Quantifying One and Two Dimensional Lateral Heterogeneities in Fluvio- Deltaic Reservoirs Using 3-D Seismic Data

Anil Deshpande, Peter B. Flemings, and Jie Huang

We document scale-invariant statistics and strong anisotropy in rock properties from well log and 3-D seismic data in fluvial/deltaic reservoirs in the El 330 Field, Gulf of Mexico. The scarcity of well log data in the lateral direction necessitates the use of lower resolution seismic data to quantify lateral heterogeneity. Spectral analysis of two dimensional seismic horizon slices and one dimensional traces extracted from the 3-D data cube reveal scale invariant behavior with a characteristic correlation parameter (ß) in both dimensions. This parameter captures the degree of correlation in profiles or surfaces (ß=0 for white noise). Two dimensional analysis of the horizon slice indicates a (ß) value of approximately 2.0 while analysis of one dimensional profiles from the same slice reveal an anisotropy along depositional strike and dip with (ß) values of 1.6 and 2. 1, respectively. The higher correlation observed in the direction of stratigraphic dip may reflect the stratigraphic fabric associated with channel systems. This one dimensional lateral variability in seismic data also matches the variability in higher resolution horizontal well log data suggesting a scale invariant behavior over approximately 3 orders of magnitude (1-1000 feet). Different depositional environments within specific systems tracts may have characteristic correlation parameters that provide insight into one and two dimensional lateral variations of reservoir heterogeneity. Correlation parameters obtained in these environments may then be used to quantify ock fabric and provide constraints in the simulation of rock property fields in the inter-well region.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California