Casing Reamer Shoe Powered by Positive Displacement Motor Enables Hard Reaming Casing String Through Extended Open-Hole Sections

Abstract In extended open-hole sections, conventional casing deployment often encounters significant challenges, including tight spots, swelling formations, ledges, and accumulated cuttings. These conditions necessitate wiper trips or rotation of the casing string, increasing the risk of casing fatigue, high surface torque, and non-productive time (NPT). To address these issues, a motorized casing reamer shoe powered by a positive displacement motor (CRSPPDM) technology has been developed and utilized to hard ream the casing string. The CRSPPDM delivers localized high-torque, low-speed rotation at the casing shoe level to mechanically ream through obstructions without requiring full-string rotation. This innovative technology has been tested in both laboratory and field settings across challenging wells, demonstrating its ability to maintain flow paths even in the presence of lost circulation material (LCM), deliver torque outputs exceeding 5,200 ft-lbf, and reduce casing drag and deployment time significantly. This manuscript provides a comprehensive overview of the tool's design, operation principles, performance testing, and economic implications of its field deployment in deviated wells. The implementation of the CRSPPDM has improved operational efficiency, lowered casing failure risks, and ensured reliable bottomhole casing placement in extended lateral environments.