Abstract
The Troll field is in the Norwegian sector of North Sea at water depth 300 – 350 m. The field came on stream in 1995 and developed as subsea field. The field has been Norway's biggest oil producer the past five years. The shut-in wellhead pressure is around 140 bar and static temperature 70°C.
The 6 5/8’’ × 5 ½’’ screens were run in 8 ½ horizontal reservoir section in one run to target depth at 6345 m. The length of screen section was 4300 m. The success of this job is considered as the longest screen run in the company because of excellent teamwork between onshore engineering and offshore teams.
To date, all the wells on Troll field over target depth approx. 6200 m were completed with minimum two screen runs which involves extra tubular management, need for service company personnel & equipment for two screen runs.
The planning of this operation required a thorough design of the landing string to run the screens. This included checking previous experiences on the same rig and field to carefully analyze the torque and drag simulations to understand the buckling & weight limitations. It was crucial to use correct friction factor in the simulations and quality control the input parameters which can impact the available weight & buckling. In addition, the downhole data from tripping out of hole with 8 ½’’ drilling BHA prior to run the screens was also utilized to understand the well condition.
