Abstract

The Mangala field, located in Barmer Basin, Rajasthan, India is covered by 3D seismic data from two vintages. The first survey, the NR3D was acquired and processed during 2005 and again reprocessed in 2010. Another high-density 3D seismic survey, the HD3D, was acquired in 2007 with a different orientation and processed to support field development. Vertical and lateral resolution of the HD3D data is superior whereas image quality of the NR3D data is significantly better along the main trapping fault. These datasets have amplitude and phase spectrum mismatches due to different acquisition and processing parameters which complicate their simultaneous interpretation. This abstract describes the workflow to merge these datasets, focusing on minimizing attribute mismatches. This modified 4D workflow involves regridding of NR3D data to reconcile orientation differences, applying a global phase and time matching to reconcile the time and phase differences, applying a shaping filter for bandwidth and energy matching and then merging the two datasets. This post-stack merging process preserved the better quality of NR3D data at the crestal part of the field, and good quality of HD3D data in the structural flank areas.