Unlocking Potential: Innovations in North Oman Carbonate Field Development
Authors: Badi M. S. Al , Huisman S. E. , Hinai M. S. Al , Salmi I. H. Al , Rahbi S. S. Al , Maqbali H. S. , Harthi A. Al 
Published: November 2024

The Upper Shuaiba Clinoforms in northern Oman represent a geologically complex environment characterized by complex carbonate clinoform structures and lateral facies variations. These formations, deposited during the late Aptian regressive cycle, feature prograding carbonate sediments that extend towards the Bab Basin. The stratigraphic architecture of the Upper Shuaiba reservoir is dominated by thin profile clinoforms, typically 1 to 6 meters thick, separated by argillaceous units. This unique depositional pattern intensely influences reservoir properties and hydrocarbon productivity across the region.

Geological studies underscore the significance of understanding lateral facies staggering within the Upper Shuaiba formation for assessing reservoir quality. Research highlights the diversity of rock types, categorized into five major groups (RT-A to RT-E), each with distinct reservoir characteristics. RT-A, RT-B, and RT-C are primary oil-bearing units, whereas RT-D and RT-E exhibit limited hydrocarbon mobility. The Upper Shuaiba B (USB) clinoform, comprising units B1 and B2, represents this variability, with B1 noted for superior reservoir properties compared to the denser B2 unit.

Well placement within the Upper Shuaiba clinoform presents significant challenges due to the thin and variable reservoir thickness. Initial attempts using conventional methods often resulted in suboptimal positioning and variable reservoir performance, highlighting the need for advanced geosteering technologies. The arrival of deep resistivity and azimuthal electromagnetic (EM) tools has developed reservoir management by enabling real-time reservoir characterization during drilling operations. These tools differentiate between hydrocarbon-bearing formations and surrounding shale, facilitating precise well trajectory adjustments to optimize reservoir contact.

Case studies illustrate the transformative impact of advanced geosteering technologies on well placement and reservoir management strategies. Successful applications demonstrate improved reservoir performance and economic viability through enhanced reservoir contact and optimized production rates. Lessons learned from initial drilling experiences emphasize the importance of continuous monitoring, data analysis, and adaptive strategies in mitigating reservoir variability and maximizing recovery efficiency.

Looking forward, future developments in the Upper Shuaiba Clinoforms include plans for multiple well pairs strategically spaced to cover extensive lateral extents. These initiatives aim to maximize reservoir recovery efficiency while minimizing operational risks and costs. The integration of advanced geosteering technologies not only enhances operational workflows but also contributes to sustainable hydrocarbon exploration and production strategies in complex geological environments.

In conclusion, the Upper Shuaiba Clinoforms of northern Oman demonstrate a challenging yet promising geological setting for hydrocarbon exploration and production. Advanced geosteering technologies play a fundamental role in overcoming geological complexities, optimizing well placement, and maximizing reservoir performance. Continued advancements in geosteering tools and techniques are crucial for achieving long-term success in efficiently developing and managing hydrocarbon resources within this complex stratigraphic framework.