SCHELLING, DANIEL D.¹ and DAVID A. WAVREK^2
1Energy & Geoscience Institute, University of Utah, Salt Lake City, UT
²Humble Geochemical Services, Humble, TX

Abstract: Structural Geology and Petroleum Systems of the Madden Field, Wind River Basin, Wyoming

Located in the northeastern corner of the Wind River Basin of Wyoming, the Madden Field is characterized by a hanging wall anticline structural geometry and gas production from multiple stratigraphic horizons ranging from the Mississipian Madison Limestone to the Eocene Wind River Fm. In order to understand the geologic evolution and petroleum systems of the Madden Field, an integrated structural and geochemical study was conducted utilizing both surface and subsurface structural and geochemical data. Construction of a detailed balanced cross section has clarified the structural relationships between the South Owl Creek Thrust and the buried Madden Anticline. These developed as compressional structural systems during the Late Cretaceous-Early Eocene Laramide orogeny and were later overprinted by extensional deformation. Combined molecular-isotopic analyses of gas components indicate a vertical hydrocarbon compartmentalization across the Madden Anticline which coincides with a structural discontinuity at the Mesaverde Fm. level. In addition, high hydrogen sulfide and carbon dioxide contents of the Madison gases are recognized as a by-product of thermochemical sulfate reduction. Active hydrocarbon generation within Cretaceous source rocks has resulted in the development of overpressured stratigraphic horizons across the Madden Anticline. Both compressional and extensional fault systems have been utilized as vertical migration pathways since the onset of hydrocarbon generation in the early Eocene.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas