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Time-lapse Waveform Inversion for a Compacting Reservoir
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 75th EAGE Conference & Exhibition incorporating SPE EUROPEC 2013, Jun 2013, cp-348-00849
- ISBN: 978-90-73834-48-4
Abstract
For time-lapse imaging, full waveform inversion (FWI) can be used as a powerful tool to resolve high resolution velocity changes in the subsurface. In the past, the application of FWI for time-lapse analysis mostly has been limited in a non-compacting reservoir setting in which the time-lapse responses are assumed to be localized in a small region. In this study, FWI is used to investigate the time-lapse problem for a compacting reservoir in which physical parameters in regions other than the reservoir change as a result of production-induced changes in the reservoir. A synthetic test is designed to demonstrate FWI’s ability to image velocity changes in the reservoir as well as with variations in the overburden. For the real case study, ocean bottom cable data from the Valhall field are used for inversion. Time-lapse FWI are performed using the conventional approach that inverts each vintage of time-lapse data independently; and the residual time-lapse waveform inversion (RTWI) method that inverts the observed data difference instead. Inversion results show that the RTWI method is out-performed by the conventional method in the presence of noise.