Identification of the best correlations of permeability anisotropy for Mishrif reservoir in West Qurna/1 oil Field, Southern Iraq

Abstract

At present, reservoir whether isotropy or anisotropy is taking more attention, particularly the difference in (porosity, permeability, and capillary pressure) associated with pore space. These differences are due to the original sediments and thus diagenetic changes. It has been found that common models are insufficient to predict reservoir performance and field management program design. Recovery factor (RF) is the main factor affecting the optimization process for any reservoir that is very sensitive to reservoir heterogeneity and hence an accurate vertical and horizontal permeability (K_v and K_h) distribution is required. A case study is represented in this paper aimed at vertical permeability estimation from horizontal permeability and porosity for Mishrif reservoir in west Qurna/1 oil field southern Iraq. This study has been accomplished by testing five models, harmonic averaging, Kozeny-Carman equation, Zahaf and Tiab, Iheanacho et al., and Fazelalav to determine vertical permeability and comparing the results with core data values. It is found that the models were used showed an accuracy variation between the units of Mishrif reservoir based on Mishrif full diameter cores from 20 wells. Four new correlations are obtained for mA, CRII, mB1, and mB2 units for Mishrif Reservoir in West Qurna/1 oil field. The correlation shows that the permeability is depending on porosity in the mA unit due to the homogeneity and the Mb1 unit has a higher anisotropy than the other units.