Subsalt Imaging Using Walkabove and Walkaway VSP in the Transition Zone of the Red Sea
C. A. Planchart, M.J. Vega, J. Jiao, N. El Yadari and Y. K. Fadolalkarem
Event name: Fourth EAGE Borehole Geophysics Workshop
Session: Multi-Component Processing And Imaging
Publication date: 19 November 2017
Info: Extended abstract, PDF ( 751.11Kb )
Price: € 20
The transition zone in the Red Sea contains challenges for seismic imaging related to the complex bathymetry and presence of reefs. Also, the presence of salt bodies overlying the potential reservoirs causes weak illumination due to the defocusing of the energy and the weak reflectivity. While drilling a well, it was necessary to drill a side track due to operational reasons. Some unexpected lateral variations at the same depth were found between both wells separated by only 130 ft. As part of the exploratory efforts, several VSP surveys were acquired. We present a case study where several migration algorithms were evaluated to perform subsalt imaging. The image from walkaway VSP found the cause of the unexpected lateral variation. We also used the VSP data to explain the possible reasons of the poor imaging of the 2D surface seismic data.