The situation
A 38-inch gas pipeline was resting on sleepers where surrounding structures were degrading. Inspection revealed wear and damage that could lead to future leakage in the flange connection.
The consequences of failure were significant: unpredictable downtime, major production loss and potentially long-term shutdown.
Standard solutions were insufficient. Full replacement of subsea structures would be extremely costly and time-consuming, while conventional clamps could expose carbon steel to sour service and introduce new material challenges.
The project therefore required a specialised repair approach that could preserve the existing flange connection and restore integrity without extensive replacement work.
The Solution
Concept
IK Subsea developed a split repair clamp with sealant injection, designed to seal directly at the flange gasket interface while maintaining the original functionality of the flange connection.
Engineering highlights
- Split clamp design for subsea installation.
- Sealing down to the true sealing interface at the gasket.
- Integrated sealant injection system.
- Replaceable inserts for different flange geometries.
- Structural design that relieves bolt loads and takes over flange bolt functionality.
- Internal lining for sour service compatibility.
- DNV-verified design.
- Well suited for CRA pipelines and demanding subsea service conditions.
Delivery & execution
- IK Subsea delivered a complete repair solution and equipment package.
- The scope included the clamp solution, sealing features, structural integration and supporting documentation.
- The solution was planned for subsea installation by divers.
- The end customer was QatarEnergy and the marine contractor was Saipem.
- The clamp was established as a contingency solution at the time of interview.
Verification and qualification
- Design verified by DNV.
- Comprehensive documentation package provided.
- Testing was ongoing at the time of interview.
- One clamp was fully completed; the second clamp was scheduled for testing.
- Verification was a central part of the delivery.
Key Facts
| IK Group company | IK Subsea |
|---|---|
| Segment | Subsea / Pipeline repair and intervention |
| Location | Middle East |
| Year | 2026 |
| Asset type | 38-inch subsea gas pipeline / flange connection |
| Design life | 35 years |
| Delivery model | Subsea intervention with specialised repair equipment |
| Depth / Pressure / Temp | 65 m water depth; design pressure 182 bar; 0-104 C operating temperature |
| Delivery model | Contingency tool for lifting and repair |
| Marine contractor | Saipem |
| End customer / operator | QatarEnergy |
| Status | Contingency solution |
Challenges
38-inch gas pipeline with wear and damage around a subsea flange connection.
Risk of future leakage, unplanned downtime and major production loss.
High pressure and large loads.
Sour, corrosive service environment requiring careful material selection.
Complex flange geometry and sealing requirements at the actual gasket interface.
Need to preserve the functionality of the existing flange connection.
Strict documentation, verification and client specification requirements.
Very short delivery timeline.
Installation in a constrained subsea environment.
Results
Integrity secured for critical subsea infrastructure
The repair clamp helped secure the integrity of a critical subsea gas pipeline connection.
Existing flange functionality maintained
The solution was designed to take over the functionality of the flange bolts while sealing down to the true gasket interface.
Reduced leakage and downtime risk
The clamp reduced the risk of gas leakage, unplanned downtime and related operational consequences.
Full replacement avoided
The customer could avoid a full subsea module replacement and the cost and complexity associated with that scope.
Potentially significant downtime avoided
The contingency solution could help avoid downtime of up to one year.
Suitable for demanding service
The internal lining and sealing concept made the solution suitable for sour service and CRA pipeline conditions.
