Special presentation from the discoverer of Wolverine's 17-1 Kings Meadow Ranch well, which hit 1,000 feet of Navajo Sandstone pay in Utah's Sevier County in late 2003.
Structural Architecture, Petroleum Systems, and Geological Implications for the New Hydrocarbon Province of the Covenant Field Discovery, Sevier County, Utah
By Douglas K Strickland, Wolverine Gas and Oil - Presenter
Dan Schelling (Structural Geology International), Dave Wavrek (Petroleum Systems International), Keith Johnson (WGO), John Vrona (WGO).
Structural analysis, seismic interpretation, and organic geochemistry are all part of the petroleum systems synthesis that contribute to the Covenant Field discovery in Central Utah by Wolverine Gas and Oil Corporation. The Kings Meadow Ranch 17-1 penetrates a highly porous and permeable reservoir in the Jurassic Navajo sandstone which contains a 450 foot oil column.
The Covenant Field is located along a frontal structural uplift to the Central Utah thrust belt, where Late Cretaceous-Early Tertiary compressional deformation resulted in the development of thrust faults and associated hanging wall anticlines buttressed against the ancestral Ephraim extensional fault. The traps are charged from Mississippian foreland basin sediments to the west of the discovery, and hydrocarbon generation was driven by the initial sedimentary loading (oil generation) followed by tectonic loading (gas generation) associated with the evolving thrust belt. Evaporite deposition in the overlying Arapien formation provides a highly effective seal for the accumulations. Jurassic extensional faults may be critical in defining the location of thrust faults and antiformal stacks, which in turn define structural traps along this newly discovered onshore hydrocarbon province.
For additional information
go to the AAPG Explorer article online about Covenant field at
Excerpt of AAPG Explorer article
Wolverine's discovery well, the 17-1 Kings Meadow Ranch, hit 1,000 feet of Navajo Sandstone pay in Utah's Sevier County in late 2003.The Covenant area of interest is a strip about 75 miles long and 20-30 miles wide along the Central Utah Overthrust.The entire thrust belt system extends north into Canada, where it is flanked by numerous Alberta fields. Another productive province lies on both sides of the Wyoming-Utah border.Wolverine completed and began producing the Covenant discovery well in May 2004, and its second well in September 2004.To date, those wells have produced a cumulative total of 210,00 barrels, Strickland said.Covenant wells produce good-quality, 40-degree gravity crude and show a very low gas-to-oil ratio, he said. Production from each of the field's first wells now averages 850 barrels per day.
"We're stepping up that production systematically -- we're designed for 1,500 barrels a day," Strickland said.Nearest significant production is from fields at the edge of the Uinta Basin, about 120 miles to the northeast and unrelated to thrust belt geology, he said.He sees the Anschutz Ranch East Field in the Wyoming-Utah trust trend as a closer analog. On the Wyoming side, the productive zone is called the Nugget, the Jurassic equivalent of the Navajo Sands.Wolverine, currently drilling its fourth Covenant well, directionally drills several development wells from one pad.Strickland expects the company will drill nine wells on 160-acre spacing this year, with the possible addition of a water-disposal well.
For future drilling, Strickland said the 500,000-acre play area could contain at least 25 structural closures, five of them on the producing unit.Should field sizes range from 1,000-4,000 acres, as he expects, the Central Utah Overthrust will yield years of fruitful exploration in multiple producing areas.