Date of Award


Degree Name

Master of Science



First Advisor

Dr. David A. Barnes

Second Advisor

Dr. William B. Harrison III

Third Advisor

Dr. John D. Grace

Access Setting

Masters Thesis-Open Access


Core samples and petrophysical data from three reservoir intervals within the Middle Ordovician St. Peter Sandstone in the Michigan basin were utilized to assess the reservoir performance. Each reservoir interval coincides with major sedimentary facies which are in gradational contact with one another vertically and laterally throughout the basin. Reservoirs in the lower portions of the formation (reservoir type 1) are dominated by meso-intercrystalline porosity. This predominantly quartz cemented reservoir rock type is characterized by low porosity with high permeability, moderate pore apertures, and moderate irreducible water saturation. Reservoirs at the top of the formation (reservoir type 3) are dominated by clay-rich, well sorted, fine- to medium-grained sandstone. The abundance of micropores with small pore apertures is responsible for the typically moderate porosity, low permeability, and high irreducible water saturation. Reservoirs below reservoir type, (reservoir type 2) consist of well sorted, uncemented, medium-grained sandstone. Macro intergranular pores with macro pore throats produce relatively high porosity and permeability, and low irreducible water saturation.

Included in

Geology Commons