Flare Tip Replacement Support

Introduction

Due to reaching the end of its service life, the flare tip at this offshore platform in Malaysia required replacement. This replacement work was to be carried out during a short 6 day shutdown window in October 2020. Thunder Cranes was approached by the client to provide a proposed lifting solution to assist in dismantling the old flare tip and installation of the new flare tip.

Thunder Cranes’ scope of work was to perform the lifting of the old flare tip from the flare deck to a supply vessel, and subsequently the lifting of the new flare tip from supply vessel to flare deck for installation. Both the HP (high pressure) and the LP (low pressure) flare tips were replaced. The heaviest component being 858Kg.

No site visit in advance of the replacement work was possible due to circumstances beyond our control. However, based on detailed drawings and images provided by the client Thunder Cranes was able to provide a detailed engineering assessment, feasibility study, and method statement to show how we intended to carry out the job. These were presented to the client and provided the client with the confidence that the replacement of the flare tip would be carried out successfully.

Challenges

All offshore projects involve challenging circumstances, however this project in particular had more challenges than usual, especially in the year 2020 with the Covid19 protocols and restrictions.

• We only had 1 month for equipment preparation including engineering, fabrication, commissioning, testing, and shipping.
• Tight shutdown window with 6 days to complete the job and any delay would have a great impact on client production.
• Due to circumstances beyond our control the project had to be planned and executed without any site visits and solely based on drawings and pictures provided.
• Due to offshore accommodation constraints, only 2 crew from Thunder Cranes were permitted to perform the job with the assistance of 4 crew from the client. This was an additional challenge for our superintendent and operator to manage man power and familiarisation to the equipment used.
• The flare tip is located at 52 metres above the sea level with limited space for equipment as well as challenging access route to the flare tip deck.

Method

To carry out the task Thunder Cranes designed a modular lifting solution – the TCLF (Lifting Frame). Design specifically for flare tip change-outs, the TCLF is a portable and modular lifting frame that can be installed on the flare deck itself, with a lift line connected to a TC Winch installed on platform deck below the flare tip platform. The TC Winch itself is powered by an independent hydraulic power pack also supplied by Thunder Cranes. A summary of the method employed:

• The lifting equipment arrived at the platform by supply boat, was lifted to the platform loading/lay down area by the platform crane, then skidded into position on the platform adjacent to the flare bridge connecting the platform with the flare tip tower.
• Powerpack and control panel are installed. The winch is welded into position with NDT completed. We then proceeded to install a temporary lifting system for transferring components of the TCLF up to the flare tip deck.
• The flare tip deck is prepared for the installation of the TCLF. Once the components of the TCLF are assembled and securely welded down on the flare tip deck we proceeded with load test of the system using dead weights, with NDT examination before and after the load test.
• The high-pressure flare tip was then detached from its fastenings and lifted over the edge of the flare tip platform, before it was lowered to the supply vessel. This process was repeated for the low-pressure flare tip. The reverse steps are taken to lift and install the replacement flare tip components from supply vessel to flare tip deck.
• Once the installation was completed we proceeded with the removal of the TCLF from the flare tip deck – in the reverse procedure of the erection of the TCLF. Rig down, packing and removal of all TC lifting equipment was subsequently completed and equipment returned to shore via supply vessel.