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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Seismic
Attribute Analysis in Paleozoic Hydrothermal Dolomite
1 Rock Solid Images, 2600 S Gessner Ste 650, houston, TX 77063, phone: 713 -783-5593,
[email protected]
2 Rock Solid Images, 2600 S. Gessner, Suite 650, Houston, TX 77063
3 Offshore Operations, formerly at Seitel Data
, 50 Briar Hollow Lane, 7th Floor West, Houston, TX 77027
To optimize geophysical subsurface interpretation
, it proves beneficial to place
seismic
attributes into their proper geological
context. This case study captures prognostic exploration play characteristics for populating a geological model within which
each dominant reservoir property is expressed as a risk parameter that in turn can be resolved by a
seismic
attribute.
Seismic
attribute analysis permits illumination of specific subsurface compartments and associated reservoir properties,
specifically: 1.) fractures, 2.) dolomitization, and 3.) high porosity. For instance, fracturing can be detected via low similarity
values (event terminations) and dip azimuth maps, whereas the transition from tight limestone (non–reservoir) to porous
dolomite (reservoir) is paralleled by a characteristic impedance reduction coupled with a subtle polarity reversal. Variant
composite
seismic
signals can be binned using artificial neural network topology. Some wells drilled on impedance
anomalies encounter intraformational shale plugs that resonate at identical impedance values to porous dolomite, thus
decreasing the predictive power of impedance as a diagnostic attribute. However, this increased stratigraphic complexity is
resolved by geological
data
indicating that dolomitization should preferably occur at the formation base. Application of this
model doubles the chance of setting pipe in this North American play. A novel look at applied subsurface
interpretation
firmly based on geological models would lend itself to widespread use in the
seismic
attribute analysis of carbonates hosted
by the Arabian platform.