Underwater Structural Repair of HC Platform

The offshore HC Jacket is located in the Heera Field of ONGC Mumbai High at a water depth of 60.10 meter. During inspection the framing level, which is located at EL(-) 06.00 meters of the HC platform, was found to be detached. Dolphin Offshore Enterprises (India) Limited requested NauticAWT to replace the entire frame with a new frame through the application of grouted clamps methodology.

The Scope

• Pre-Engineering; Inspection; In-place; Fatigue; Pushover and FEA analysis
• Supply/provision of grouting material NaX™ Q140
• Supervision of installation of clamps
• Grouting facility; tools and equipment; engineer and grouting crew
• Cubes casting and testing

The Challenges

• Due to the installation of numerous clamps that were all interconnected to form a single structure, grouting of single clamp was not possible, hence all the clamps were grouted in one go.Due to the installation of numerous clamps that were all interconnected to form a single structure, grouting of single clamp was not possible, hence all the clamps were grouted in one go
• Holding all the clamps together from start till finish of the grouting process was a huge task in itself and was made possible by installing the leg clamps one at a time, carefully following the sequence of installation
• The job required intense rigging arrangements in order to hold all the clamps together

The Services

• NauticAWT provided engineering and grouting services for underwater member replacement of Level-C on HC platform using high performance cement NaX™ Q140.

Client Benefit

• The entire level-C, located at (-) 06.00 meters, was replaced with grouted clamps without any underwater welding or shut down of the platform. The entire level-C, located at (-) 06.00 meters, was replaced with grouted clamps without any underwater welding or shut down of the platform
• This structural repair was one of its kind in restoring the jacket strength to allowable margin of operation
• All the deliverables were achieved with high quality performance, client acceptance and satisfaction