公开(公告)号：US09976363B2

公开(公告)日：2018-05-22

申请号：US15037913

申请日：2013-11-20

申请人： STATOIL PETROLEUM AS

发明人： Steinar Kristoffersen ,  Øyvind Haug ,  Guillaume Gravey

IPC分类号： E21B19/00 ,  E21B17/01 ,  H02G1/10 ,  E21B19/22

CPC分类号： E21B19/004 ,  E21B17/012 ,  E21B17/015 ,  E21B19/002 ,  E21B19/22 ,  E21B43/0107 ,  H02G1/10

摘要： A method of installing a flexible line between an offshore platform and a subsea structure and a method of removing a flexible line deployed between an offshore platform and a subsea structure. The method of installing includes at least partially deploying the line in the water using an installation vessel located outside of an exclusion zone in the vicinity of the platform, including lowering a topside end of the line either to the seabed or to an intermediate location between the seabed and the platform. The method further includes pulling the topside end to a position within the exclusion zone and winching the topside end up to the platform, and coupling the topside end to the platform. The method of removing includes decoupling a topside end of the riser from the platform, lowering the topside end from the platform and pulling the topside end to a position outside of an exclusion zone in the vicinity of the platform, and at least partially removing the line from the water using an installation vessel located outside of the exclusion zone, including raising the topside end of the line onto the installation vessel either from the seabed or from an intermediate location between the seabed and the platform.

公开(公告)号：US10119371B2

公开(公告)日：2018-11-06

申请号：US15319677

申请日：2014-06-18

申请人： STATOIL PETROLEUM AS

发明人： Steinar Kristoffersen ,  Guillaume Gravey ,  Øyvind Haug

IPC分类号： E21B19/22 ,  E21B17/01 ,  E21B43/01 ,  E21B43/013 ,  E21B19/00

摘要： A method of removing a flexible line deployed between an offshore platform and a subsea structure, where the platform has a landing deck on which the flexible line is installed, the landing deck facing away from the platform towards an installation side. The method comprises: decoupling a topside end of the flexible line from the landing deck; lowering the topside end from the landing deck to the sea bed using a platform mounted winch, and detaching the winch from the topside end; moving the platform in a direction away from the installation side and positioning an installation vessel on the installation side; lowering a recovery line from the installation vessel and attaching an end of the recovery line to the topside or subsea end of the riser; raising the attached topside or subsea end onto the installation vessel from the seabed using the recovery line; and recovering the flexible line onto the installation vessel, whereupon the platform can be moved back to an operating position.