Possible New Hydrocarbon Plays Within the Cretaceous Petroleum System of the Mesopotamian Basin, Central and Southern Iraq

Sadooni, Fadhil N., UAE University, Al-Ain, United Arab Emirates

The accumulation of new geological data from the countries bordering Iraq raises the possibilities for the discovery of new plays or areas of hydrocarbon potential beyond the existing Cretaceous petroleum system of the Mesopotamian Basin.

The new plays include (1) basin-margin carbonate build-ups within the Shu’aiba, Mauddud and Mishrif formations. These plays are already proven or are in production in Saudi Arabia, Qatar and the UAE; though have yet to be identified in Iraq. This is because the technology required to delineate them is unavailable, or because they are located in inacces­sible areas that have experienced severe armed conflicts for the past few decades; (2) strati­graphic traps within the clastic systems of both the Zubair and Nahr Umr formations. Data from Kuwait suggest that these two formations include sediments that were deposited with­in a broad spectrum of depositional environments, ranging from deltaic to shallow marine. Further detailed seismic work may locate hydrocarbon entrapments beyond those structures already identified; (3) the existence of oil in other reservoirs that were previously ignored by the Iraqi exploration program, such as the Sulaiy, Ratawi and Mauddud formations. These latter formations have been found to be oil-bearing in Kuwait and other countries; (4) for­mations in new exploration areas that have been found to contain oil, e.g. the high potential Hartha Formation in the northern extensions of the East Baghdad Field and some parts of western Iraq, and possible hydrocarbon accumulations in the Khasib Formation in some central fields other than East Baghdad (such as the Ahdab and Dhefria); (5) other subtle traps including the possibility of mud mounds in the Yamama Formation, dolomite traps in the Mauddud Formation and fracture-induced entrapment within the Shiranish Formation.