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Porosity Estimation in Carbonates from Joint FWI and Amplitude Inversion in Frontier Exploration
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 80th EAGE Conference and Exhibition 2018, Jun 2018, Volume 2018, p.1 - 5
Abstract
While performing seismic reservoir characterization in a frontier exploration setting, we need to look beyond the conventional approaches and incorporate novel techniques of geoscience. With an objective of predicting porosity for a carbonate prospect, we employ a variety of techniques from pseudo well location optimization, full waveform inversion (FWI), AVO conditioning of seismic, extended elastic impedance (EEI) chi angle screening, post stack inversion, spectral decomposition, edge attributes, followed by a rock physics guided porosity-velocity relationship (PVR) from well data. The seismic dataset used in this study is without well control, with the nearest two wells located 200 km away from the prospect. The well derived PVR for the carbonates was verified against wells in the Loppa High area, roughly 300 km west. A filtered version of the FWI velocity field was used as a low frequency background model and combined with a post stack relative inversion of the full stack to produce a full bandwidth velocity model. Finally, we transformed the full bandwidth velocity model to porosity using the PVR to obtain a porosity estimate in the carbonate prospect. The lower, mean and upper porosity estimates were made to encompass the uncertainties.