New subsea disconnects approach brings cost and environment benefits

British engineering designers have taken a new approach to subsea emergency breakaway technology, bringing offshore operators cost savings and environmental benefits.

Emergency disconnections most often become necessary when a vessel loses dynamic positioning or the downline hose becomes obstructed, and conventional methods can compromise staff safety, increase costs, and bring the risk of unwanted spillages.

SECC Oil & Gas – a subsidiary of the Self Energising Coupling Company – addresses these issues with the Hot Make Hot Break dry break coupling system, which was patented in 2006 and is now being used for the first time in the North Sea.

Well Ops, one of the Helix group of companies, has incorporated the SECC disconnect system as part of its new subsea intervention lubricator (SIL) package on the Well Enhancer, which recently entered service to provide subsea operators with both open water and riser-based intervention services.

What distinguishes the SECC system is the use of pressure-balanced technology to ensure all connectors remain balanced at any pressure and any depth. This protects subsea equipment by dispensing with guillotines and uncontrolled subsea and surface disconnections in an emergency.

Instead, pressure lines can be quickly disconnected — manually or automatically — under full working pressure, and because the break is 100% dry there is virtually no spillage risk and no hazards posed to personnel.

Reconnection is quick and straightforward, and can be completed at depths of 10,000 ft or greater via ROV without the need to de-pressurise or de-water the high-pressure hose line. This offers significant safety benefits as well as cost savings through both reduced downtime and fewer hours worked.

Key applications for the SECC Hot Make Hot Break system and its range of mid-hose breakaway coupling and connectors include pumping and injection lines, vessel hoses, umbilicals and down lines. Among others are:

  • Intervention
  • Gas and water injection
  • Chemical injection
  • Choke and kill
  • Pipeline Testing
  • Stab connections
  • Hot flow.

Matthew Readman of SECC Oil & Gas, and the inventor of the technology, said:

“It is no longer essential for the reconnection to be made manually as the technology is specifically designed to be operated by ROV and this brings significant savings in vessel costs. The approach is also much safer, meaning fewer personnel are placed at risk during the emergency disconnect process.”

SECC delivers disconnect system to Repsol

Subsea connector specialist SECC Oil & Gas has delivered a “weak link” pipeline disconnect system to Repsol designed to protect subsea infrastructure and the marine environment. The connector system has been customised to meet Repsol’s specific requirements for the Spanish Casablanca field to reduce the risk of pollution should the pipeline be damaged by either trawling or seismic activity. The connector will be permanently installed subsea on the Lubina tie-back.

The SECC weak link, like all its connector products, are full pressure balanced, have a full bore and are fully piggable. It both protects subsea equipment from damage and reduces the risk of an oil spill by separating when a pre-determined load is placed on the connector and then closing each end of the pipe, hose, umbilical, or down line. The preset parting load is customized to be lower than that required to pose a risk to other equipment. The bore self-seals, so avoiding damage and preventing pollution. The system has no pressure separation forces and being mechanical does not rely on hydraulics or electric power means it is extremely reliable.
What further distinguishes the connector is its capability for reconnection under pressure subsea at depths of up to 10,000ft or greater via ROV and without the need to de-pressurise or de-water the line. These operations are performed in an emergency or for scheduled operational connection and disconnection.

The SECC technology will be installed by Technip on the 3.5km pipeline linking the Montanazo D-5 and Lubina-1 wells in a 4.5” flowline a short distance from the Lubina well. The Casablanca field is around 45 kilometres offshore Tarragona and the project is worth a total of €200 million.

Repsol approached SECC Oil & Gas because the Casablanca field is in a highly sensitive area. After seeing the SECC system demonstrated at OTC, Repsol were highly impressed with what it could offer in terms of environmental protection and efficiency. Repsol are a very environmentally aware organisation and are always looking for products that can help them reduce the chances of accidental discharge. .
Using the SECC Breakaway Coupling on this project adds in an extra safeguard not common in the offshore industry.

Justin Marshall of SECC, which is based in Northwich, Cheshire, said:

“We were approached to provide a connector system to address the particular challenges presented by the Casablanca field and have worked closely with Repsol and Technip to ensure we have matched all their key requirements.”