Operational Insights and Key Lessons Learned from the Drilling Campaign of the First Salt Cavern Underground Oil Storage Project in the Middle East

Abstract This paper presents operational insights and lessons learned from the drilling campaign of the Middle East's first underground salt cavern oil storage project. The operator (Asset Owner) embarked on a pioneering program to develop a strategic crude oil reserve in deep salt caverns, marking the first implementation of this storage method in the region. Drilling these cavern wells required overcoming unique challenges: penetrating a thick Post Hormuz Series (Cap rock) formation in a challenging geological setting, acquiring continuous full-depth core samples for analysis, controlling salt formation behavior (creep and dissolution), and ensuring absolute containment integrity to protect the environment. A comprehensive drilling and coring strategy was employed, including the use of specialised salt-saturated drilling fluids, robust well design with multiple casing barriers, and an extensive coring program that achieved 100% core recovery with a new benchmark in oriented core sector the industry overall. The campaign was completed safely with no major incidents, and all wells were drilled to target depth with gauge wellbores, providing ideal conditions for subsequent cavern leaching operations. Key lessons include the critical importance of thorough pre-project geological analysis, real-time monitoring and adaptive drilling practices in salt, and cross-disciplinary collaboration between drilling, geology and reservoir teams. The successes and learnings from this landmark project not only demonstrate the viability of salt cavern storage in the Middle East but also offer a reference model of best practices for similar projects worldwide. The paper concludes with recommendations to guide future salt cavern drilling campaigns, emphasizing how a human-centric, innovative engineering approach can deliver both performance and safety in challenging new applications.