AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
A Basin Modeling Approach to Understand the Heavy Oil Occurrence in Burgan Sand of Cretaceous Age, Burgan Field Kuwait
(1) Kuwait Oil comapny, Ahamdi, Kuwait.
At the base of the Burgan oil column (near OOWC) a zone of significantly heavier oil column has been observed in some of the wells. A study was undertaken with respect to the heavy oil occurrence to assess the possible processes that could lead to the formation of heavy oil in the Cretaceous reservoirs of the Burgan and Wara formations. The occurrence of heavy oil in the Greater Burgan Field can be explained by a combination of multiple processes.
The study demonstrated hydrocarbon charging by two possible source rocks. Besides the well known Makhul source, role of Kazhdumi source in charging the reservoir was brought to the fore. The Kazhdumi Formation, a time equivalent of Burgan Formation was deposited in a more distal area of the Dezful Embayment of the Zargos Fold Belt northeast of Kuwait and is a proven, good to excellent source rock in the Iranian Zargos Fold Belt.
The initial charge history causes a special distribution of heavy components in the Greater Burgan Field, which might be the reason for the occurrence of heavy oil mainly in the high permeable layers. As these components are transported in a liquid phase, additional processes are needed to explain the heavy oil distribution. There are strong hints, that water washing, supported by the strong edge water drive, can explain the occurrence of heavy oil in several wells that are positioned in areas of a paleo oil-water contact. Long preservation times of the main accumulations in the Burgan, Magawa and Ahmadi fields are likely to cause gravity segregation within the oil columns of these older accumulations. Biodegradation is believed to have only a limited influence on the heavy oil occurrence.
This study will provide an in depth insight into the heavy oil distribution in the Greater Burgan field , a key element in the future development plan