Introduction

Velocity estimation is a very important and difficult step in the seismic imaging problem. Because of the non-uniqueness in the velocity estimation, understanding the relationship between velocity models and seismic attributes could contribute insight into the seismic imaging problem. Therefore, the objective of this study is to understand the sensitivity of seismic attribute response to velocity uncertainty.

In recent years, there has been an enthusiastic use of seismic attributes to predict reservoir properties. Many new attributes have been designed Chen and Sidney (1997) in the hope of finding any relationship between attributes and the reservoir properties that can be used in prediction. However, although the ability to generate numerous seismic attributes has improved, physical relationships between attributes and reservoir properties are not always well understood. In order to decide which attributes to use for this research, we have focused our attention on some "better understood" attributes, in other words, those that can be related to physical parameters, such as amplitude versus offset (AVO), reflectivity, acoustic impedance, compressional-wave velocity (V_p), and shear-wave velocity (V_s). For this particular study, we have chosen AVO-related attributes because of the physical relation between the variation of reflection/transmission coefficients and incident angle and elastic rock parameters like V_p, V_s, and density $\rho$ Castagna et al. (1993).