Dravis Interests, Inc.

Dravis Geological Services

Carbonate Reservoir Development

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Fields of Specialization and Projects

Carbonate Exploration

Carbonate Reservoir Development

Carbonate Petrography

Core Studies

Training Seminars

About Jeff Dravis

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STRATEGY

Dravis Geological Services conducts reservoir development studies in both limestone and dolomite sequences. These studies integrate core and thin section observations with wireline logs and other engineering data. The result is development of a more rigorous stratigraphic framework for accurate mapping of porosity and permeability required for reservoir zonation. Benefits of this approach include: (1) more accurate reserve estimates; (2) more sophisticated models for enhanced recovery; (3) improved well excellence; (4) more complete and efficient field development, including field extensions, wedge-edges; infill drilling, and well deepenings; (5) sounder strategies for perforations; (6) increase in sweep efficiency; (7) delineation of dense permeability barriers; and (8) improved log interpretations.

Enhanced petrography utilizing blue-light fluorescence and/or diffused plane-polarized light techniques is employed to resolve the relationship between reservoir quality and depositional facies, especially in massively dolomitized reservoirs.

The approach outlined above was pioneered by Jack Wendte and Frank Stoakes in Calgary. This consultant worked with Wendte and Stoakes when they first applied this approach to the zonation of the Devonian Judy Creek Pool (>900 MMBOIP) in Alberta. Since then, this approach has been successfully applied to several other Devonian limestone and dolomite reservoirs. This stratigraphic approach is a fundamental part of "Actualistic Sequence Stratigraphy" developed by Wendte and Stoakes (1992, "Devonian-Early Mississippian Carbonates of the Western Canada Sedimentary Basin: a Sequence Stratigraphic Framework, SEPM Short Course Notes 28, 225 p.). These topics are covered in the seminar on "Carbonate Sequence Stratigraphy"

Cross section of part of the Devonian Judy Creek Pool, Alberta, Canada. Depositonal facies and cycles were constructed by applying principles of actualistic sequence stratigraphy pioneered by Wendte and Stokes. This approach created infill and field extension drilling opportunities, increasing the reserves of oil in place from about 830 MMBOIP to over 900 MMBOIP.

 

Figure from Wendte et al. (1992), reproduced with their approval.

COMPLETED PROJECTS

• Devonian Keg River and Muskeg Pools, W. Canada (dolomite reservoirs)

• Permian Seminole Field, Permian, W. Texas (dolomite reservoir)

• Ordovician Ellenburger Suggs Field, Eastern Shelf, W. Texas (dolomite reservoir)

• Devonian Mid-Kharyaga Field, Timan-Pechora Basin, Russia (highly altered

• mixed limestones and dolomites)

• Cretaceous Isis Field, offshore Tunisia (limestone reservoir)

• Cretaceous Sunniland Field, south Florida (limestone reservoir)

• Nafoora-Augila Field, Libya (limestone reservoir)

Dravis Interests can be contacted by email, by phone at (713) 667-9844, or by mail at Dravis Interests, 4133 Tennyson St., Houston, Tx 77005-2749