Technical Evaluation of 18.625 × 22 Casing While Drilling Introduction in Jurassic Wells Kuwait Fields

Abstract Deep drilling operations in Kuwait necessitate large-bore well designs to access Jurassic gas reservoirs, each well typically requiring 4-6 months to complete. A key challenge is setting 18.625-in. casing in Zubair while drilling through Shuaiba formation, where severe losses often extends drilling time and escalates AFE costs. This study investigates the feasibility of applying Casing While Drilling (CWD) in the 22-in. section to reduce flat time associated with Shuaiba losses. The evaluation addressed drilling 22-in. hole section between 6,000–11,000 ft TVD and landing the 18.625-in. casing in Zubair formation. Implementing large-diameter Casing While Drilling (CWD) at these depths entails operational risks, necessitating a detailed technical assessment. Key considerations included torque prediction at TD, stab-in cementation using specialized float equipment, centralization and cement standoff analysis, casing connection torque capacity, and PDC bit suitability for the deep interval. This marks the first global attempt to apply CWD with this casing size at such depths. Integrating all risk mitigations and contingencies, a comprehensive execution plan has been finalized and approved. Pilot implementation is scheduled in West or Southeast Kuwait, with the objective of enhancing deep-drilling performance and minimizing non-productive time associated with Shuaiba formation losses.