TN666 : NIP tomography velocity inversion with considering VTI anisotropy
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2016
Authors:
Farid Mahmoud Pashazadeh [Author], Mehrdad Soleimani Monfared[Supervisor], Amin Roshandel Kahoo[Supervisor]
Abstarct: Accurate estimation of the velocity model is one of the challenging steps in seismic data imaging from anisotropic media. Constant velocity assumption on a horizon in different parts is not always correct and if a migration with incorrect velocity happens, position of the events, especially in depth migration, are not achieved properly. Therefore, in order to get closer to reality in seismic imaging it is better studied media to be considered anisotropic. In current study, NIP tomography method as one of the methods that best define the travel time of reflected events, was chosen to estimate the velocity model. In this technique, travel time information are automatically extracted from the Common Reflection Surface Stack, as a form of attributes, called kinematic wave field attributes. These indicators are parameters of two types of waves, called the normal wave and normal-incidence point wave. The initial velocity model plays a significant role in preparation of a final velocity model of migration. In NIP tomography technique in order to determine initial velocity model, it is assumed that velocity increases linearly with depth. Anisotropic parameters of VTI media will also be added to the model so as to do a accurate seismic imaging. The result was a velocity model in which anisotropy was included. Then the migration velocity was don using this velocity model. The achieved result showed that migration section with considering vertical anisotropy has manifested more reflection events with higher resolution than the migration section without considering vertical anisotropy.
Keywords:
#Anisotropy #Vertical transverse isotropy #Tomography #Kinematic wave field attributes #Normal-incidence point wave Link
Keeping place: Central Library of Shahrood University
Visitor: