--> Abstract: The Nature of Dolomite Fabrics: Implications for Permian Hugoton Field and Jurassic Smackover Reservoir Models, by M. L. Barrett; #91004 (1991)
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The Nature of Dolomite Fabrics: Implications for Permian Hugoton Field and Jurassic Smackover Previous HitReservoirNext Hit Models

BARRETT, MARY L., Mobil Exploration and Producing U.S., Denver, CO

The complexity of predicting hydrocarbon recovery in dolomitized Previous HitcarbonatesNext Hit is often increased by two oversimplified assumptions. First, pore volumes are considered to reflect a supposed volume increase association with dolomite replacement. Second, the inheritance of earlier fabric and pore volume is not incorporated. In dolomitized rocks from the Lower Permian of Hugoton field, Kansas, and the Jurassic Smackover Formation, Alabama and Florida, a volume-for-volume replacement model dependent on previous fabrics has resulted in an improved prediction of Previous HitreservoirNext Hit quality distribution.

Predictive mapping of dolomite Previous HitreservoirNext Hit types begins with a stratigraphic model of original lithologic distribution and often associated previous diagenetic pore modifications. When the replacement dolomite pattern(s) is superimposed, distribution of different dolomite Previous HitreservoirNext Hit types results. In the Smackover Formation, isotopic data indicate possible dolomitizing conditions, but dolomite rhomb size and pore structure vary within similar geochemical overprints to reflect original fabric control.

Capillary pressure data from the Chase Group of Hugoton field also support a fabric approach to Previous HitreservoirNext Hit modeling. Equivalent nondolomitized and dolomitized Previous HitcarbonatesNext Hit do not systematically differ in pore volumes. Dolomite fabrics increased in pore size and continuity, indicating a recrystallization of the previous structure. Grouping mercury data of dolomitized rocks by original lithology (reflecting earlier grain and pore size distributions) results in distinct rock Previous HitcharacterizationTop values. These different population values can then be extrapolated three-dimensionally based on the boundaries of original lithologic distribution.

 

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)