Flare Tip Replacements
Vertech Offshore AS is a specialized Norwegian offshore service company, which main business is related to replacement of flare tips. The company was established in April 2004, and was then a direct continuation of former offshore divisions in Statnett and Eltel Networks.
Through more than 35 years with construction and maintenance work on powerlines in the norwegian mountains, competence and experience with respect to use of helicopter in different installation work has been developed. In 1991, the technique was taken offshore. A new technique, with use of specialised guide equipment and helicopter, was for the first time used for changing a flare tip. The flare tip was replaced faster and more effective than anyone had seen before.
Today, we have a long reference list of successfully completed projects. More than 400 flare tips have been replaced, all of them using helicopter. Most operations have taken place in the North Sea, but work has also been carried out in other parts of the world, as USA, Canada, Africa, Brazil, the Philippines, Australia, Azerbaijan, Vietnam, UAE and Qatar.
Method
When replacing flare tips, the "long line" flying technique (sometime referred to as "Vertical Reference") is used. The great advantage with this method is that it allows the pilot to fly while looking down, using a bubble window in the helicopter. The pilot allways has a vertical view directly to the the platform and the load he is carrying. The technique involves the use of a 20 meter long lifting strop ensuring the helicopter is operating well above any danger area, and the helicopter downwash is minimized.
Another important factor is the use of customized guide and locking systems. Prior to removing the existing flare tips, all bolts and nuts are removed and special guide and locking devices are installed on each flange. These guides are fastened to the riser flange and have a spring loaded locking mechanism which keep the flare tips in a locked position even if all bolts are removed. For removing the existing flare tip, the locks are manually released by the installers at the flare platform, and the flare tip is lifted away. When installing the new flare tip, the guides are steering the load directly onto the flange and automathically lock the flare tip flange when it is in position.
Typical duration of a flare tip replacement operation will be from 6-10 hours, depending on the type and number of flare tips. This means the time from the installers enter the flare boom until all replacement work is completed.
An operation like described only involves a small group of personnel. Vertech Offshore crew consists of 3-4 mechanical installers and a supervisor. This crew need to be on the installation for 2 days. Helicopter crew (3 persons) arrive on the platform in the morning on the operation day and leave immediately after completion of the work.
Preparation
Prior to all flare tip operations, a detailed operations manual for the work is prepared. The actual time for helicopter flying is only a small part of the work involved in a flare tip repacement project. However, effective flying is dependant on thorough planning from the start. The manual is compiled in cooperation with the client and shall satisfy both the client’s and Vertech’s quality requirements. A description of the operation is given in detail and the manual also includes such as risk analysis, progress schedules and sequence illustrations.
Vertech Offshore will always provide all tools and equipment required for the operation. This includes such as specialized guide equipment, lifting accessories and all kind of hand tools needed for the work up in the flare boom. Tools and equipment are normally brought offshore in 2-3 small aluminium tool boxes, weighing approximately 300 kg each.
Safety
When carrying out all types of helicopter lifting operations like this, safety has highest priority. Safe Job Analysis is an essential task where every aspect of the work is scrutinized. A separate SJA is prepared for the helicopter work. All lifting equipment and manufactured tooling shall of course be certified according to local requirements.
Vertech normally subcontract the helicopter operator for the work. Before subcontracting a helicopter, both the company and the actual pilots shall be quality assured and approved by Vertech helicopter coordinator. Prior to any operation, the long line pilot shall have demonstrated his skills. In Vertech, we have developed our own quality system for approval of pilots. Any helicopter pilot doing work for us shall be approved according to this system.
Over all the years of operating offshore, we have never been involved in any accidents or personnel injuries at all. The combination of experienced personnel in all positions, the specialized equipment and good planning make this method the safest, fastest and most cost effective method of replacing flare tips.