Definition
Umbilical refers in the oil and gas industry to the connections used offshore between the subsea equipment and platforms or floating production units and enabling the control from the surface.
The umbilicals are made of steel or thermoplastic to be flexible and in the same time to resist to operating conditions.
Comments
Umbilicals provide control, power, communications and chemical services between a subsea production arrangement and a remote facility floating on surface.
Umbilicals may be used for production control, chemical injection, subsea pumping and processing, gas lift and underground gas storage among others.
Umbilicals are designed in respect with several factors including water depth, function, environmental conditions and temperature.
Umbilicals may have large diameters for gas or chemical or water injections or for gas lift operations
Umbilicals may also carry communications provided via signal cables, fiber optic cables and electrical power transmission for chemical injection lines, corrosion inhibition, and prevention of wax.
With the development of the offshore exploration and production, especially of the deep offshore, the umbilicals are getting longer to reach several kilometers.
In addition more and more equipment are installed on the seabed for safety requirement such as the blowout preventer (BOP) or to facilitate the oil and gas production with water injection pumps, gas booster compressors and all the valves requested around.
All these equipment request more and more electrical power, monitoring and control system which contribute to load the umbilicals with new functions making them larger and larger.
The combined increase of the umbilicals in length and diameter requests the development of new materials to reduce weight and improve the other performances in:
- Flexibility
- Higher pressure
- Resistance to shocks, corrosion, weathering, low temperatures
- Aging
For all these reasons, the umbilicals use more steel than thermoplastic hose, high strength metallic materials and polymers that are resistant to fluid permeation.
Solutions to include high speed optic fibers have also been developed.
From electrical perspective, the umbilicals are now able to transport low voltage and high voltage current with higher insulation systems.
The reliability of the subsea equipment is the must to guaranty the production and safety.
The umbilicals are the critical components to make the subsea equipment running well and lasting.
