Time-Lapse Multiple Removal Technique to Improve 4D Interpretation in the Gas Cloud Region at Valhall

H018 Time-Lapse Multiple Removal Technique to Improve 4D Interpretation in the Gas Cloud Region at Valhall P.J. Hatchell* (Shell International Exploration & Production BV) & P.B. Wills (Shell International Exploration & Production BV) SUMMARY Since late 2003 more than six seismic surveys have been acquired for the Valhall Life-of-Field-Seismic (LOFS) project an OBC system installed to provide frequent and high-resolution snapshots of the field production. Excellent quality time-lapse data are acquired on the flanks of the field but in the crest shallow gas severely attenuates the PP seismic data. An examination of the seismic data near the reservoir zone shows