The Application of 3-D Seismic Data in Carbonate Reservoir Modelling
Jurgen Grotsch and Andre van den Berg
Predictive 3-D geological modelling of carbonate and clastic hydrocarbon reservoirs is problematic in an early stage of field appraisal or development when only limited data are available. This holds especially true because previously 3-D seismic data could not be fully incorporated in the actual modelling process. Hence, in reservoirs, which have complex growth morphologies and a highly variable internal facies architecture - like carbonate build-ups - geological uncertainty is difficult to evaluate quantitatively during field assessment and development planning.
In the investigated case study, 3-D seismic interpretation indicates complex sedimentary geometries with localised progradation due to off-bank transport alternating with rapid vertical aggradation of the build-ups. Successive reduction of size during build-up growth (backstepping) appears to ultimately cause demise of carbonate production. In order to allow preparation of 3-D reservoir models in such a case, a modelling functionality has been developed, which enables to merge seismic scale observations with sub- seismic scale information from well data. Reservoir geological models based on the 3-D seismic data can be exported into the existing modelling functionality for property modelling. Such allows calculation of hydrocarbon volume for the generated scenario(s) independent of contentional mapping packages.
With the full integration of 3-D seismic data, production geologists, reservoir engineers and seismic interpreters are able to rapidly assess different geological scenarios already in a pre-development phase. The 3-D static and dynamic models allow quantitative assessment of uncertainty independent of statistical analysis while honouring available petrophysical, geological and geophysical data.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California