Innovative Geomechanical Approaches to Hydraulic Fracturing and Carbon Capture: A Comprehensive Case Study in Tight Gas Reservoirs of Oman

ABSTRACT: This study explores advancements in hydraulic fracturing and carbon capture utilization (CCU) in the tight gas formations of Oman. By integrating geological, geomechanical, and operational data, this research improves hydraulic fracturing effectiveness and evaluates the feasibility of CCU in depleted reservoirs. Key results include optimized fracture designs tailored for gas extraction and improved models predicting CO2 containment integrity in post-depletion environments. Findings advance Oman's goals of maximizing hydrocarbon recovery while preparing reservoirs for sustainable CO2 storage. 1. INTRODUCTION The extraction of hydrocarbons from tight sandstone formations, especially in Oman, requires cutting-edge hydraulic fracturing techniques and a detailed understanding of geomechanical properties (Economides & Nolte, 2000). The complexity of these reservoirs, influenced by regional tectonics, formation heterogeneity, and reservoir depletion, has prompted the need for advanced modeling to maximize extraction efficiency and prepare for carbon storage (Fjaer et al., 2008). Additionally, with Oman targeting net-zero carbon emissions by 2050, optimizing depleted reservoirs for CCU presents both challenges and opportunities (PDO Report, 2021). This study aims to (1) enhance hydraulic fracturing efficiency in tight gas reservoirs, and (2) assess the geomechanical feasibility of CCU in depleted sections. By coupling geomechanical and geological models, our approach enables effective fracturing, while ensuring long-term containment integrity for CO2 storage. 2. GEOMECHANICAL ANALYSES Several predictive approaches have been formulated to assess depth-dependent variations in minimum horizontal stress (Shmin) within thin, stratified reservoirs, particularly in complex, laminated formations like the Amin reservoirs. These methods primarily utilize well log data coupled with in-situ stress measurements, with diagnostic fracture injection tests (DFITs) commonly serving as a calibration tool. DFITs, a subset of hydraulic fracture (HF) diagnostics frequently used in tight formations, estimate Shmin by analyzing pressure decline post-shut-in, providing crucial insights into local stress regimes. However, the vertical heterogeneity of unconventional reservoirs often restricts the availability of DFIT data across the full stratigraphic column, presenting challenges in capturing complete subsurface stress variations.