No abstract

In the past, the Rotary Steerable System (RSS) had rarely been utilized in PTTEP's Gulf of Thailand well drilling due to poor economic justifications. As the technology becomes mature and thanks to competitive market condition, the risks and the cost to run the system has come down to the level that its benefits and saving can now be reconsidered. With RSS ability to directionally drill while maintaining full string rotation, it is obvious that the target wells to apply this system are those where significant amount of time is required to drill with the mud motor, i.e. deep section where weight transfer becomes problematic. The trials of RSS with Push-the-bit type and Point-the-bit type for performance-drilling had been conducted by starting from the wells and sections that there was significant difference between sliding and rotating rate of penetration (ROP). The application of RSS was then expanded to a more challenging environment in the shallower and softer section. In this paper, the evaluation of RSS performance in fast-drilling environment along with observations of design limitations as well as operational learning curve were discussed. Each RSS type has different restrictions for specific application but through a continuous improvement process, the RSS has proven to be an alternative fit-for-purpose drilling technology for PTTEP to deliver the safest and most economical well.