Fabrication and Erection of Jack-Up Drilling Platform Legs of Heat-Treated Steels

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the 42nd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Oct. 1–4, 1967. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. The utilization of newly developed heat treated steels in the legs of jack-up drilling platforms required the development of new welding and quality control techniques for both shop and field applications. The necessity of these techniques, their development and subsequent application is described. Introduction Early in 1964 it became apparent that the offshore drilling industry had entered an era in which contractors, through the stimulation and requirements of the offshore operators, would be called upon to construct several offshore rigs with an operating depth capability of 200 to 300 feet. One of the major new areas opened to exploration at this time, thus creating an immediate rig demand, was the North Sea. The immediate initiation of new rig construction in the U.K. was the path chosen by The offshore Company as the most expeditious and economical way to meet the need for rigs in this area. The rush to the North Sea had commenced, and it was incumbent on the contractor to construct (offshore rigs as soon as possible with all the modern refinements and suitable for the intended area of operation— in an area of the world where rig construction experience was practically non-existent. As the legs of a self-elevating drilling platform are the most important single structural component, the necessity of rigorous fabrication controls is of vital importance. utilization of newly developed heat treated steels in the legs not only increased the magnitude of fabrication controls, but created the need for development of new welding and quality control techniques for both shop fabrication and field erection applications.