Matrix-controlled hydraulic properties of Mississippian and Pennsylvanian sandstones from the Michigan Basin

Hydraulic-conductivity measurements were made of 49 sandstone core plugs using a flow pump and a conventional triaxial confining apparatus. The sandstones tested are samples from the Marshall Sandstone and Grand River and Saginaw Formations, which are the principal bedrock aquifers in the Michigan basin. Sandstones ranging from poorly cemented to well cemented were selected to investigate matrix-controlled hydraulic properties as a function of degree of cementation. Hydraulic conductivities were measured for each sample over a range of effective stress (69 to 827 kilopascals); hydraulic conductivities for the sample suite range from 1.9 X 10 to 2.7 X 10 centimeters per second. This range of approximately seven orders in magnitude is indicative of local and regional differences in matrix-controlled hydraulic conductivities for Mississippian and Pennsylvanian bedrock aquifers in the Michigan basin.