Optimizing Exploitation Strategies for UAE Unconventional Oil Resources: A Case Study on Integrating Rock Quality & Completion Quality Aspects

Abstract Exploration in the Shilaif formation, one of the unconventional reservoirs in the UAE, is challenging due to its complexities in lithology and its rock mechanics. Shilaif comprises bituminous, dark, fine-grained wackestones to packstones (Al-Zaabi and Taher et al., 2010), which inherently possess high heterogeneity in their petrophysical and geomechanical properties. This heterogeneity significantly complicates the identification of optimal zones for hydrocarbon exploitation, despite the formation's substantial hydrocarbon potential. To address these challenges, a comprehensive, integrated approach is required to delineate the best reservoir intervals based on Reservoir Quality (RQ) and Completion Quality (CQ) metrics. This study leverages various methodologies, including petrography, petrophysical analysis including advanced Magnetic Resonance data, core analysis such as Routine Core Analysis (RCA) and Special Core Analysis (SCAL). Key techniques like Mercury Injection Capillary Pressure (MICP) for pore throat distribution and Self-Organizing Maps (SOM) for rock typing are also included. Additionally, geochemical and detailed geomechanical studies are integrated to identify perforation zones for efficient hydraulic fracturing (hydrofracture) initiation for flowable hydrocarbon evaluation. For this integrated study, a well targeting the unconventional Shilaif was analyzed. Data collection included acquiring conventional core, wireline logs, mud logs, lithocuts etc. All the data corroborated and interpreted to prepare a working model that honors all data acquired through multiple sources/operations. This comprehensive data integration was crucial for the planning and design of hydrofracturing and subsequent well testing operations.