The installation of flowlines in ever deeper and remote areas requires the usage of specific technologiesrnin order to carry out pre-commissioning operations. As the water depth increases, the weight of thernconventional equipment to be deployed to perform the required operations becomes a major issue andrnalternate solutions are thus required. An option lies in using Coiled Tubing. Coiled Tubing consists ofrncontinuous pipe that has been coiled around a reel and can be deployed and recovered according tornoperational needs.rnSo far, offshore operation of coiled tubing has been limited to small diameters and to short operationalrnduration. The pre-commissioning operations can require the Coiled Tubing to be deployed several timesrnfor durations sometimes exceeding a month, and also requires larger diameters (typically 3.5u0002). As thernduration of operations increases, a suitable way of assessing and mitigating the fatigue of Coiled Tubingrnis required. To that extent SAIPEM has carried out an extensive testing campaign aiming at betterrnunderstanding the mechanism underlying plastic and elastic fatigue. Once enough confidence in thernmodels has been gathered, the Coiled Tubing has been deployed offshore for the pre-commissioningrnoperations of several Brazilian projects.rnThis paper reports the lessons learnt from an innovative pre-commissioning method based on CoiledrnTubing that was successfully implemented on four ultra-deep offshore pipelines in 2015. All these projectsrnwere located offshore Brazil in water depth around 2200 m. The paper will provide feedback on thernengineering and operations associated with the use of large diameter Coiled Tubing for precommissioningrnin deep water. A first section will highlight the specificities of the projects whilernsubsequent sections will provide more details on offshore operations.
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