How Do Umbilicals Work?

Transferring power, chemicals, communications and more to and from subsea developments, umbilicals are literally the lifeline to subsea trees, manifolds, jumpers, sleds and controls. The connective medium between surface installations and subsea developments, umbilicals can include electrical, hydraulic, chemical injection and fiber optic connections.

Umbilicals are enclosed with an outer ring specially designed for the subsea environment to which it will be deployed. While they must withstand everyday wear and tear, as well as seabed temperatures, Umbilicals are also deployed in ultra-deepwater and HP/HT environments.

Umbilicals connect from the surface facility to the subsea development through an Umbilical Termination Structure (UTS). From the UTS, umbilical services are transported to the various subsea equipment located on the field. Many times umbilical services are "flown" from apparatus to apparatus via a flying lead, which is similar to the common extension cord.

The number of umbilicals used varies by development because each subsea project is unique. Additionally, umbilicals can be single or multiple connections in a single line. For example, umbilicals might just include chemical injection tubes, while others can include telecommunications cables, as well as electrical cables, bundled together and encased in a single line.

Umbilicals that incorporate multiple connections are referred to as integrated umbilicals. While integrating umbilicals can save on development and installation costs, several different umbilicals may still be required for the development.

There are several purposes for subsea umbilicals. Hydraulics are used to activate subsea wells, and some umbilicals pump chemicals into the production stream. Electrical umbilicals connect to subsea control panels and transmit information about temperature, pressure and subsea integrity, as well as electrical power to the subsea equipment. Fiber optic cables can instantly relay information to the surface about what's happening below.

Advances in umbilical technology have allowed companies to offer umbilicals that are integrated with flowlines, as well. In this hybrid form, the flowline is surrounded by electrical umbilicals, and the group is then encased with tubing.