Interpretation of the Jurassic Entrada/Curtis sandstone play using seismic attribute analysis, Uinta basin, Utah

Ryan O’Neal.

Brigham Young University, Dept. of Geological Sciences

Provo, Utah

[email protected]

Erg-margin sandstones have been recognized as potential stratigraphic and combination traps especially when they are laterally associated with muddy marine-influenced facies (Fryberger, 1986; Chan, 1989). Gas productive reservoirs of this type have recently been discovered within the Middle Jurassic Entrada/Curtis Sandstones of Utah (Mark Eckels, Wind River Resources Corporation, personal communication, 2005). A recent high quality 3D seismic survey of the North Hill Creek field located in the southeast portion of the Uinta basin has played an integral part in that discovery.

Upon careful study of the 3D data set, we have found that 3D seismic attribute analysis and cross sectional views of the 3D survey have been useful in delineating reservoir quality dune and dune complexes which serve as the primary gas reservoirs in the Entrada/Curtis-Moab interval. Four seismic attributes including amplitude, spectral decomposition, semblance and phase were used to analyze the 3D data. Amplitude extraction maps have been created and are useful in indicating the geometry of the dunes and dune complexes. Spectral decomposition maps are useful in delineating lateral changes in the thickness of dunes and dune complexes. In combination, these two seismic attributes can be used to high grade exploration targets within the play and aid the explorationist in risk management.

AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid