UNDERSTANDING THE DISTRIBUTION OF SATURATION EXPONENT IN THE NUBIAN SANDSTONE FORMATION, SIRT BASIN LIBYA USING GLOBAL HYDRAULIC ELEMENT APPROACH

Abstract

The estimation of hydrocarbon reserve is strongly dependent of electric logs data and the saturation exponent has either assumed or used on average value of the whole of reservoir. The reason of this that the petrophysist dos not usually has a more detailed description of reservoir. The main objective of this study is to use the Global Hydraulic Elements approach to estimating the distribution of saturation exponent in the Lower Cretaceous of Nubian Sandstone Formation Sirt Basin, Libya. Amaefule et al (1993) introduced the first rock typing approach which was strongly dependent on core plug data sets and was successful in determining different systems in a single dataset. But this method has a major limitation when applied many data sets. This limitation has been overcome by the new concept of ‘Petrotyping’ (using Global Hydraulic Elements) which was developed by Corbett et al, 2003; Kooistra, (2004). In this study two wells are selected from Sirt Basin to evaluate reservoir description of Nubian Sandstone Formation using Global Hydraulic Elements. Six samples plugs have been selected from different Global Hydraulic Elements to determine saturation exponent using porous plate method and to distinguish the saturation exponent between the Global Hydraulic Elements in the Lower Cretaceous of Nubian Sandstone Formation, Sirt Basin Libya