Permanent Pipeline Repair Clamp
ROV installable Smart Clamp is a split mechanical/hydraulic fitting used to repair a damaged or leaking subsea pipeline. The fitting eliminates costly pipeline shut downs and expensive hyperbaric welding associated with other repair methods.
The fitting is available in a full structural and non-structural versions that provide pressure containment to the pipeline within the encapsulated area. The non-structural version may be used to repair a pipeline that is structurally sound and has only minor damage such as pinhole leaks, local pipe wall thinning or shallow dents. The full structural version, utilizing a grip and bowl mechanism, replaces structural integrity in more severely damaged pipelines with cracked girth welds, kinks, or punctures.
Diverless Installation
The Diverless Smart Clamp is lowered into position just above the damaged pipeline section that has been lifted off the seabed by the pipe lift frames. First, an ROV intervenes through a hot stab into one hydraulic coupling to pressurize the cylinders in order to open the clamp. The fitting is then lowered until the pipe saddles contact and position on the pipeline. An ROV utilizes the same dual port hot stab and hydraulic coupling to pressurize the cylinders to close the clamp. The body studs are then tightened using an ROV modified hydraulic torque wrench. ROV intervenes through the second hydraulic coupling to simultaneously pressurize the actuator flanges to set the gripping and sealing mechanisms of the clamp. If the damaged pipeline section is not leaking, ROV again intervenes through the second dual port hydraulic coupling to perform an annulus test to verify the sealing integrity of the clamp. All the setting functions are hydraulic and are operated via an ROV panel with API 17D interfaces.
Equipment Required for Installation
Surface support vessel that can lift the clamp and lower it to the seafloor and support ROV operations, work class ROV:
- 100 hp minimum
- capable of maintaining position in the specified currents
- equipped to provide bi-directional hydraulic flow of 4 gpm @ 3000 psig
- equipped with wide-angle and close –up monitoring and recording systems
Catalogue of Smart Clamp – Diverless
