Pinedale Field: Geophysical
Applications in a Major Tight Gas
Field, Green River Basin, Wyoming, U.S.A
The Pinedale Field, one of the largest gas fields in the
Greater Green River Basin of southwest Wyoming, is being developed along with
Jonah Field, as a significant over-pressured, tight-gas sandstone reservoir in
the Upper Cretaceous Lance Pool. The Pinedale Anticline has a 5000 foot thick
gross hydrocarbon bearing section comprised of fluvial and flood-plain facies rocks deposited in a broad alluvial valley nearly
coincident with the anticline structure. Since the acquisition of the initial
3D seismic survey in the Mesa area in late 1999, Ultra has used 3D seismic data
to guide drilling location selection, define drilling hazards, and extend Lance
Pool production laterally and vertically on the anticline. Specialized seismic
processing has facilitated ability to identify stratigraphic
sweet spots in the field, over-pressure, and handle azimuthal
anisotropy. Efforts to better understand the inter-well geometry of sand bodies
and the behavior of the massive hydraulic frac'ing
techniques used to enhance production has lead to the use of cross well
tomography and micro-seismic frac monitoring to map
the orientation and fabric between wells. The interpretation and understanding
from these applications has enhanced the reservoir model and validated much of
the geological and geophysical
understanding of the Pinedale Field.