Modeling of Permeability Reducing Vertical Conformance Treatments

ABSTRACT Chemical treatments (usually polymer gels) are commonly applied to improve the vertical conformance of oil reservoirs by selectively reducing the permeability in some zones near the well. The results of such treatments have been sporadic and unpredictable; The objective of this work was to define those reservoir characteristics which lead to successful treatments and to provide guidelines for the application of conformance treatments by modeling them with a reservoir simulator. Several cases have been run to identify the reservoir properties that strongly influence the outcome of a conformance treatment. Among the conclusions that have been drawn from this study are: 1. A low level of reservoir crossflow is conducive to a successful vertical conformance treatment; 2. The contrast in the permeability-thickness product of the reservoir layers is a useful parameter in identifying treatment candidates; 3. Vertical conformance treatments reduce the amount of injected water needed to recover a given volume of oil; and 4. Little sensitivity to the level of permeability reduction is observed as long as the treated region was reduced to a permeability as low as that in the low permeability layer.

Modeling of Permeability Reducing Vertical Conformance Treatments Conference Paper