Improving Acquisition Efficiency by Managing Seismic Interference - Snorre 4D Survey 2012

A seismic acquisition on the Snorre field has been conducted in summer 2012. The Snorre field is in a very busy area of the North Sea including fishing activity, production activity and concurrent seismic acquisition. Due to tight time constrains, special care was given to the treatment of the seismic interference in order to avoid timeshare as much as possible. Ahead of the acquisition, the onboard processing sequence and the onboard QC attributes have been revisited in order to handle the seismic interference and its QC has good and as quickly as possible. During the acquisition, the onboard processing team produced QC displays of the seismic interference removal as soon as possible and made them available for remote QC. Acceptance decisions were made based on seismic interference removal QC displays, RMS displays, noise displays and near trace displays. 4D QC was also produced on a regular basis. The cooperation between the onboard processing, client representative, onshore processing and client QC made it possible to have a very short turnaround time and a very efficient acquisition. Out of the 49 sequences affected by seismic interference, 5 ended up being reshot. The survey was complete 14 days ahead of schedule.