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Simultaneous elastic inversion for carbonate reservoir characterisation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 19th International Petroleum and Natural Gas Congress and Exhibition of Turkey, May 2013, cp-380-00083
Abstract
Inversions of 2D and 3D seismic datasets were successfully applied to study a carbonate reservoir in the Thrace basin, North-Western Turkey. Structurally, the studied field is defined by a NW-SE oriented horst block. The limestone reservoir rocks are of Eocene age. Seismic data was acquired as a high resolution 2D survey and then processed in 2D and subsequently into a pseudo 3D cube. Several wells with standard wireline logs penetrate the reservoir. This study initiated a post-stack, seismic inversion which was applied on both, 2D lines and sections from the 3D cube. It was noted that differences in impedance of the two data types mainly originate from the better imaged 3D data while 2D lines show higher noise levels. Cubes of density, acoustic and shear impedances were calculated for reservoir characterisation by pre-stack simultaneous inversion. Despite limitations to data quality the pre-stack inversion results show a good match to well data and yield high correlation coefficients with reservoir properties. The 3D density cube was transformed into a series of probability cubes and used in subsequent facies modelling. The acoustic impedance cube was utilized as a secondary variable steering the pore volume distribution in the reservoir model.