Gramp’s field, in Archuleta County, Colorado, was discovered in 1935, and until 1946 practically no information pertaining to the field had been released for publication. This article sets forth not only details regarding the geology of the field, but also gives data pertaining to operations and production from the drilling of the first well to the close of the operating season in January, 1947. The oil is being produced from the Dakota sandstone (Upper Cretaceous) in which it has accumulated against an east-west fault crossing a north-south anticlinal axis. The average thickness of the producing part of the Dakota sandstone is 152 feet. All the producing wells are at an elevation of more than 8,000 feet and their average depth is 1,250 feet. The producing area of Gramp’s field is 127 acres, and the total production from April, 1937, when installation of storage and pipeline facilities was completed, to January, 1947, has been 2,598,644 barrels. Because of severe winters it is usually necessary to stop field operations from the beginning of January until the middle of April. Gramp’s field is unique in that it is privately owned and consequently is free from many State and Federal operating regulations.
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.