Oil, Gas and Petroleum Refinery

Biography

Biography: Ayoub M Abughdiri

Abstract

The pre-upper cretaceous sandstone formation in Sirte Basin, Libya is considered as an important reservoir for hydrocarbon. The main traps system in A-Pool- NC98 block are structural and stratigraphic combination trapes, comprising of at least two major NW-SE trending tectonic blocks, each block is broken by a several more pre-upper-cretaceous faults. The present paper deals with evaluation of petrophysical for four exploration wells A3, A4, A5 and A6 and obtainable sedimentological integration with well A4 of upper Nubian sandstone reservoir occurs at a depth of between 14000-15500 feet, at A-Pool- NC98 block. Generally, the exploratory oil wells which drilled by Waha Oil Company in A-Pool, NC98 block, eastern Sirt Basin, Libya are producing from the upper Nubian sandstone reservoir. The upper Nubian sandstone reservoir is a complex of fine to medium grained, moderately to well cement mainly by silica and ferroan dolomite, grains are angular to rounded with straight, concave-convex and slightly sutured contacts. The geological and petrophysical evaluation have been done by using Techlog and Petrel software in study area taking a read every 0.5 feet and analyzed for detailed evaluation of reservoir parameters. The obtained petrophysical analysis are clearly showed that the upper Nubian sandstone considered as a good reservoir quality in wells A3, A4 and A5, whereas bad reservoir quality in well A6. The hydrocarbon in A-Pool is very rich retrograde condensate gas and waxy oil. The hydrocarbon has been sourced from hybrid petroleum systems (pre-upper cretaceous and upper cretaceous).Three main lithofacies have been recognized in upper Nubian sandstone by core interval; trough cross-bedded, horizontally laminated and low angle cross-bedded sandstones with many minor lithofacies such as rippled and fine laminated sandstones.