Abstract
Ormen Lange is the second-largest gas field in Norway, currently providing 20% of the domestic gas consumption for the UK. As one of the world's largest subsea big-bore gas wells - with production rates up to 350 MMscf/d per well, a 120-km tieback to shore, subzero seabed temperatures and a design life of more than 30 years - these wells provide unique technical challenges. Due to the low reservoir rock strength, high velocities and the life expectancy of these wells, sand control was identified as a prerequisite from day one.
This paper clarifies the logic of the selected sand control method and describes the extensive testing required to qualify the sand control hardware and associated completion fluids for the expected operating conditions. The execution of thirteen successful sand control completion installations will be discussed, including both ends of the success spectrum, and well performance will be covered.
Throughout the four-year installation campaign to date, a number of new technologies were qualified and successfully integrated into the lower completions. These included cableless gauges to provide data closer from the reservoir inflow area, tagged proppant for individual subsea well fingerprinting if proppant is found at the gas plant, and water-tracer technology to aid in identifying the subsea source of potential formation water breakthrough.
This subject explains the extent of the effort to progress an ambitious field development based on big-bore gas wells only (to reduce well count) from the drawing board to flawless execution and world-class production. Relevance also relates to other major big-bore, high-rate gas subsea developments with sand control requirements that are currently being pursued in similar harsh environments (deep water, Arctic conditions, sub-zero seabed) that might have interest in the application of Ormen Lange's successfully implemented technology.
