HR: 0800h
AN: MR11A-0914    [Abstracts]
TI: Rock Physical study on an Upper-Palaeozoic Chert and Carbonate Interval in Wells from the Eastern Norwegian Barents Sea.
AU: * Colpaert, A
EM: arnout.colpaert@ig.uit.ni
AF: Department of Geology,University of Tromso, Dramsveien 201, Tromso, 9037 Norway
AU: Mienert, J
EM: juergen.mienert@ig.uit.no
AF: Department of Geology,University of Tromso, Dramsveien 201, Tromso, 9037 Norway
AU: Fotland, B
EM: bentef@statoil.com
AF: STATOIL ASA, PB 40, Harstad, 9481 Norway
AB: Due to their general interest as hydrocarbon reservoir, the Upper Palaeozoic chert and carbonate interval in the Norwegian Barents Sea has been investigated from seismic data and well logs. We established a framework for geophysical well log analysis and reservoir characterization for the Finnmark Platform, an area situated in the South-Eastern part of the Norwegian Barents Sea. The interval is composed by approximately 600 m carbonate facies covered by a 60 m interval of spiculitic chert facies. The carbonate facies is characterized by lateral and vertical lithological variations including limestones, dolomites, evaporites and clastic material. The spiculitic interval exists in spiculitic chert and clay alternated with limestones. Data extends over an area with different palaeo environments from inner platform settings to continental slope and even basinal settings. Log curve data from four wells were processed through geophysical well log analysis using Powerlog and Matlab. Multi-well trend analysis was performed for a diagnostic modeling of the rock physical parameters. The examination of the variation of petrophysical properties, and how that variation transfers into the elastic domain is a key to the correlation of rock properties and the seismic attribute information. The final goal is to improve porosity and mineralogy predictions in pseudo-wells from 3D seismic data. The analyses of cross plots allow distinguishing several intervals which in certain cases correspond to individual stratigraphic units. The spiculite interval shows for example different rock types based on rock physics and these parameters can be linked with seismic. For the synthetic seismogram an s-wave velocity log has been modeled. We observed that for several lithological intervals such as the mixed limestone-dolomites and spiculites the Greenberg-Castagna model fitted the best, but for pure dolomite intervals the Krief model is more accurate. Furthermore, for the purest limestone the best fit was obtained for the differential effective medium equations. These intervals should be treated differently for obtaining the best fitting velocity-porosity relations.
DE: 5102 Acoustic properties
DE: 5114 Permeability and porosity
DE: 5199 General or miscellaneous
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting