DESIGN PROBLEMS AND DEVELOPMENT PROSPECTS FOR ICE-RESISTANT SEMISUBMERSIBLE FLOATING DRILLING UNITS

The work goal consists in identification of advanced trends in development of ice-resistant semisubmersible floating drilling units (SFDU) and elaboration of the new conceptual solution. To reach this goal, the home and foreign experience of design and building of ice-resistant SFDU was analyzed comparatively and progressive technical solutions, which provide year-round operation of units in severe ice conditions and increase of their economical efficiency, were searched for. It was demonstrated that small waterline area, use of two or three simplified underwater pontoons with stabilizing columns, absence of additional (relatively the columns) braces, which cross the waterline, application of inclined columns (or ice-breaking caps), which increase the motion damping and decrease ice loads, application of ice-cutting shape of stabilizing columns and ice teeth in their underwater portions are typical for rational architectural and structural shapes of ice-resistant SFDU. SFDU-trimaran with a turret-type device having increased ice-resistance and ensuring cost decrease for exploratory boring was considered as an innovative solution. Recommendations of the paper serve for increase of ice-resistant SFDU reliability and profitability during Arctic operation.

1. Plavuchiye polupogruzhnyye burovyye ustanovki: istoriya, sovremennost, perspektivy: Analiticheskiy obzor. [Semisubmersible floating drilling units: history, prospects. Analytical review]. St. Petersburg, FGUP “Kryl. gos. nauch. tsentr”, 2014, 212 p. (In Russian).

2. Kryzhevich G. B., Podgornyy L. N., Popov N. G., Shaposhnikov V. M. Analiz konstruktivnogo oblika i materialoyemkosti konstruktsiy ledostoykikh plavuchikh burovykh ustanovok na primerakh sozdaniya krupnotonnazhnykh platform “Polyarnaya Zvezda” i SS-50. [Analysis of the structural layout and materials consumption for structures of ice-resistant floating drilling units as exemplified by developing large-capacity platforms “Poliarnaya zvezda” and СS-50]. Proceedings of International Conference on Naval Architecture and Ocean Engineering, NAOE2016, June 6-8, 2016, St. Petersburg, Russia. (In Russian).

3. Kryzhevich G. B. Novyye konstruktivnyye resheniya dlya ledovogo poyasa stalnykh morskikh sooruzheniy. [New structural solutions for ice belts of steel offshore structures]. Tr. Kryl. gos. nauch. tsentra, 2015, vyp. 86 (370), pp. 133—138. (In Russian).

4. Kryzhevich G. B., Popov N. G. Montazh plavuchikh burovykh ustanovok metodom nadviga na plavu s deformirovaniyem konstruktsiy opornogo osnovaniya. [Assembly of floating drilling units afloat by overthust with deforming the substructure structures]. Nauch.-tekhn. sb. Ros. mor. registra sudokhodstva, 2016, no. 44/45, pp. 32—40. (In Russian).

5. Kryzhevich G. B. Prochnost tolstolistovykh svarnykh konstruktsiy sudov i okeanotekhniki v arkticheskikh usloviyakh. [Strength of plate welded structures of vessels and ocean engineering in Arctic conditions]. Tr. Kryl. gos. nauch. tsentra, 2017, vyp. 2 (380), pp. 32—41. (In Russian).