Modelling Anisotropy for Improved Velocities, Synthetics and Well Ties

The construction of a new-work flow for deriving well ties from deviated well log data is comprised of three main stages. These are the building of an anisotropic model of the sub-surface; the verticalisation of well velocities measured in deviated wells; and the replacement of isotropic formulations for computing PP and PS reflectivities with anisotropic counterparts, which are then used in extracting wavelets from seismic data and in computing synthetic traces. The development of this work-flow is described, together with field data that underlines its strength in producing well-ties that provide a better fit with observed data than those produced using a conventional, isotropic work-flow.