Abstract: Reservoir Characters of the Ypresian Carbonates, Western Libyan Offshore, Central Mediterranean Sea

Ibrahim Youssef Mriheel

Significant hydrocarbon accumulations have been discovered in Western Libyan offshore in the Ypresian carbonate reservoirs of Jdeir Formation and Jirani Dolomite. The discoveries of hydrocarbons are mainly in structural traps where the Jdeir nummulitic facies and Jirani dolomitic facies B have been structured by salt domes or underlying positive fault blocks.

This study investigates the relationship between environments of deposition, diagenesis and reservoir characters of the two main hydrocarbon producing units of the Jdeir and Jirani formations.

Petrographic and petrophysical studies indicate that porosity in the Jirani Dolomite is related to diagenesis in meteoric environments, while in the Jdeir reservoir is the result of the environment of deposition and diagenesis. Excellent reservoir porosity of Jdeir nummulitic facies and Jirani dolomitic facies B is related to diagenesis in meteoric water during exposure to subaerial conditions which is considered to be due to lowering of sea level and possibly local uplifting.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France