Nicole D. Kron^1,, David H. Malone¹, Eric W. Peterson¹

This study involves the construction of a three-dimensional (3D) geologic model of Paleozoic strata that are part of an underground gas storage field in northern, Illinois, USA. The Pecatonica Anticline trends 60W and plunges gently to the southeast. It is 10 km long and 3 km wide, and verges to the NE. Six water wells and 22 gas wells were used to create the 3-D geologic model in Petrel using well tops as determined from wire-line logs. The following horizons were created for the Cambrian and Ordovician strata: the Ancell, Trempealeau, Franconia, Ironton-Galesvilles, Eau Claire Proviso A and B, Eau Claire Proviso C “Ligthsville (top), and Eau Claire Proviso C “Lightsville (bottom). The horizons, edges, and intersections were then color-coded and an initial model was created. In the model area, the “Lightsville”, which is the principal layer used for gas storage, has about 10 m of closure over 0.80 Km² with a volume 199x10-3 km³. No faults or other structural discontinuities that may influence gas migration are evident in the model area.

ordovician, cambrian, illinois, gas storage, three-dimensional geologic model, petrel