Geology of the Gotnia Basin Shelf

Martin Rademakers and Khalid Shokair
Saudi Aramco, Dhahran, Saudi Arabia

Geology of the Gotnia Basin Shelf
During the Jurassic the Arabian Platform was the site of several intrashelf basins. While most of these basins were dominated by carbonate deposition, the Gotnia Basin was the site of significant evaporate deposition. This salt-bearing facies, called the Gotnia facies is present in Kuwait, Saudia Arabia and extends for unknown distance into Southern Iraq. Mainly underlying and commonly interbedded with the salt facies are organic rich carbonate sequences which are the dominate source rocks for hydrocarbon traps along the Rimthan shelf edge and within the Gotnia Basin. Time based hydrocarbon migration models indicate the Rimthan shelf received the dominate oil charge during the middle to late Cretceous. The Gotnia facies reaches its maximum thickness of 1500 feet in the Minagish area, located west of the Jauf-Burgan Anticline.
Analysis of recent 3D seismic data shows interesting relationships between the oil rich basinal facies and the fringing Rimthan Shelf carbonates. The major Rimthan Shelf producing carbonates include the Hith, Arab, Hanifa and Dhruma formations. The main structural and depositional factors that control hydrocarbon traps along the Rimthan Shelf are documented by extensive 3D seismic attributes, time slices and horizon slices. Seismic evidence for biohermal carbonate mounds is reviewed, using world-wide biohermal stratigraphic models. The Gotnia Basin and Rimthan Shelf is a sleeping giant for future oil exploration in the Middle East.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece