A new processing for improving permeability prediction of hydraulic flow units, Nubian Sandstone, Eastern Desert, Egypt

Abstract

Abstract Fifteen surface sandstone samples of Late Cretaceous age were compiled from Wadi Kareem area in Eastern Desert, Egypt. Samples were subjected to permeability and porosity measurements to show their distributions and possibility of separating them into different hydraulic flow units. It is known that hydraulic flow unit is a volume of rock within a reservoir that has petrophysical and lithological attributes that affect flow properties and differ from those of surrounding units. It was found out that the normal application of Amaefuleʼs hydraulic flow unit approach using the relation of normalized porosity index (ϕ Z) versus reservoir quality index (RQI) and FZI values at (ϕ Z) = 1 leads to deviation of predicted permeability from the measured one in case of scattered data of (ϕ Z-RQI) relation having a unit slope trend line. In the present study, the additional new processing leads to close matching between the measured and predicted permeability, hence reservoir description improvement. This is simply done through differentiation of all samples that lie on the unit slope trend line and those lie scattered on both sides of it, into three sub-flow units regardless their slopes and the use of (FZI) arithmetic average for each sub-unit instead of that at (ϕ Z) = 1. Permeability prediction has been improved after applying the new additional processing. Capillary pressure-derived parameters for some selected samples as micropores, mesopores, and macropores, used to support the new concept .

Keywords

• New processing
• Permeability
• Prediction
• Flow units