Enhanced 4D Imaging in West Africa Using High-resolution Tomography and Q-imaging

A high-resolution tomography and imaging approach is used to enhance the 3D and 4D responses of a complex production field, West Africa. The approach relies upon building a high-resolution anisotropic vertical transverse isotropic (VTI) earth model including anisotropic velocity and 1/Q components and applying amplitude and phase Q-compensation within Kirchhoff prestack depth migration. Velocity and absorption effects associated with overburden heterogeneities are nicely mitigated, leading to enhanced amplitudes and resolution in the prestack gathers and 3D/4D images.