High Resolution Velocity Estimation Using Refraction And Reflection Fwi - The Fortuna Region, Offshore Equatorial Guinea
I.F. Jones, J. Singh, P. Cox, M. Warner, C. Hawke, D. Harger and S. Greenwood
Event name: First EAGE/PESGB Workshop on Velocities
Session: FWI Case Studies II
Publication date: 22 February 2018
Info: Extended abstract, PDF ( 495.23Kb )
Price: € 20
The primary objective of this project was to improve the understanding of the internal structure of the Viscata and Fortuna reservoirs, and this objective was met via clearer internal imaging of these reservoir intervals and the overlying gas-charged sediments. The underlying geophysical challenge was the presence of extensive, but small-scale low-velocity gas pockets, which gave rise to significant and cumulative image distortion at target level. This distortion had not been resolved in a vintage 2013 broadband preSDM project, as the velocity model was not sufficiently well resolved. But in the initial commercial phase of this project, high-resolution non-parametric tomography using improved broadband deghosted data enabled us to achieve the stated objectives. The follow-on work, considered here, deals with the use of full waveform inversion, to see if we could further delineate small-scale velocity anomalies, associated with the highly compartmentalized reservoir units.