Improved Statics Estimation through Refraction Tomography and Surface Waves - Data Example Onshore Abu Dhabi

Abstract

The shallow subsurface can be extremely complex and challenging from a geological and geophysical point of view. Near-surface perturbations impact the imaging of the deeper events and therefore have to be corrected in the seismic reflection information. It is also known that solving the near surface is an important part of any depth imaging velocity modeling. Usually we use refracted waves for P-wave velocity model estimation. Refraction data provide the information about the deeper subsurface and gives directly Vp velocity. In areas with complex near surface estimation of Vp on refracted energy can be challenging: velocity inversions and hidden layers can produce ambiguity in the refraction solution. The near-surface model obtained through surface wave inversion gives geometric information about the near-surface layers, geology, velocity and attenuation distribution down to the investigation depth. Because the propagation properties of the surface waves are directly depend on elastic properties of the near surface, the dispersion of surface waves is the physical property used for its characterization. Presented example of the simultaneous joint inversion successfully shows that resulting compressional and shear depth velocity models provide significant improvement to support refraction statics and shallow velocity model building.