About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 89, No. 11 (November 2005), P. 1493-1517.

Copyright copy2005. The American Association of Petroleum Geologists. All rights reserved.

DOI:10.1306/07050504121

Classification and characterizations of biogenically enhanced permeability

S. George Pemberton,1 Murray K. Gingras2

1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E3; [email protected]
2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E3; [email protected]

ABSTRACT

Recent research shows that ichnology has significant application to production geology. As such, permeability enhancement in bioturbated media has been recognized in five interrelated scenarios: (1) surface-constrained textural heterogeneities; (2) nonconstrained textural heterogeneities; (3) weakly defined textural heterogeneities; (4) diagenetic textural heterogeneities; and (5) cryptic bioturbation.

Our data demonstrate that substrate-controlled ichnofossil assemblages can enhance the permeability and vertical transmissivity of an otherwise relatively impermeable matrix. Permeability enhancement develops when burrows excavated into a firm ground are filled with a contrasting sediment from the overlying strata. Fill contrasting with the encasing firm-ground substrate leads to anisotropic porosity and permeability. The same concept can be applied to carbonate reservoirs, where burrow fills are subjected to different diagenetic phases. This may also lead to anisotropic porosity and permeability that can have dramatic effects on reserve calculations.

If the burrow fills have enhanced permeability but burrow effects are not recognized, reserve calculations will be too low. Likewise, if the burrow fills have reduced permeability, the reserve calculations may be too high. Understanding the flow dynamics of the resulting anisotropic permeability provides a potentially powerful reservoir-development tool. The implications are far reaching, particularly pertaining to calculations of reserves and their deliverability.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Protected Document: $10
Internal PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].