WENSRICH, MARTIN D., Occidental Oil and Gas Company, Houston, TX; and EDWARD E. CLERKE, Clerke Enterprises, Houston, TX
The Karst Reservoir Play is one of 10 clastic and carbonate play types that are currently being evaluated by the Occidental Oil and Gas staff along the Cretaceous Shelf Margin Trend in the Gulf of Mexico, U.S.A. The Karst Reservoir Play may be from a volumetric perspective the most significant play type in the trend, but it also carries one of the highest risks for commercial production. The traditional geologic model for karst reservoir development invokes carbonate dissolution by ground water along fracture planes. However, sulfuric acid derived from hydrocarbons may also play a significant role. Analogues from outcrops and fields in the Permian Basin of west Texas show that the reservoirs in this play type can yield rates of over 3000 barrels of liquids per day and that 100 million barrel fields may have an aerial extent of less than 200 acres. Geophysical modeling shows that there is a distinct seismic attribute response for the reservoir that can be quantified. Seismic workstation mapping techniques combined with the modeled seismic attribute characteristics can be used to generate prospects on 2D and 3D seismic data. Examples of prospects along the Cretaceous Shelf Margin Trend in the Gulf of Mexico, U.S.A. are shown.
WENSRICH, MARTIN D., and EDWARD E. CLERKE
AAPG Search and Discovery Article #90908©2000 GCAGS, Houston, Texas