Repeatability Enhancement in Deepwater Permanent Installations

C-03 REPEATABILITY ENHANCEMENT IN DEEPWATER PERMANENT INSTALLATIONS Summary 1 Seawater velocity variations can have a significant impact on the repeatability of frequently acquired time-lapse seismic data. Here this effect is assessed by processing modelled data based on a real hydrocarbon reservoir in the West of Shetlands. The repeatability metrics calculated for synthetic seabed data perturbed by realistic seawater velocity variations indicate poor seismic repeatability. The data are then corrected in the shot domain according to a new method which removes the dynamic traveltime differences for each trace. After correction the distortions caused by the water changes are virtually eliminated. We