Arikaree Creek, Bolero, Old Homestead and Great Plains Oil Fields, Oddities or Potential Repeatable Opportunities, Southern Denver Basin, Colorado USA
The Arikaree Creek, Old Homestead, Bolero and Great Plains fields located in the Southern Denver Basin, Lincoln County, Colorado are examples of several fields discovered in the southern Denver basin since 2009. These fields lie along or are associated with wrench fault systems. The Pennsylvanian and Mississippian rocks in the southern Denver Basin are significantly underpressured at 0.24 to 0.28 psi per foot. The Great Plains Field (3.2+ MMBO) was discovered in 2009 with the initial well producing from the Cherokee “A” carbonate and Excello Shale at a rate of 600+ BOPD. The discovery well was drilled based on a 2D line that indicated a structural closure in the Pennsylvanian strata. Subsequent completions of the Cherokee “A” in adjacent wells through time indicated significant decline in reservoir pressure over a large area suggesting excellent reservoir continuity. Exploitation of the field than turned to completions in the Mississippian, Morrow, Ft. Scott and Marmaton reservoirs. Numerous dry holes and sub-economic wells have been drilled within the field itself. The Arikaree Creek Field discovered in 2012 is productive primarily from the Mississippian Spergen (Salem) Dolomite with additional completions in the Cherokee “A”. The Arikaree Creek Field (1.3 MMBO) based on 3D seismic represents a complex wrench fault system with three horsts features of which two are oil productive. Three wells have produced 60% of the production in the field and lie on the upper horst. The productive Spergen reservoir at Arikaree Creek is not productive in other structures adjacent to the field to date. An example of smaller structural features that produce from various Mississippian and Pennsylvanian carbonates is the Old Homestead Field (220+ MBOE). The Bolero Field (145+ BOE) is a stratigraphic trap in the Cherokee C zone and a structural trap in the Cherokee A zone of the Cherokee Formation. The production within all of these fields can be best described as erratic, unpredictable and difficult to exploit. The presentation will discuss many of these issues and provide a potential exploration model for these types of reservoirs.
AAPG Datapages/Search and Discovery Article #90357 ©2019 AAPG Rocky Mountain Section Meeting, Cheyenne, Wyoming, September 15-18, 2019