PETRONAS Carigali, as one of the major deepwater operators in Malaysia worked closely with the service providers to develop a series of procedures that ensures the success of two planned wells in the perspective of improving drilling efficiency and minimizing potential drilling hazard. These procedures included employing advanced technology in bottom hole assembly (BHA) design for drilling systems as well as the acquisition and monitoring of both real-time formation logging information and downhole drilling dynamics measurements.

This paper starts with sharing the result of drilling efficiency improvement comparing Jet-In and Drill-Ahead BHA using Mud Motor versus Rotary Steerable System (RSS). Secondly, we demonstrate the applications of downhole multiple-sensor- dynamics measurements which enable drilling optimization in real-time. Lastly, the utilization of formation pressure measurement while drilling to monitor and optimize the mud weight system in real-time for drilling efficiency enhancement as well as potential drilling hazard mitigation.

The RSS Jet-In and Drill-Ahead BHA achieved 83% improvement in Rate Of Penetration compared to the Mud Motor BHA. It also improved the well vertically from +/‒3° to less than 1°. The downhole drilling dynamics tool helped the driller to optimize the drilling process especially in the harsh drilling interval and confirmed the premature failure of the Hole Enlargement Device. The real-time data acquired from the formation pressure measurement sub helped the drilling team to make prompt decision on the mud program. The mud weight was reduced from 9.6 lb/gal to 9.2 lb/gal, which avoided fracturing the formation and reduced the operational cost.

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