Velocity Inversion with an Iterative Normal Incidence Point (NIP) Wave Tomography with Model-Based Common Diffraction Surface (CDS) Stack

Abstract

Normal Incidence Point (NIP) wave tomography inversion has been recently developed to generate a velocity model using Common Reflection Surface (CRS) attributes, which is called the kinematic wavefield attribute. In this paper, we propose to use the model based Common Diffraction Surface (CDS) stack method attributes instead of data driven Common Reflection Surface attributes as an input data parameter. In this way, the effects of Normal wave on Normal Incidence Point wave calculation are removed. In the proposed method, the velocity model is updated iteratively by an interactive between Common Diffraction Surface attributes and the velocity model produced by Normal Incidence Point wave tomography inversion. We applied the proposed method on a 2D complex land data set in the northeast of Iran. The events in the Common Image Gathers (CIGs) become flat after migrating the pre stack data by using the obtained velocity. This is while the events on the same Common Image Gathers that are processed by the data driven Common Reflection Surface stake method are not well flatted. These results show a great capability of the proposed method to obtain the velocity model compared to the single step Normal Incidence Point wave tomography inversion with Common Reflection Surface attributes.