As more complex oil reservoirs are discovered, innovative flow assurance solutions are required to make the development of new discoveries both technically and economically feasible. Indeed, depending on the size of the field, a long distance tie-back might be relevant to avoid the economic impact of a dedicated production platform. If the tie-back is too long, the water depth too deep and/or the fluid temperature at the wellhead too low, conventional flow assurance solutions might not be applicable. In addition, the size of the reservoir might not justify the installation of a service line or a second production line to generate a loop to allow preservation by mean of flushing the line with dead oil in order to avoid the formation of wax and or hydrates during shutdown. Active heating of the flowlines efficiently covers this gap. Among the available technologies, Heat Tracing appears as being an interesting technology as it features very high efficiency when compared to other solutions. To this date, this solution was limited to reel lay. This paper will present a design suitable for J-laying installation methods thus enabling the technology for larger diameters and remote locations, removing the need for a spool base. This new solution is based on a sliding pipe in pipe concept that has been adapted and improved in order to include a heat tracing capability while optimizing laying rates and offering enhanced monitoring capability including both temperature and stress surveillance. As in any other heat traced pipe in pipe concept, the electrical cables are spirally winded around the inner pipe and, covered with insulating material and enclosed in an outer pipe. Optical fibers are added in order to monitor stress and temperature. In the case of this technology, several innovations aiming at improving the concept have been implemented and tested. The concept mainly relies on a specific connector designed for the simultaneous connection of all electrical wires and fiber optic cables in a single and reliable operation. The concept of sliding pipe in pipe has also been improved, relying on packers and specific pipe end design that simplify the handling of quad joints. The performed qualification testing includes: Full scale fabrication; Testing of the connection system; Testing of the fiber optics; Testing of the packers to validate their holding capacity. All tests have been performed at full scale and included deformation and temperature testing. They allowed to demonstrate that all components can be easily integrated with a conventional Pipe in Pipe design while significantly facilitating offshore operations. The present paper will provide insight on the main features of the technology in addition to details on the performed qualification campaign.

The purpose of this publication is to present the development and qualification of an innovative heat traced flowline concept. Heat Tracing is a relevant solution for long tieback or when relying on a standard or hybrid production loop is not economical or not feasible. This concept is aimed at improving existing solutions and adapting the concept to J-laying installation methods thus allowing for the installation of larger diameters or accessing remote areas where a spooling base is not easily accessible. The developed concept is based on a conventional sliding pipe in pipe configuration that has been adapted and improved in order to include a heat tracing capability while optimizing laying rates. As commonly used in heat traced pipe in pipe concept (e.g. onshore applications), the electrical cables are wound around the inner pipe, covered with insulating material and enclosed in an outer pipe. Fiber optic cables are in general added for temperature monitoring purposes. In the case of this solution, several innovations aimed at improving the overall performance of the system have been implemented and tested. The proposed solution relies on a specific connector that allows for the simultaneous connection of all electrical wires and fiber optics in a single and quick operation. The concept of sliding pipe in pipe has also been improved, relying on packers and specific pipe end design that simplify the handling of quad joints and speed up offshore installation in J-lay. More specifically, the arrangement of the cables allows for an increased level of redundancy and reliability in the system while simplifying its operations. Finally, the pipe not being plastically deformed during installation fiber optics allow for the monitoring of both temperature and stress by the fiber optics. The paper will present: The main features of the concept;The qualification testing performed, including the connection system, fiber optics and packers;A specific focus on the reliability of the system;Details on the monitoring capabilities of the system which allows for improved operability. All tests have been performed at full scale and included pressure, temperature and deformation testing. They allowed for the demonstration that all components can be easily integrated within a conventional Pipe in Pipe design while significantly facilitating offshore operations. The performed tests allowed for validating and qualifying the design that is now ready for its first implementation.