Integration Of Core And Petrophysical Data To Evaluate The Reservoir Heterogeneities In The Lower Goru Formation, Southern Indus Basin, Pakistan

Abstract

Integrating core and petrophysical data to evaluate reservoir heterogeneities in the Lower Goru Formation of the Southern Indus Basin, Pakistan provides a comprehensive understanding of the formation's complexities. This study aims to identify facies and mineralogical variations within the reservoir, examining how these factors contribute to its heterogeneity and affect reservoir properties. The research seeks to illuminate the interplay between geological characteristics and reservoir quality by correlating core data with petrophysical measurements. Methodologically, this study involved a comprehensive analysis of three cores from basal sands of the Lower Goru Formation, extracted from Wells A, B, and C. The cores were thoroughly logged for sedimentological, lithological, and ichnological features, followed by detailed slab and thin section studies to assess mineralogical composition and textural properties. Core plug samples were subjected to porosity, permeability, and water saturation measurements using advanced techniques. Additionally, gamma-ray logging and well log analysis provided further insights into the formation's petrophysical attributes. The analysis reveals a diverse sedimentary sequence, characterized by very fine to coarse granule-sized sandstones with varying sedimentary structures such as cross laminations and mud-drapes. The facies indicate a shoaling-up sequence from offshore to shoreface environments. Core plug analysis highlights significant reservoir heterogeneity, with variable porosity and permeability, suggesting complex spatial distribution and potential sweet spots for hydrocarbon production. Well-log data corroborate these findings, showing moderate porosity but extremely low permeability and high water saturation, challenging hydrocarbon extraction. In conclusion, the study underscores the Lower Goru Formation's complex reservoir characteristics, marked by significant heterogeneity in facies, mineralogy, and petrophysical properties. The integration of core and well log data highlights the need for tailored recovery strategies to manage the reservoir's tight nature and high water content, aiming to optimize hydrocarbon extraction and improve reservoir management practices