recorded in the North Sea Valhall oilfield in 1998. A semiautomated re-picking of P-wave and S-wave arrival times and array based P-wave polarisation analysis improves the accuracy of the locations. Our multiplet analysis identifies 40 multiplet groups that include 208 events. Using cross correlation we then further increase the relative location accuracy between multiplet members. The P-waveform similarities between the different multiplets