Materials, Welding, and Fabrication for the Jolliet Project

ABSTRACT The Jolliet project fabrications are noteworthy, not only for their unique designs am record setting installations, but also for the novel materials, welding procedure requirements, am construction procedures. 'Ibis paper will discuss the novel aspects and techniques used to construct the major component for the Jolliet am Marquette projects. These components consisted of the templates, the 'TIWP structure, the tendons, the two fixed jackets, am the pipelines. Additionally, experiences with using am welding new generation steels will be presented. Further more, the benefits from requiring am adhering to very specific fabrication am welding procedures will be demonstrated by comparing repair rates for these component. INTRODUCTION The materials, welding am fabrication of the Jolliet am Marquette field development components accounted for over 30% of the two projects' costs. Also, these activities were always on the critical path for installation am the on-time scheduling of the project. since the budget am schedule were significant parts of the project, special requirements were developed, when necessary, to assure that the time am investment in these areas were as trouble-free as possible. 'Ibis is especially critical when construction problems with the Hutton tension leg platform (TLP) were considered. Construction problems with the Hutton tension leg platform were related to welding am hydrogen/cold cracking of susceptible structural steel. 1 These problems were significant since they resulted in a delay of approximately nine months to the project's production of first oil. These problems were not related to the design am application of the novel tension leg platform technology. However, the fabrication problems were significant due to the delays. The problems am recommended solutions discussed in this reference pointed out the need for specific materials, welding, am fabrication requirements to prevent the problems from reoccurring. 'Ibis would apply not only to tension leg type platform construction, but to any structural steel construction. 'These learned lessons were applied during the design, engineering, and construction of the Jolliet am Marquette project components. '!he main components discussed in this paper have 4 described in detail in other papers. " These components are the tension leg well platform ('TIWP) structure, the drilling am foundation templates, the tendons, the Jolliet am Marquette project fixed jackets, and the pipelines/in-field flow lines. This paper will discuss the precautions am special requirements taken to provide for minimum trouble fabrications. 'These trouble-free fabrications were instrumental in the resultant on-time am under budget Jolliet project. Additionally, the novel construction procedures for special components will be detailed. MATERIAL SUMMARY The approximate steel weights associated with the main project components are shown in Tables I, II, am III. 'These tables shown the respective weight breakdown of the components related to the TIWP, the Jolliet central production platform (CPP) jacket, and the jacket for the companion Marquette field development. Additionally, the pipeline steel, which weighed approximately 13,400 tons, are not included in the tables.