Forward Modeling of Deepwater Outcrop Geobodies to Enhance Seismic
Interpretation
of Fluid and Lithology
Kathleen Baker* and Mike Batzle
Colorado School of Mines, Golden, Colorado
There have been many studies of how Direct Hydrocarbon Indicators (DHIs) can help (or hurt) us when trying to distinguish fluid effects on seismic
amplitudes. DHI’s have proven to be useful in identification of pore fluid types, but geologic complexities can impact the
seismic
signature in a way that may lead to misidentification of fluid indicators. Deep-water turbidite sequences have inter-fingered boundaries such as channel complexes, gradational contacts due to stratigraphic pinch outs, and abrupt changes in properties at scales well below
seismic
resolution. A better understanding of the lithologies and geometries that control fluid distribution can be achieved by using analog outcrop observations to enhance the
interpretation
of subsurface information such as well logs,
seismic
data
and regional geologic models. Here we present a case study of the Ursa field in the deep-water GOM and show how the integration of outcrop studies can enhance the
interpretation
of complex reservoirs in deep-water depositional settings. A methodology of the investigation is presented starting with linking the outcrop depositional system to the GOM depositional system, calibration and detailed analysis of GOM well log, rock and fluid properties to
seismic
data
. Forward and inverse modeling, and analysis of the DHI response. Also, examples of outcrops and 1-D and 2-D models are presented. The results show that these deep-water outcrop analog help better predict frequency and occurrence of turbidite sequences when combined with well log and
seismic
and DHI’s. One key insight is the lithofacies impact on
seismic
data
may be an alternative explanation for the occurrence of high amplitude
seismic
events, which may be misidentified as commercial hydrocarbon indicators.
AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands
AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands