Integrated Anisotropic Model Building and Imaging Using a Hybrid Cable DAS VSP

Abstract

Summary Sonic anisotropy is integrated with multi-offset hybrid cable DAS VSP data to build and calibrate VTI models with different scales. Microseismic, seismic reflection and imaging scale models are produced. The initial VTI model from sonic anisotropy is cross-validated against microseismic data; lower frequency seismic reflection and imaging models are calibrated using travel time inversion of direct P times from the hybrid multi-offset VSP data set. The reflection model is used for simulation and prestack seismic well-tie; the imaging model is used for DAS VSP migration. The models aid in quantitative interpretation and provide a starting point for a future depth imaging project. DAS simulation uses dynamic ray theory to compute axial strain and includes wavenumber system response filters. Simulations are shown for offset VSP and microseismic. The simulation theory informs amplitude factors for true amplitude DAS VSP imaging.