Level-1 Casing-While-Drilling Technology Utilization Across Extended Drilled Open-Hole Sections Reduced Operational Time and Ensured Operations Continuity

Abstract In extended open-hole sections, the industry's typical operational sequence to preserve wellbore cleaning is performing frequent wiper trips to remove ledges/tight sections (example of the frequency is every 2,000 ft drilled) or performing single wiper trip across the entire open-hole. To reduce the operational time and operational risks of tripping in/out of the extended drilled section, level-1 casing-while-drilling (CwD) is utilized to hard ream the casing string across the entire open-hole to section total depth. It also serves to optimize the casing design of different areas to interest by combining multiple trouble zones in one section. To ease running casing through the extended already drilled open-hole, single or several wiper trips are performed clear ledge/obstructions/tight holes if any. After reaching the previous casing, the drill string is run back through the drilled section, reaming through obstructions/tight holes. The drill string is pulled out again to surface. This operational sequence consumes about 2.5-3 days, in addition to the increasing risk of getting the string stuck. All these operational sequences are replaced by the utilization of the Level-1 CwD technology to hard ream the casing string. The operational days and associated extra cost are controlled and reduced. Main challenge in drilling through unconsolidated sand zones in shallow sections, and time-dependent unstable shale zones in deeper sections is inability to secure them without significant rig time delay. Loss circulation zones exist around these problematic zones. When severe to complete loss of circulation is experienced, the complexity of securing the problematic zones increases. The level-I casing-while-drilling (CwD) technology was utilized successfully to hard ream and permanently isolate the problematic zones without nonproductive time. CwD were successfully utilized to hard ream the casing strings to target depth to case-off the severely unstable zones experienced in the offsets. The additional NPT trips were eliminated completely. In addition, the 9-5/8-in casing string hard reaming was performed while incorporating a multistage differential valve (DV) and cemented in two stages. During the job execution, the reaming parameters are constantly monitored to not exceed casing strings limitations, especially the accumulated fatigue on the string as they are rotated. As a result, the troubles experienced in offset wells were successfully managed. Complexity in drilling wells is increasing. Therefore, introducing innovative solutions that enable reducing the number of extra trips, is essential to reducing NPT. The offset wells drilling troubles related to securing unstable formations were studies thoroughly. Level-I CwD technology was successfully utilized to eliminate those identified troubles without adding additional time-delaying trips. The unstable zones were secured in a record time compared to the offsets. The results were reaming the casing through extended open-hole sections until reaching the longest open-hole interval worldwide to be reamed with the 9-5/8-in casing allowing combining and isolating multiple trouble zones together.