Shallow-water vs deepwater

The following are the main difference between shallow-water and deepwater subsea field developments.

Hardware design

• Shallow-water
  • Because diver-assisted intervention is possible, an ROV–related structure is not necessary.
  • Mudline trees will usually be used.
• Deepwater
  • Because an ROV assists with all interventions, an ROV-related structure is needed.
  • Insulation is needed for flowlines due to high pressures and low temperatures.
  • A horizontal or vertical tree will be used.

Installation requirement

• Shallow-water
  • Limited by the size of vessel.
• Deepwater
  • More difficult than in shallow water due to higher tension, especially horizontal load.

Umbilical design

• Shallow-water
  • Smaller umbilicals can be utilized due to the short distance of power transportation.
• Deepwater
  • Umbilicals are bigger and more expensive.

Intervention,maintenance,and repair

• Shallow-water
  • Diver-assisted intervention is feasible.
• Deepwater
  • Deepwater maintenance and repairs require the use of ROVs for surveys and some repairs.
  • Deepwater subsea developments are high cost and high risk.