The Discovery Group is offering its database compiled over a 20-year period of Devonian and deeper tops in the Illinois Basin.  It has two areas of focus, detailed New Albany stratigraphy and Middle Devonian to basement tops.  It consists of a regional breakdown of the New Albany Shale with 470 digitized well logs over the shale section, and a database of tops from over 750 key deep penetrations, from the top of the Middle Devonian to Precambrian.  The latter were picked from hardcopy logs and key non-proprietary rasters are included in the study.  We have also incorporated tops from the state geologic surveys, sample tops and operator tops.  We have worked out unconformity picks and flag tops as eroded or never present. In total there are approximately 3700 wells with at least one top, brief header data and location.  From the tops database, we have generated a series of structure and thickness maps and cross-sections which are included as both Petra files and pdf files.  The entire Petra project will be delivered on DVD.  This is a completely digital product.  Over the last century, there have been at least 180,000 wells drilled in the Illinois Basin.  Most are shallow penetrations.  According to IHS information, approximately 14,500 wells bottom in Silurian and older formations. Our study incorporates a representative number of wells to give your company a running start to enter the basin.