.JPG)
Dravis
Interests, Inc.
Carbonate Reservoir Exploration Studies
Dravis Geological Services works with clients to develop improved strategies for exploring subsurface carbonate facies and sequences. An integrated approach is used to accomplish the following: (1) synthesize regional stratigraphic and structural information using client-based data and/or available literature; (2) evaluate nearby well or field data to establish the general environmental setting and resolve existing or potential play relationships; (3) generate regional stratigraphic cross sections when warranted; (4) develop guidelines from comparably-aged plays in the basin or elsewhere; (5) work with geophysicists to tie these guidelines into existing seismic data bases.
Remember, stratigraphy does not control facies, contrary to popular sequence stratigraphy dogma. Depositional setting dictates the types of facies developed and their distribution. To explore successfully, you must understand the environmental setting which can only come from "looking at the rocks." Stratigraphy results from the accumulation of depositional facies, and is controlled by physiographic setting.
.jpg)
This regional stratigraphic cross-section of Devonian Sequences across Comet Platform, NW Alberta, Canada showing the results of an integrated core, thin section and log study (see Dravis, 1992). Comet Platform is over 25 miles across in places. Upper Keg River pools produce oil from dolomitized cycles of platform-interior cycles 7-12 meters thick. Reactivated basement faults delivered hot diagenetic fluids which dissolved certain dolomitized facies in these cycles, creating the reservoir's secondary porosity. These faults also created closure (15-25 meters) for hydrocarbon entrapment. This fault closure created a seismic expression misinterpreted for years as reflecting small-scale pinnacle reefs. However, looking at the rocks properly showed that these sequences were comprised of more restricted subtidal and peritidal facies.
COMPLETED PROJECTS
- Cretaceous Glen Rose Formation, Maverick Basin, Texas
- Jurassic and Cretaceous, northeastern Gulf of Mexico (offshore)
- Pennsylvanian, Eastern Shelf, west Texas
- Devonian Upper Elk Point Group, western Canada
- Cretaceous Edwards Group, south Texas
- Devonian of Russia (Timan Pechora Basin)
- Devonian Jean Marie Formation, western Canada
- Pennsylvanian Desert Creek dolomites, Four Corners Platform, New Mexico
- Devonian Wabamun Formation, western Canada
- Devonian Slave Point Formation, western Canada
- Jurassic and Cretaceous, Mozambique
- Middle Cretaceous, offshore Angola
- Tertiary, Andaman Sea
- Cretaceous, Neuquen Basin, Argentina
- Jurassic Haynesville Formation, east Texas
- Devonian Swan Hills Formation, western Canada
- Jurassic/Cretaceous, offshore Nova Scotia
- Devonian Nisku Formation, western Canada
- Mississippian Elkton Formation, western Canada
Dravis Interests and Dravis Geological Services can be contacted by email, by phone at (713) 667-9844, or by mail at 4133 Tennyson St., Houston, Tx 77005-2749.