Deblending in common receiver and common angle gathers

Ziguang Su, Daniel O. Trad

In certain seismic acquisition scenarios, such as ocean bottom node (OBN) surveys, there are more sources than receivers. This imbalance can be an issue since the efficiency of conventional deblending and migration algorithms in common shot gathers (CSG) is related to the number of available traces (fold) in this gather. Therefore, we need to develop new deblending and migration algorithms that process data in domains other than CSG. Preferably, domains that have higher fold numbers than the CSG for these acquisition scenarios. Due to reciprocity, common receiver gathers (CRG) is equivalent to common shot gathers. Therefore, migration in the CRG domain is very similar to conventional migration in the CSG domain. Moreover, in the OBN case, reverse time migration (RTM) in the CRG domain saves significant memory and computational time compared to the CSG domain since the number of receivers is much smaller than the sources. Furthermore, blending interferences have an incoherence structure in CRG due to random time delays between sources, which significantly improves deblending performance. This report investigates the efficiency of RTM and least-square RTM in the CRG domain as a deblending tool. Additionally, we investigate the suitability of other domains such as common angle gather (CAG), as another domain for deblending using RTM.