Lessons in Exploration - Early History of Oil Development in NW Colorado

Larry Moyer

The story of the history of oil development in Northwestern Colorado will be told using vintage photos and maps dating to Territorial times. Several of the classical lessons in exploration will be demonstrated at the Rangely field including: 1) The Search for Oil Begins in the Library (Levorson), - The oil seeps at Rangely which were the focus of the first drilling were mentioned in publications by F.V. Hayden in association with the Geological and geographical atlas of Colorado and adjacent territory in 1877. 2) 'maintain a constant awareness that he does not know everything that may enter into his problem' (Pratt) is demonstrated by the early focus of exploration for the Dakota, which turned out to be an insignificant reservoir. 3) The best way to find new oil and gas is to drill deeper on a producing structure (?) was demonstrated by the drilling of the deeper Weber Sandstone reservoir in 1931. The 1930 plane table structure map made by two geologists is remarkably accurate compared to the Weber Sandstone Unit structure. Since the Weber Sandstone reservoir discovery was 29 years after the first oil production, it is an exception that proves the rule that the largest deposits are found first. 4) Waves of technological innovation in all aspects of the oil and gas industry convert resources into productive reserves are demonstrated by the use of rotary drilling with mud in 1931 to allow drilling below high volume natural gas in the Frontier Formation. The Fractured Mancos Shale reservoir in Northwestern Colorado has come full circle. At Rangely it was the first productive interval in 1902, and with the latest advancements in drilling and completion technology, this reservoir is currently an active target for operators in several basins in the Rocky Mountains.

AAPG Search and Discovery Article #90156©2012 AAPG Rocky Mountain Section Meeting, Grand Junction, Colorado, 9-12 September 2012