Background
The Waha oilfield is located in Libya, with complex geological conditions. Drilling operations face multiple challenges including losses, water zones, and wellbore instability. The client imposed strict requirements on well construction cycle and drilling cost control.
Challenge
The project required completing all hole sections from 26" surface casing to 9-5/8" intermediate casing in complex formations, while effectively controlling non-productive time (NPT), ensuring wellbore integrity and operational safety, and achieving drilling rate improvement targets.
Solution
Brilliant implemented targeted rate improvement plans for different sections through optimized bit selection and drilling parameters, refined drilling fluid management, and efficient on-site decision-making. Significant ROP improvements were achieved in the 17-1/2" and 12-1/4" sections, while enhanced risk prediction and rapid response under complex conditions ensured continuous and stable operations.
Results
Actual ROP in all sections met or exceeded design targets. The 12-1/4" section achieved an actual ROP of 46 ft/hr, a 31% increase over plan; the 17-1/2" section reached 50 ft/hr, a 39% increase over plan. Project NPT was controlled at just 2.2%, with active operation time accounting for 81%, effectively shortening the well construction cycle and creating significant economic benefits for the client.
