Depositional Environment to Reservoir Quality Assessment Through Well Log and Sedimentological Analysis of Lower Goru Formation

Abstract This study conducts an extensive sedimentological analysis of the Lower Goru Formation, focusing on core analysis and well log data. The research utilizes data from the Kadanwari well located in middle Indus Basin of Pakistan. The objective is to deduce the depositional environment of the Cretaceous Lower Goru Formation and reservoir quality assessment. Through this analysis, nine distinct lithofacies have been delineated: Massive Sandstone, Bioturbated Sandstone, Parallel Laminated Sandstone, Cross Laminated Sandstone, Massive Mudstone, Sandstone and Mudstone Intercalations, shaly sandstone, Brecciated Sandstone, and shale. These identified lithofacies are categorized into three main facies associations: foreshore, shoreface, and offshore. The findings point towards a depositional setting that transitions from fluvial, to tidal, to deltaic front, and finally to a shallow marine environment. Petrographic examination classifies the Goru Sandstone as primarily subfeldsarenite to sublithicarenite, predominantly laid down in a transitional recycled orogenic setting. Scanning Electron Microscope (SEM) along with EDS assessments of porosity and permeability indicate favorable reservoir qualities. The study concludes that the basal sand units possess superior reservoir properties in comparison to the upper massive sandstone layers.