Patent ID: 8800666

Claim:
A method for producing a lightweight riser for offshore well drilling, the riser comprising a main tube extending up to a floating support, at least one auxiliary line being arranged parallel to the main tube, the at least one auxiliary line comprising tubular steel sections assembled end to end, each section of the tubular steel sections being connected to an adjacent section of the tubular steel sections by an end part, each end of the tubular steel sections being provided with a female connection, the end part being secured inside the female connection of the end of a section of the tubular steel sections and mounted with a sliding fit in the female connection of the end of another section of the tubular steel sections wherein the ends of the adjacent tubular steel sections are spaced apart by the end part, a seal being arranged between the end part and the section of the tubular steel sections at a level of the sliding fit, wherein the end part is selected to comprise a material having an elastic limit at least 25% higher than the elastic limit of the steel of the tubular steel sections, and the end part and the ends of the tubular steel sections are dimensioned by accounting for the elastic limit of the material so as to reduce an outer section of the end part at the level of the seal.