A new 30” pipe-line from an offshore field to an onshore Gas Plant was ready for commissioning. During commissioning a pig was propelled through the line with 100bar nitrogen. The ‘hydrocarbon’ gas that was in front of the pig was to pass through an orifice plate into an existing line (at lower pressure). Inevitably this would cause a temperature drop if the flow rate was too high. If the temperature had dropped below -40°C there was a danger of the carbon steel pipes failing.
Method & Objectives
- Measure pressure and temperature both upstream and downstream of an orifice plate installed on the sub-sea manifold.
- Display live pressure and temperature sub-sea for viewing by ROV
- Transmit data to surface via ROV umbilical
- Record pressure and temperature for later analysis