Conoco Inc. said it discovered good indications of hydrocarbons in the Cambrian Tapeats sandstone and Muav limestone at a wildcat in southern Utah's Grand Staircase-Escalante National Monument.
The company was to decide within a few weeks whether to continue exploring the area. It said results of the well on state lands changed its exploration concept there and that it will not drill a location proposed nearby on federal lands.
Conoco plugged the 2 Reese Canyon-State, in 32-39s-5e, Kane County, at TD 11,911 ft. The well bottomed in metamorphic rocks of Precambrian age.
The company said hydrocarbons were present in volumes insufficient to establish commercial production at this well site. Geophysical logs indicate Tapeats, Conoco's primary objective, and Muav to be fully charged with gas, said Lee Allison, Utah Geological Survey director. No Chuar Group or other Precambrian sediments were encountered.
The gas consists of mostly methane with traces of oil, Conoco said without revealing components or volumes.
Porosities are low at Conoco's well site, but Tapeats is porous and permeable at other wells in and around the monument, Allison noted. For instance, BHP Petroleum Pty. Ltd.'s 28-1 Federal, in 28-33s-7e, Garfield County, on the Circle Cliffs anticline about 38 miles northeast, flowed 5 MMcfd of CO2 from Tapeats. Wells on the Escalante anticline northeast of Upper Valley oil field flowed CO2 at even higher rates (OGJ, Apr. 23, 1984, p. 53).
Conoco said results from its well, on the crest of the Rees Canyon anticline, indicate that oil and gas will be trapped on the flanks of the structure, having been displaced there by hydrodynamic forces. Such is the case at Upper Valley field, on the monument's northern boundary, but no other wells have been drilled off-structure in the basin, UGS said.
"Future well locations will now have the possibility of multiple pay objectives in the Kaibab, White Rim, Mississippian, Muav, and Tapeats formations," Conoco reported to the state. UGS is studying the region's Cambrian potential using data from the four or so wells that penetrated it and outcrop data from the Grand Canyon to the southwest in Arizona.
Conoco is considering whether to drill on the flank of the Rees Canyon anticline or perhaps on the next structure to the southwest, the Smoky Mountain anticline. A checkerboard of state school trust lands dot the 176,000 acre monument, generally taking up 3-4 sq miles of each 36 sq mile township.
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