| Popis: |
Prior 4D studies in the Lena field (Mississippi Canyon 281) using 1983 and 1995 legacy seismic data have been reported by Eastwood et al. (1998, 1999). As one of the first steps in a multi-disciplinary 4D study, the time lapse analyses reported in those studies used the migrated datasets as originally processed, applying post-stack cross equalization and residual migration techniques. In a parallel effort, the seismic datasets underwent reprocessing from field tapes. Although these datasets presented many unique processing challenges, full reprocessing provides superior repeatability and resolution relative to legacy cross equalization and residual migration. The most significant improvements are obtained through the consistent application of DMO and post stack time migration. While the previously reported methodology is sufficient only for the B80 reservoir, which dips gently and is spatially separated from the salt flank, the new fully reprocessed data has improved imaging so that time-lapse analysis can be performed for more steeply dipping reservoirs adjacent to the salt flank. |
