Fracture, Stratigraphic, and Lithologic Analysis of the Niobrara-Equivalent Cody Shale WyomingNorthern Bighorn Basin,

Abstract

Unconventional shale reservoirs have become a major focus of petroleum exploration and production in North America over the past 15 years. USGS assessments of unconventional targets include the Cody Shale of the Bighorn Basin, Wyoming. To further appraise the unconventional play potential of this unit, this study will characterize the lithology, fracture patterns, and stratigraphic patterns in the Cody. Deposited during the Late Cretaceous in anoxic conditions while this area was inundated by the Western Interior Seaway and composed of thousands of feet of grey to black shale and interbedded sandstone towards the top, this formation has potential to become highly productive in the near future. When drilling horizontal wells, the fractures within the formation must be understood in order to make the most out of each fracture job. In order to achieve this, over 350 feet of core will be examined from a range of depths as well as outcrop studies from multiple sites around the basin. Outcrop studies will occur in the summer and fall of 2019. When looking at core and outcrop, fracture characteristics and distribution in the Cody Shale will be analyzed in order to define dominant fracture orientations, size, and patterns. Lithologic characteristics and clay content in the interbedded sandstone of this formation will also be examined for effects on fracture patterns. The results from this research will aid in assessing the probability of unconventional petroleum resources of this untapped unit in the Bighorn Basin, WY.

AAPG Datapages/Search and Discovery Article #90357 ©2019 AAPG Rocky Mountain Section Meeting, Cheyenne, Wyoming, September 15-18, 2019