In this paper are described the structure and related production in five oil and gas fields of the eastern coal field of Kentucky, namely (i) the Lee-Estill-Powell oil field, (2) the Campton oil field, (3) the Owlsey County gas field, (4) the Clay County gas field, and (5) the Elliott County oil field. The producing beds are Pennsylvanian, Mississippian, Devonian, and Silurian in age, most important being the Corniferous limestone of the Devonian. The major structural features of the general area are the Cincinnati arch and Paint Creek uplift, whose axes extend north and south, and the Pine Mountain a^nd the Irvine-Paint Creek faults and uplifts, whose axes extend east and west. These two systems of folding are dominant features in eastern Kentucky. The Cincinnati arch has had a marked effect on both structure and stratigraphy. It was probably a positive element throughout the time of deposition of the formations in these fields. Formations increase in thickness with distance from the arch, and minor folds parallel the arch. Subsequent folding and faulting with east and west axes were the result of pressure from the south. Production is related to structure only in a general way; the porosity of the sands and limestones seems to be the controlling factor for oil and gas accumulation. Several wells have been drilled in the Elliott County oil field proving the crest of the main fold to be dry, probably because of unfavorable sand conditions. An interesting feature of the map of the eastern coal field is the relation of the oil and gas production and the isocarbs to the major uplifts and faults. The Irvine sand pools, which produce 60 per cent of the oil in the state, lie along the flank of the Irvine-Paint Creek uplift, paralleling the Irvine-Paint Creek fault. The Wier pools, which produce 30 per cent of the state's oil, lie along the axis of the Paint Creek uplift. This close relation of production to uplift bears out the theory that oil was formed during, and as a result of, folding, rather than that it had been formed prior to the fold and had subsequently migrated into it. Folding seems essential to oil accumulation in eastern Kentucky, but the degree of folding must not pass beyond a certain point or the hydrocarbons will be changed to gas. The most favorable formations for producing oil are stratigraphically high, geologically young, and moderately folded. The probability of finding many new oil fields of importance is not large.
Figures & Tables
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 30 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. Fields include: McKittrick, California; Fairport, Kansas; Urania, Louisiana; Artesia, New Mexico; Burbank, Oklahoma; Cabin Creek, West Virginia; and Luling, Texas.