A Seismic Analysis of Differential Compaction in the Frasnian Duhamel Reef, South-Central Alberta

Abstract

The Duhamel reef is an isolated Upper Devonian Leduc Formation limestone bioherm, situated immediately NNE of the Bashaw reef complex in south-central Alberta. Although Duhamel has a relatively small basal area (less than 12 km2), this reef rises some 275 m above the platform facies. From seismic data we interpret that there is a raised peripheral reef rim that appears to be elevated about 25 m relative to the interior of the reef. Raised rims are considered to be diagenetic in origin and attributed to differential compaction within the reef complexes. Although late-stage accretionary growth about the periphery of the reef complex may have contributed to its development, we interpret the raised rim at Duhamel to be principally of secondary origin. This thesis is consistent with the incorporated seismic and well-top data. The facies within the reef rim have a lower seismic velocity than the facies within the structurally lower reef interior, consistent with the observation that the raised rim is generally more porous than the encircled and structurally lower lagoon and, therefore, constitute a preferred well-completion site. Optimal hydrocarbon recovery could be realized if all production wells were drilled into the raised reef rim. The Duhamel example shows that even relatively small Leduc reefs can exhibit raised rims and that these rims may be seismically visible. Before drilling, reflection seismic data should be acquired across similar reefs with a view to imaging and locating the complete raised rim, not simply its updip side, so that all parts of the rim can be tested by the drill.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Alberta; Devonian Reef; Differential Compaction; Frasnian; Hydrocarbon Recovery; Leduc; Porosity; Reef Rim; Reflection Seismic Data; Synthetic Seismogram; Woodbend; Diagenesis; Hydrocarbon Potential; Seismic Reflection; Canada, Alberta, Duhamel Reef

Geographic Coverage

Alberta, Canada

International Standard Serial Number (ISSN)

0098-3004

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1996 Elsevier Limited, All rights reserved.

Publication Date

01 Apr 1996

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