Anteo : the Float-over giant

Abstract Anteo is a "giant" hydraulic system providing one of the most reliable and cost-effective solution to the market demand of Integrated Deck installation by float-over method. Anteo made up by the ALS (Actuated Leg System) and the BRS (Barge Release System) designed to allow the mtegrated deck installation in severe environmental conditions such as long/short crested seas up to 2.25 m Hs or swell up to 2.00 m Hs (depending on the periods and headings)... The lowering system is the core of the whole operation and It will be mainly based on hydraulic jacks active action. The deck is loaded out in the fabrication yard on a barge and properly fastened on the "BRS" grillage. The BRS are support assemblies with two hinged bearing plates supporting the deck weight; hydraulic jack are mounted on the top of a sand hopper column. Each deck leg is equipped with a "follower". accommodating two collars (upper and lower) act10g as constraint for the ALS hydraulic jacks. After the barge has been maneuvered inside the jacket slot in the mating configuration, the ALS is activated to mate the jacket leg. By closing the hydraulic circuit, the deck weight will be partially transferred to the jacket leg, eliminating all the relative movements. The ballast system on the barge is activated, meanwhile the jacks on the BRS are raised, jointly with the ALS, in order to disengage the Bearing Plates (the Non-Return Point of the whole operation). By discharging the sand the whole deck load will be transferred to the ALS on the jacket and the barge will be free completing the mating operation. The hydraulic "heart" of Anteo, made up essentially by the hydraulic components are fully recoverable for a subsequent installation, thus guaranteeing a great economical advantage for both the client and the contractor. Anteo will be the "giant" of the offshore industry. 1.0 Foreword The installation of large integrated deck by "mating" (or by ''float-over'') is a "requirement" of the market, especially in the geographical areas of the installation or in its proximately where large HLV or SSCV are not located or easily available. The cases of West Africa and South East Asia are well known: the Cobo installation made by Technip (TPG), the EPKE topside made by Etpm-McDermott and the MLNG-DUA M3PQ-AlMIPQ-A made by Saipem have sent a clear message to the offshore industry. Saipem has been involved in studies for float-over methods since the eighties, Le. in a period whereby the SSCVs available were only owned by the competitors (Heerema, McDermott and Micoperi). Now with the S7000 in the Saipem fleet the float-over methods are seen as an alternative to integrate the installation activities in projects, where the deck weight is higher than 13.000 - 14.000 t. tons or where the SSCV use is not cost-effective for the client. This is in line with Saipem continued commitment to Client's request: provide the most reliable service at the best cost effective price. The Anteo project was conceived by Saipem Engineering department well before the execution of the two float-over undertaken on behalf of Shell Sarawak Berhad (SSB) offshore Sarawak (Borneo, Malaysia).