ABSTRACT: The Use of Whole Core Analysis and Pressure Buildup Data to Estimate Average Permeability: Examples from Western Canada

MCNAMARA, L. B., and N. C. WARDLAW, The University of Calgary, Calgary, Alberta, Canada

Reservoir description requires the integration of geology with core analysis and well-test data to assign values of permeability to grid blocks used in reservoir simulation. Before values of permeability are estimated for grid blocks, it is necessary to know whether permeabilities measured from whole cores can be averaged to represent flow at larger reservoir scales. This can be achieved by comparing permeability calculated from a pressure buildup test with core averaged data for the same test interval. Optimum core averaging methods and biases in core measurement can be identified and the reservoir model can be improved.

Permeabilities calculated using pressure buildup tests and measured from whole cores were compared from three areas in western Canada, including over 90 tests in 65 wells from both clastic and carbonate reservoirs. Within each area, and for each well, core data were averaged for comparison with values from pressure buildup tests.

In certain reservoir types (Crossfield dolomite, southern Alberta), core permeability is larger than those from pressure tests whereas in other reservoir types (Keg River reefs, northern Alberta) the reverse relationship prevails. These differences can be reconciled in terms of biases in core measurement and sampling combined with a reservoir model that recognizes the spatial distribution of major conductive and nonconductive units.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)