First Oman Implementation of Pressurized Mud-Cap Drilling Improves Drilling Efficiency and Sustainability

Drilling with a gas cap over the Natih formation in Oman often results in excessive flat time. Using the current dynamic fill equipment to deal with kick and loss scenarios leads to extensive nonproductive time on the rig. Managed pressure drilling (MPD) is a well-established drilling technology, and diverse variants exist to suit different requirements. All those variants use the rotating control device (RCD) as a common piece of equipment, but their procedures are different. The pressurized mud-cap drilling (PMCD) technique in the Natih formation replaces the need for traditional dynamic filling technology. The PMCD application enhances the drilling and completion processes by reducing flat time when total downhole losses are experienced. This paper elaborates on PMCD as a proven drilling technique in total loss scenarios when drilling with it for the first time in the Natih formation in Oman. It describes the PMCD process, the associated equipment, and the results of the inaugural application in the Qalah field.