Comparisons of Model Independent Two-Parameter Moveout Formulas for the CMP Gather

Abstract

We investigate different moveout equations used to describe reflection events in a CMP gather. For homogeneous models with flat and dipping reflectors the reflection event is hyperbolic and entirely defined by the well-known one-parametric normal moveout equation. To handle more complex reflection events several two-parametric moveout equations have been proposed. Although each traveltime equation has been derived for a specific class of models, our objective is to compare some of these moveout equations for a large range of different models. In addition to their ability to fit a reflection event from an arbitrary model we are interested in the accuracy of the parameter estimation. For our tests we implemented a simultaneous parameter search to estimate the parameters from the data without using any a priori information of the model. Our tests show that in cases where the standard hyperbola only accounts for near offset reflections, the investigated formulas are able to approximate a reflection event over a larger range of offsets. However, the considered formulas are not similar, i.e. the equations show different behavior in order to treat deviations from the standard hyperbola.