Monitoring Overburden Layer Changes and Fault Movements from Time-Lapse Seismic Data

H019 Monitoring Overburden Layer Changes and Fault Movements from Time-Lapse Seismic Data T. Røste* (Statoil ASA) M. Landrø (NTNU) & P. Hatchell (Shell) SUMMARY Overburden changes and fault movements are investigated on prestack time-lapse seismic ocean bottom (OBC) data from the Valhall Field. Based on a method developed by Røste et al. (2005) we estimate the dilation factor alpha which is the relative velocity change divided by the relative thickness change within a given layer. The high quality and good repeatability of the OBC data enables us to estimate alpha with a reasonable accuracy for alpha-values between 0 and -5.