UAEs Unconventional Shale Gas Play Appraisal Technical and Operational Learnings

Abstract The paper presents the technical and operational insights gained throughout the appraisal program, detailing the process from wellbore preparation to production. It explains how intervention tools and practices differed between two wells drilled within the same target, just 500 feet apart. The discussion also covers strategies to maximize operational efficiency, reduce emissions, and leverage local resources, as well as the adaptation and customization of technologies and tools tailored to the UAE's unconventional formations. Multistage well completions have evolved significantly over the last two decades, driven largely by the technological revolution in unconventional shale oil and gas development. Innovations in tools, techniques, and concepts have enabled the efficient exploitation of ultralow-permeability resources on a large scale. However, these methods must be carefully evaluated for early-life fields, where reservoir properties and stress regimes can differ substantially. If not properly designed, hydraulic fracture treatments may be ineffective and jeopardize project outcomes, with implications for national energy self-sufficiency and strategy. The Diyab Reservoir, an organic-rich limestone unconventional play, is located in the Al Dhafra region, about 250 km west of Abu Dhabi. The target formations are characterized by extremely high-stress rock, as well as high-pressure and high-temperature (HPHT) conditions. The appraisal strategy involved completing two horizontal wells on a pad simultaneously (zipper fracturing) with extensive multistage hydraulic fracture treatments using the perf-and-plug method. Both wells underwent long-term flow testing through an early production facility to minimize emissions while gathering critical data to address uncertainties and design a robust field development plan. Several challenges have underscored the importance of multidisciplinary integration and planning, wellbore construction impacts, contractor performance, and tool reliability. This paper summarizes case studies and operational results from the first horizontal well interventions in UAE's HPHT reservoirs, providing important contributions and key insights for achieving UAE's gas self-sufficiency and supporting its energy transition strategy.