Automated managed pressure drilling system successfully drills ‘undrillable’ wells in 2,000 meters of water
CHALLENGE – The operator elected to use managed pressure drilling to overcome these challenges. This project would also be the world’s first implementation of a MPD surface control system onto a MPD ready drill ship. The safe and successful implementation of Halliburton’s GeoBalance® MPD technology required an engineered approach working closely with the operator from the planning phase, through training exercises, and during the job execution.
Halliburton’s solution to these drilling challenges was to deploy GeoBalance automated MPD service. The package deployed was designed for optimal adaptability and real time pressure control throughout all operations. The drilling challenges required a system that was capable of maintaining the bottom hole pressure control within 50 psi window and also be able drill with either a pressurized or floating mud cap.
To accomplish this objective a GeoBalance automated choke along with a 2000 psi Coriolis meter were installed on two 6th generation dynamic positioned ships. GeoBalance then installed and integrated its automated MPD software package with the rigs existing technology. To finalize the preparation Halliburton developed a two tiered comprehensive training program for all parties involved in the operations. The first part of training was a course consisting of two level or degrees of difficulty. Level one exercise was designed as an MPD overview with the goal of exposing all operational personal to the theory of MPD and the equipment that would be utilized on this project. Level two was designed to expose critical personal to the procedures and develop a strong understanding of the contingency procedures.
SOLUTION – As this was the first ever implementation of an MPD control system onto an MPD ready drill ship, the operator decided to use MPD on the 16 inch hole salt section. This allowed all rig crews to become familiar with MPD operations on a live well in a non-hydrocarbon zone.
Training in the salt section provided the competencies to react with proper responses once in the reservoir. The uncertainty of the reservoir pressure created an extremely narrow drilling window which progressive got narrower due to a hydrocarbon gradient.
To keep the well within the available hydraulic window, the MPD design was set slightly above the highest pore pressure in the reservoir with a statically underbalanced drilling fluid. Running speeds were designed to control surge and swab pressures on trips and the automation with the GeoBalance MPD system mitigated their affects in real-time. To understand and correct the well’s hydraulic health status required advanced event detection and the ability for the MPD system to react to these events. On the operator’s wells, Halliburton utilized the DetectEv application which uses well signature patterns for event identification and the MPD system with an appropriate response. On these wells the two events of possible concerns were taking losses and experiencing kicks.
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