Model-Centric 3-D Petrophysical Application Technology
Sung, Roger R.*1; Al-Wahabi, Khalid S.1
(1) Saudi Aramco, Dhahran, Saudi Arabia.
The complexity and heterogeneity of reservoirs makes it extremely difficult to characterize and predict recovery. Oil industry geoscientists and engineers have made strides in developing advanced petrophysical algorithms and formation evaluation techniques to understand the fluid flow mechanisms. These methods have been applied at the individual wellbore level. A new application technology has been developed to incorporate petrophysical methods and extend from well-centric to model-centric, to create 3D geological models. Saturation and permeability attributes in these 3D models — comprised of hundreds of millions of cells — offer a much clearer picture of the fluid flow pathways and connections that are essential to field development and planning.
Application technology has been developed to upscale water saturation from the small core-plug samples to the larger reservoir element, and further into the even larger 3D geological model of the field. The application plug-in (SWUP, UPscaled Water Saturation) has been coded under the 3D modeling environment to be seamless integrated with the rest of the geological modeling applications.
Uncertainty modeling challenges all aspects of interpretation and examines the uncertainty ranges of each variable. A much clearer reservoir understanding can be derived through hundreds of multiple uncertainty modeling realizations. A new Linux multi-core cluster has been incorporated to meet the large number crunching requirement of the uncertainty modeling.
New methodology has been introduced to capture and conserve the original heterogeneity in the upscaling process between two different data with different resolutions. It overcomes the shortcomings of the traditional averaging tools by including information on the vertical heterogeneity within each cell of the model. It also has been integrated within the Linux cluster computing environment. Uncertainty can be modeled and minimized through iterative processes.
We have applied these modules successfully in several Saudi Aramco fields, including Ghawar. Not only has pin-point accuracy been enhanced but also the turn-around time has been reduced by orders of magnitude. A major stride in understanding and modeling the heterogeneity of complex carbonate reservoirs was made. A paradigm shift of 3D petrophysics from well-centric to model-centric has been fostered.
AAPG Search and Discovery Article #90141©2012, GEO-2012, 10th Middle East Geosciences Conference and Exhibition, 4-7 March 2012, Manama, Bahrain