Petroleum Geology

Strata

Ryersee Field produces oil from Middle Pennsylvanian Marmaton and Cherokee Group sandstones, and from Mississippian cherty carbonates. Gas at the top of the Lower Permian Chase Group is also structurally trapped at approximately 2250 feet (690 m) depth. The Chase Group is composed of a cyclical succession of dolomites and shales in this part of Kansas.

Structure

The SSW-plunging Bazine anticline is expressed at the top of Mississippian strata, as well as at the shallower Chase horizon. Chase gas wells are spotted on this structure map. Although the Pabst and Ryersee fields are separate oil accumulations, their gas in the Chase Group appears connected.