Carbonate reservoirs represent a major target within the U.S. and overseas. Delineating and improving recovery of remaining hydrocarbons are an important area of research. Occidental Oil & Gas Corporation of Houston recently hosted Reservoir Characterization Research Laboratory (RCRL) scientists Charles Kerans, Jerry Lucia, and Jim Jennings for a 5-day carbonate reservoir characterization workshop that focused on improved recovery methods developed by RCRL.

This course is designed for sponsors of the Bureau’s Reservoir Characterization Research Laboratory Industrial Associates group. Presentations to nonsponsors may be available through special arrangement. For more information e-mail Charlie Kerans, Jerry Lucia, or Jim Jennings.

Course Outline

Carbonate Reservoir Characterization
Reservoir Characterization Research Laboratory

GEOLOGIC FRAMEWORK AND 3-D FRAMEWORK MODEL CONSTRUCTION
Charlie Kerans, Instructor

  • Setting the stage for a successful stratigraphic interpretation
  • The basics of carbonate facies description for quantification of the geologic model
  • Sequence stratigraphy for modeling reservoir heterogeneity
  • One- and two-dimensional sequence stratigraphic tools
  • Application of tools to Cretaceous and Permian reservoirs

PETROPHYSICAL QUANTIFICATION
Jerry Lucia, Instructor

  • Development of a rock fabric/petrophysical classification of carbonate pore space
  • The rock fabric method for estimating permeability and original water saturation from wireline logs
  • Concepts and methods of constructing 3-D petrophysical models
  • Application of rock fabric method to Permian and Cretaceous reservoirs
  • The role of diagenesis in prediction and mapping of carbonate rock fabrics and pore space

GEOSTATISTICAL CHARACTERIZATION AND FLOW MODELING
Jim Jennings, Instructor

  • Spatial organization of carbonate porosity, permeability, and rock fabric
  • Short-range variability and the "I can’t see the forest for the trees" problem in carbonate permeability statistics
  • Quantification of spatial organization with trend models and spatial statistics
  • The effects of different carbonate heterogeneity scales on fluid flow
  • The effects of small-scale variability on core-log comparison
  • Scaleup customized for typical carbonate heterogeneities
  • Putting together the pieces: an outline for carbonate reservoir flow model construction
  • Future directions–outstanding issues in carbonate heterogeneity modeling, scaleup, and flow modeling

In carbonate reservoir characterization the target for enhanced production is commonly a relatively thin zone (50 to 300 ft) in a platform top position. In order to utilize the concepts of sequence stratigraphy in this setting, we have added to the traditional seismic geometric analysis a set of tools for high-frequency sequence analysis. This methodology weighs heavily on cores and logs to allow construction of reservoir models at the flow-unit scale that is essential for translating geologic models into engineering models. In the view shown, we start with the standard Exxon sequence model (a) and its representation in standard 3D seismic data (b) then continue to zoom in through the reservoir scale (c) to the flow unit scale (d) where much of the integration of geology, rock fabric studies, petrophysics, geostatistics, and engineering takes place.