Since completion of the discovery well in March, 1943, 16 producing wells have been drilled in the Steamboat Butte field to the middle of 1947. Oil produced to that time totalled in excess of 4½ million barrels, and the proved reserves of the field rank it among the largest in Wyoming. Oil-producing formations are the Nugget of Jurassic age (oil discovered in March, 1943), and the Tensleep of Pennsylvanian age (oil discovered about a year later). Total ultimate recovery from the Nugget has been estimated as 8 million barrels and from the Tensleep as 50 million barrels.
The structure has an estimated closure of 350–400 feet, and the productive area of the Tensleep is 1,880 acres. The maximum thickness of the oil-saturated section in this formation is 300 feet.
Spotty showings of green oil occur in the Muddy, Dakota, and Lakota sands of Cretaceous age. Considerable gas reserves are present in the Frontier sands of Upper Cretaceous age, from which one gas well is furnishing fuel for lease operations and field development.
Figures & Tables
Structure of Typical American Oil Fields: A Symposium of the Relation of Oil Accumulation to Structure
Modern petroleum geology in the United States had its beginning in the first decade of the 20th Century when the U.S. Geological Survey began mapping the structure of the rocks in and near old fields in order to discover the various types of structural conditions under which oil and gas are trapped. Structural geology has evolved as a branch of the broader science far more rapidly than have methods of mapping the attitude of rocks at the surface. This volume, published in the late 1920s, was designed to afford authoritative and modern descriptions of the structure of typical oil fields in the United States. Each of the 39 fields contained here is described by an author who is intimately familiar with the available data. The relationship of structure at the surface and at depth for different terranes is clearly set forth wherever the strata are not parallel. The volume concludes with a summary paper on the role of geologic structure in the accumulation of petroleum. Fields include: Florence, Colorado; Stephens, Arkansas; Kevin-Sunburst, Montana; Bradford Pennsylvania; and Salt Creek, Wyoming.