Patent ID: 7600569
Filing Date: 2009-10-13
Classification: E21B,F16L

Abstract:
1. A method for installing and connecting by use of a surface vessel a subsea riser between a seabed installation placed on a seabed and a second installation that lies above the seabed installation, the subsea riser having a first end and a second end, the method comprising the following steps in order: a) connecting the first end of the subsea riser to the second installation and connecting the second end of the subsea riser to a cable extending to the surface vessel; b) deploying the subsea riser in a catenary between the second installation and the seabed installation without establishing an initial connection between the second end of the deployed subsea riser and the seabed installation; c) next, guiding the second end of the deployed subsea riser toward the seabed installation by driving the cable and the surface vessel in a first direction along a sea surface or parallel thereto and by extending the subsea riser wherein such that the extending of the subsea riser exerts a restoring force on the second end in a second direction opposite to the first direction; d) connecting the second end of the subsea riser to the seabed installation, while slackening the second end to position the second end to face the seabed installation under the restoring force on the second end and to transfer a load of the restoring force on the second end to the seabed installation; and e) fastening the second end of the subsea riser to the seabed installation utilizing the load of the of the restoring force.