ABSTRACT: Reservoir Conduit Systems: Assessing Lithohydraulic Units within the Cardium Formation, Alberta, Canada

KRAUSE, FEDERICO F., SIEGFRIED D. JOINER, KEITH B. DEUTSCH, DEBORAH A. NELSON, and JOHN C. HOPKINS, University of Calgary, Calgary, Alberta, Canada, and SELIM G. SAYEGH and P. ROSEMARY FRENCH, Petroleum Recovery Institute, Calgary, Alberta, Canada

Cardium Formation reservoir conduit systems comprise a wide range of geological elements that are present over a wide range of physical scales. Cardium Formation reservoirs typically comprise sandstone and conglomerate compartments, often separated by mudstone and sandy mudstone envelopes, were characteristic textural attributes, including grain size, mineralogy, and mixtures of the latter two, sedimentary structures, porosities, permeabilities, wettabilities, resistivities, radioactivities, sonic velocities, and capillary pressures define five dominant lithohydraulic units.

Where conglomerate and sandstone compartments are stacked and segregated, the conglomerate's high flow capacity is detrimental to hydrocarbon recovery, because injection fluids bypass sandstones and hydrocarbon recovery is reduced. At kilometer scales, recently identified clinoforming and offlapping sandstones impart a sedimentary structure to Cardium Formation reservoirs that necessitates reassessment of water injection and production well locations.

Experiments with sandstone reservoir cores flooded with CO2-enriched brines and data from waterflooding indicate that siderite and calcite are unstable at reservoir conditions. This experimental work suggests that permeability losses will occur from the release of insoluble fines held within calcite and siderite frameworks. Mercury capillary pressure experiments with sandstone cores of lithohydraulic unit four indicate that mercury recovery efficiency increases with decreasing permeability and porosity. The latter behavior may reflect a dual porosity system within this lithohydraulic unit.

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