Subsea Production Flowlines
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The term of subsea flowlines is used to describe the submarine pipelines carrying oil and gas products from the wellhead to the riser foot; the riser is connected to the processing facilities (for example a platform or an FPSO). The conservation of fluid flow and the ability to restart production as fast as possible is a prime concern for the operation of any hydrocarbon production system.
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| Subsea Flowlines connect a wellhead to a riser system |
For a subsea production system, the flow assurance is generally governed by 2 factors:
- The Overall-Heat-Transfer-Coefficient or OHTC of the system. It represents the heat loss between the effluent contained in the pipeline and the seawater environment (per degree difference between the effluent and seawater temperature and per unit area of flowline internal surface). The unit is W/m²K or BTU/ft²hr-°F.
- The Cooldown Time which is defined as a number of hours that the operator has before having to start up a preservation scheme, for example to replace the hydrate-prone fluids inside the flowlines with inert (“dead”) oil. It is also called the “no-touch” time.
Over the years ITP has specialized in the provision of highly insulated double wall pipeline for oil and gas transportation and has developed a wide range of fit-for-purpose products combining excellent thermal performance (U values between 0.5 and 1W/m²K/0.088 and 0.18BTU/ft²hr-°F), extended cooldown times (up to 2 weeks) and even infinite coodown time with its heat-traced pipeline.