Abstract: Structural Geology of Jonah Field as Determined from Subsurface Geology and 3-D Seismic

WARNER, EDWARD M.

Jonah Field, located in the northwestern arm of the Green River Basin, produces gas and condensate from abnormally-pressured sandstones of the Upper Cretaceous Lance Formation.

The field was originally thought to be a, basin-centered gas accumulation, but recent subsurface evidence, integrated with 50 squarer miles of 3-D seismic, demonstrate that it is a structural trap bounded on its updip and lateral margins by left lateral wrench faults. The downdip margin is unknown, but may extend under the Pinedale thrust east of the field. The eastern limit will be determined by economic considerations because the top of the gas accumulation gets progressively deeper.

Cross-sections and maps, demonstrate the structural geometry of the field.

AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado