Developments in Wyoming and Idaho in 1957

Abstract

The number of exploratory wells, their average depth, total exploratory footage, success ratio and number of discoveries have all increased significantly over 1956. The only decrease was in geophysical activity, which was 36% less than in 1956. The greatest number of discoveries were completed in the Phosphoria formation, followed in order by Frontier, Mesaverde, Dakota, then other formations from Cambrian to Upper Cretaceous. The most exploration activity was in the Powder River basin, mainly in search for stratigraphic traps in Upper Cretaceous sands; which resulted in 3 of the 11 discoveries in the basin. The Bighorn and Wind River basins followed with emphasis on extensions and new pools and structural prospects. The Green River basin led in success ratio with 11 gas and 4 oil discoveries. The Julesburg, Hanna, Laramie, Shirley, and Jackson Hole basins also had a modest amount of exploration. One dry hole was drilled on a structural prospect in Idaho. The emphasis on exploratory drilling for stratigraphic traps has increased and is expected to continue increasing, along with a decline in seismic exploration for structures. There is an increased interest in gas, due to improved economic factors.