3D Seismic Attribute Analysis of the Jurassic Entrada/Curtis Sandstone Play, Uinta Basin, Utah

O'Neal, Ryan J.¹, R. William Keach², Thomas H. Morris¹, John H. McBride¹ (1) Brigham Young University, Provo, UT (2) Landmark and Brigham Young University, Provo, UT

Erg-margin sandstones have been recognized as potential stratigraphic and combination traps especially when they are laterally associated with muddy marine-influenced facies. Gas productive reservoirs of this type have recently been discovered within the Middle Jurassic Entrada/Curtis Sandstones of the Uinta basin, Utah. A recent high quality 3D seismic survey of the North Hill Creek field has been studied at BYU courtesy of Wind River Resources. This approximate 26 square mile survey is located in the southeast portion of the Uinta basin. This survey has played an integral part in the discovery and continued development of this Jurassic play.

3D seismic attribute analysis, attribute quantification, and cross sectional views of the 3D survey have been useful in delineating reservoir quality dune complexes which serve as primary gas reservoirs in the Entrada/Curtis-Moab interval. Cross sectional views and four seismic attributes including amplitude, spectral decomposition, semblance and phase were analyzed from the 3D data set. Cross sectional views displaying toplap features, which likely indicate an unconformity between Entrada clinoforms below and Curtis planer beds above, may aid the explorationist in discovering this important seismic interval. Amplitude extraction maps have been created and are useful in indicating the geometry of dune complexes. Spectral decomposition maps are useful in delineating lateral changes in the thickness of dune complexes. In combination, these two seismic attributes were found to be very useful in high grading exploration targets within the play and aiding the explorationist in risk management.