The upper Minnelusa Formation has been an active exploration target in the northeastern Powder River basin, Wyoming, since 1960. To date, over 200 million bbl of oil have been produced from the upper Minnelusa Formation. Production is derived from eolian dune sands encased in shallow-marine carbonates. Hydrocarbons are accumulated by (1) erosional truncation of reservoir sand, (2) facies change from reservoir sand to impermeable marine carbonates, and (3) structural closure.

Integration of advanced seismic techniques with abundant well data is used to delineate reservoir sands with favorable trapping geometries. Resolution limitations on current seismic data are caused by the inability to delineate thin beds in the frequency ranges that can be acquired in the field and retained in the final processed sections. Seismic dip lines and geologic data from Timber Creek, Robinson Ranch, Raven Creek, and Dillinger Ranch fields illustrate the recognizable seismic response to the productive Minnelusa Formation reservoir.

End_of_Article - Last_Page 870------------