LAUSR

The reservoir character of Cretaceous prolific clastic rocks, widely distributed in different sedimentary basins of Pakistan, is poorly established due to its heterogeneous behavior. In this study, electrofacies classification, principal component analysis, cluster analysis, and petrophysical analysis were performed to establish reservoir character of the Lumshiwal Formation. The electrofacies analysis reveals that the Lumshiwal Formation contains: clean sands with blocky log behavior, shaly sands with intercalated shale beds, sandy shales, and shale. Petrophysical analysis was accomplished by using standard practices with the help of wireline logs of fifteen wells drilled in the study area. After wireline logs and core sample calibration, the Lumshiwal Formation was divided into A, B, and C zones with an effective porosity 5–32% in zone A, 12–17% in zone B, and 13–27% in zone C with high permeability and very low volume of shale. The results revealed that Lumshiwal Formation represents relatively a vertically and laterally heterogeneous sedimentary unit with good quality reservoir facies, which were deposited in shallow marine environment with upward coarsening grain size.