The quality and distribution of many carbonate reservoirs are impacted by a complex diagenetic history, the result of fluid-rock interactions through the history of the reservoir. To understand such complexities, Machel and Buschkuehle documented petrography, stable isotopes, Sr isotopes, and fluid inclusions of the Devonian Southesk-Cairn Carbonate Complex of the Alberta Basin. The data reveal a paragenetic sequence of 24 distinct diagenetic phases, which can be grouped into 5 chemically and temporally distinct stages. Each burial-diagenetic episode had a different impact on the hydrocarbon reservoir properties of the reef complex – some (matrix dolomitization, thermochemical sulfate reduction, and the emplacement of secondary and tertiary anhydrites) impacted reservoir properties throughout the entire reef complex, whereas others (“squeegee” fluid flow) did not markedly impact reservoir properties, even though they left “remarkable” petrographic and geochemical traces.
Diagenesis of the Devonian Southesk-Cairn Carbonate Complex, Alberta, Canada: Marine Cementation, Burial Dolomitization, Thermochemical Sulfate Reduction, Anhydritization, and Squeegee Fluid Flow by Hans G. Machel and Beate Elisabeth Buschkuehle
Journal of Sedimentary Research, May 2008, v. 78, p. 366-389.