Lithology Investigation of Shaly Sand Reservoir by using Wire Line Data, “Nubian Sandstone” SE Sirt Basin

Identify the rock lithology has important meaning for estimating the reserve of petroleum as reservoir capacity and storage ability. The lithology identification from well log based on not conventional cross plot proposed and studied, which is more easier instead of rock core data observation results. However, this work carried out comparison between chart and analytical solution of matrix parameter (ρma and ΔTma) estimation values of producer shaly sand reservoir, and present the main depositional environment affects. In addition to influences of pyrite, ferruginous encrustations, organic material throughout this studied reservoir. Consequently, variety of matrix parameters values is contributed by clay minerals present in this reservoir type. This study based on wire line data measured over than 750 feet produced Upper Nubian Sandstone belong to two oil fields, SE Sirt Basin. This shaly reservoir divided into three main units (R, E and F), and each unit has been subdivided into three subunits (F3, F2, F1, E3, E2, E1, R3, R2 and R1) from bottom to top according to depositional and petrophysical properties.