Various embodiments of an umbilical are provided. In one aspect, an umbilical is provided that includes a first tube, a second tube positioned in the first tube and a plurality of third tubes positioned in the first tube. Each of the plurality of third tubes has an inner polymer sleeve and an outer sleeve of carbon fibers in an epoxy matrix positioned around the polymer sleeve. The composite tubes yield a lighter umbilical that is easier to handle than a comparably sized conventional umbilical incorporating steel inner tubing and is more tolerant of dynamic bending and hydrostatic pressure loading.
A composite cable includes at least two flexible resin tubes through which a refrigerant flows, and a plurality of signal lines or a plurality of signal line units including a plurality of signal lines. The plurality of signal lines or the plurality of signal line units is disposed annularly around the resin tubes.
The present inventions relate generally to umbilicals comprising at least one inner tube and at least one composite fiber element to provide greater resistance to radial compressive forces. Such umbilicals may be used in subsea hydrocarbon production applications.