WELDING PROBLEMS IN OFFSHORE MOBILE DRILLING UNITS

Offshore mobile drilling units for some time have been classed by the American Bureau of Shipping. These units range in size from small jack up types, 90 ft long by 50 ft wide, to large platform semi-submersible types, 400 ft long by 270 ft wide. The material selected for the various parts of these units ranges over a broad spectrum of both mechanical properties and chemical composition. These factors, together with the complexities of welding joints usually encountered in the support columns, make welding a serious consideration for both design and construction engineers. The welding of joints involving the connection of two or more tabular structures at varied angles requires particular attention. This paper presents some of the welding problems encountered in the fabrication of offshore drilling units, and offers solutions to these problems as they have arisen during the course of survey and construction. In addition, suggestions are presented in the area of weld design in an effort to reduce or eliminate the source of problems prior to actual construction. The goal of both the offshore drilling unit designer and merchant ship designer is in effect the same: to economically produce a structure which will result in satisfactory service experience. To that end, views are also presented on mechanized welding processes recently developed and employed in the shipbuilding industry, and how they may be applicable to the construction of offshore drilling units.

• Supplemental Notes:
  • Presented at 3rd Annual Offshore Technology Conference, Houston, Texas, April 1971.
• Corporate Authors:

  Offshore Technology Conference (1971)

  Houston, TX  United States 
• Authors:
  • Alia, B L
• Publication Date: 1971-4

Media Info

• Features: Figures; References;
• Pagination: 12 p.

Subject/Index Terms

• TRT Terms: Automatic welding; Cracking; Joints; Offshore drilling platforms; Offshore oil industry; Welds
• Uncontrolled Terms: Hot cracking; Welded joints
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00019563
• Record Type: Publication
• Source Agency: American Bureau of Shipping
• Report/Paper Numbers: OTC-1486
• Files: TRIS
• Created Date: Nov 25 1973 12:00AM