POCS-based geophysical constraints in multi-parameter Full Wavefield Inversion

Simultaneous updating of several parameters in Full Wavefield Inversion (FWI) can lead to poor convergence and unsatisfactory results due to cross-talk among various inversion parameters. Even more dangerously, certain parameter combinations may correspond to physically unrealizable models, leading to instabilities in forward simulations. Both types of problems can be addressed by imposing appropriate rock-physics-based constraints. We demonstrate that Projection Onto Convex Sets (POCS) can be incorporated into multi-parameter FWI for the purpose of imposing multiple types of geophysical constraints and ensuring that forward simulations remain stable. Performance of the proposed method is illustrated with a field data example.