High resolution stratigraphy and reservoir heterogeneity of Khartam Member of Khuff formation from outcrop, Saudi Arabia

The Permian-Triassic Khuff Formation is the most prolific for natural gas production in the Middle East. Understanding the Khuff reservoir heterogeneity is important to enhance the hydrocarbon production. Integrated study including sedimentology, stratigraphy and digital outcrop modelling is applied here. The studied Upper Khartam Member outcrop is an analog for the Khuff-A reservoir in the subsurface. Ten lithofacies were identified from the whole samples collected from the outcrop. These lithofacies were interpreted to have been deposited in 1) marine transgression, 2) foreshoal, 3) shoal complex, 4) shoal fringes, 5) back shoal, 6) tidal flat and 7) supratidal flat. The composite sequences of the Upper Khartam Member consist of five high frequency sequences. The results of this study also showed a distinct five potential reservoir units in the second and third high frequency sequences. The digital modelling been applied to these sequences to delineate the reservoir units in a more realistic and high precision environment. Outcomes of this study can be utilized to decrease uncertainty on reservoir continuity and architecture and lateral facies continuity within interwell spacing in equivalent Khuff reservoir models in the subsurface. Consequently this might enhance understanding and prediction of reservoir quality in the subsurface.