Some of the most productive hydrocarbon formations in the Michigan Basin are characterized as hydrothermal dolomite.
At the Michigan Geological Repository for Research and Education at Western Michigan University, we conducted research for two years through the Research Partnership to Secure Energy for America program to find out more about the differences between the productive and non-productive formations.
In the Niagaran (Silurian), we saw a general trend of increasing dolomitization shelfward, with limestone predominant in more basinward positions. One of our major findings was that these facies types are directly related to reservoir porosity and permeability in these dolomites, which increases the predictability of reservoir quality in these units. This pattern is consistent with our original hypothesis of primary facies control on dolomitization and resulting reservoir quality at some level. The identification of distinct and predictable vertical stacking patterns within a hierarchical sequence and cycle framework provides a high degree of confidence at this point that the results should be exportable throughout the basin. Data was derived from detailed analysis of cores archived at MGRRE.