Page 382 - Pipelines and Risers
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         Chapter 19



         Use of High Strength Steel



         19.1  Review of Usage of High Strength Steel Linepipes


         19.1.1  Usage of X70 Linepipe
        i)   General
        Grade X70 is now widely used for high pressure transmission lines in many countries. The
        supplier  reference  lists  summarized  in  Table  19.1  provides  94  project  references  for  4
        suppliers.  This  list  is indicative  rather  than  comprehensive,  as  other  manufacturers  have
        supplied this grade of material. A pipeline project installed in July  1997 for BP in the North
        Sea involves the laying of  a grade X70, 24-inch  diameter pipeline with  a wall  thickness of
        25.8 mm.


        A detailed discussion on materials and design of high strength pipeline is given by Bai et a].
        (2000).


        The reference  list also shows only limited subsea use of X70 material, refer to Table  19.2.
        Again, these references are only indicative and not comprehensive.


        ii)   Oman-India Gas Pipeline
        Discovery  of  extensive  natural  gas  reserves in  central  Oman  in  the  late  1980’s and early
         1990’s has  provided  the opportunity  for development of  several  potentially  attractive gas-
        based  energy  ventures.  In  June  1993 a  study  was  initiated  to  establish  the  feasibility  of
        installing a  subsea pipeline  to connect the gas reserves in  Oman  to markets  in India. The
        preliminary route  of  over  1,100 km would provide a  direct  link between  Oman  and India
        across the Arabian Sea with water depths up to 3,500 m.  The Oman-India Gas Pipeline (0-
        IGP) project is currently on hold and design has not progressed past the preliminary stages,
        which is essentially feasibility engineering.
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