Rios, CristianAlnabulsi, Salam2016-01-292016-01-292016-01-292016Alnabulsi, S. (2016). Improved Downward Wavefield with Applications to Reverse Time Migration (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26476http://hdl.handle.net/11023/2797In this research, we introduce a new technique for wave propagation which produces a lesser amount of reflections in the resulting wavefield. Using these wave-fields in the Reverse Time Migration scheme aims to decrease the negative effect of the multiples that occur in the imaging process. Based on the technique stemming from the absorbing boundary conditions, we implement these conditions inside the domain to generate a forward wavefield while minimizing reflections when going through horizontal interfaces. We test two types of velocity models: elastic and viscoelastic. The benefit of using the viscoelastic model is that it takes into account the attenuation incurred by fluid fill in porous media and, hence, model the effect of amplitude reduction in the imaging process. The finite difference method was used to generate the compressional wavefield in the elastic model, while the finite element method was used for the viscoelastic model. The images were generated using the cross-correlation and the normalized imaging conditions. Finally, we test the approximated velocity models in order to mimic real-field applications. The application of reverse time migration, under this new technique not only detects interface locations, but also creates structural images, and it can identify different types of the saturated fluid in porous media.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Education--MathematicsGeophysicsMathematicsRTMWave equationMigrationFDMFEMdoctoral thesis10.11575/PRISM/26476