Print this pageFrom Well-Log Electrofacies to Calibrated Seismic Facies Modeling to Predict Stratigraphic Traps: Examples from Jurassic Carbonate Reservoirs, Northern Kingdom of Saudi Arabia
The Jurassic contains the world-class hydrocarbon source rocks and most significant oil reservoirs in the Kingdom of Saudi Arabia. Saudi Aramco has pursued a rigorous program to predict stratigaphic traps in Jurassic carbonate reservoirs. This has been accomplished by integrating sequence stratigraphic analysis, 3D seismic interpretations, core-based rock typing and well-log electrofacies modeling using “Facimage”, and calibrated seismic facies modeling of 3D seismic volumes.
A workflow that transforms all available core, well-log, petrophysical, and seismic data into three dimensional models has been established for predicting stratigraphic traps of Jurassic carbonate reservoirs. The workflow involves the following four key processes: 1) Unraveling the stratigraphic framework and reservoir architecture by integrating core, well correlations, and 3D seismic interpretations; 2) Core-based rock typing by integrating core descriptions, petrographic data, and core plug analysis; 3) Construction of Facimage models for selected “Reference Wells” that are stratigraphically and geographically representative by integrating core-derived rock types and edited/normalized log curves. Multiple Facimage models can be constructed and rigorously tested for reference wells. The final optimized Facimage model can be used to predict electrofacies of the entire stratigraphic interval for selected “Application Wells”. 4) The generated electrofacies can be upscaled to seismically detectable level and are output as numerical codes for inputting into the calibrated seismic facies modeling. This is achieved using state-of-the-art technologies for seismic classification analysis, integration, and visualization.
The end products of calibrated seismic facies, rock types and porosity models provide lateral and vertical facies changes of reservoirs and seals within 3D volumes, which are critical elements for defining stratigraphic traps. The Middle and Upper Jurassic reservoirs have been taken as examples for the above approach. Preliminary results have demonstrated that existing analogue and potential new stratigraphic traps can be successfully predicted.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil