VSP Kirchhoff Migration with Structure Constraint

Prestack Kirchhoff depth migration is commonly used in borehole seismic imaging. Its application in this scenario is limited by insufficient coverage of the data acquisition configuration. In this paper, we combine the existing VSP Kirchhoff migration/imaging technique with the structure dip information from a newly developed structure tensor analysis, resulting in a new workflow for the VSP migration/imaging. The workflow allows us to better image both the structures in the vicinity of borehole and the far-field dipping events away from borehole. We tested the workflow with the HESS salt model and confirmed the results with the reverse-time migration (RTM). The results demonstrate that, even with the conventional Kirchhoff migration, combining structure dip information not only reduces ambiguities of the imaging result but also allows for imaging dip structures (e.g., fault) in the far borehole region. The proposed method with structure constraint provides a useful extension of existing VSP imaging capabilities.