1. Reservoir Model of Northern Platform, Sacroc Field
F. Jerry Lucia, Charles Kerans, Fred Wang, Hongliu Zeng
Bureau of Economic Geology
Jackson School of Geoscience
The University of Texas at Austin

2. Make small production table
Salt Creek
356 MMBO
Cogdell
264 MMBO
Sacroc
1,264 MMBO
From oil atlas
Make small production table

4. Structure Top of Sacroc North Platform

5. The Sacroc reservoir is a carbonate platform composed of four Canyon sequences and two units in the Cisco; Early Cisco 1 and Late Cisco.

6. This porosity-permeability plot illustrates the problem in constructing a petrophysical model for the Sacroc field.

7. Problem Approach Only porosity and gamma-ray logs available.
Highly variable rock fabrics typical of icehouse conditions.
Approach
Calculate average apparent rock-fabric number from core data for each stratigraphic layer.
Calculate permeability profile for each well using apparent rock-fabric number from stratigraphy and total porosity from logs as input into global permeability transform.
Interpolate permeability between wells constrained by seismic stratigraphy.
Only porosity and gamma-ray logs are available. Permeability is calculated using average “transform” numbers in the global transform equation.

8. Apparent Rock Fabric Number Total Porosity (fraction)

9. Apparent Rock Fabric Number
ARFN =10^(( *LOG10(cpor)-LOG(Cperm))/( *LOG(cpor)))
ARFN =10^(( *LOG10(cpor)-LOG(Cperm))/( *LOG(cpor)))
Apparent Rock Fabric Number
Assuming total porosity = interparticle porosity
ARFN =10^(( *LOG10(cpor)-LOG(Cperm))/( *LOG(cpor)))
ARFN = 2.8
Cycle 2
ARFN = 1.6
Cycle 1

10. The Sacroc reservoir is a carbonate platform composed of four Canyon sequences and two units in the Cisco; Early Cisco 1 and Late Cisco.

11. CN 3
CN 2