Device For Anchoring A Raceway Mounting Of A Seabed-To-Surface Facility

Patent metadata

Field	Value
Publication number	US-2016115667-A1
Application number	US-201414890863-A
Country	US
Kind code	A1
Filing date	May 12, 2014
Priority date	May 13, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

A device having a rigid structure immersed in a subsurface by floats and anchored to the sea bottom by tension legs, the device suitable for supporting troughs in a bottom-to-surface connection installation, having a plurality of flexible lines extending to the sea bottom, the flexible lines being supported by the troughs, the trough support structured is connected to a base resting on and/or anchored to the bottom of the sea by a plurality of n tension legs tensioned in parallel, by the float, n being not less than six, each of a plurality of p tension legs from the n tension legs, where p is not less than (n−2) being connected at one of its ends to a distance-varying device secured to the base or to the support structure, the distance-varying device suitable for varying the distance between the support structure and the base.

First claim

1 .- 21 . (canceled)

22 . A device comprising a rigid structure held immersed in a subsurface by floats and anchored to the bottom of the sea by tension legs, for the purpose of supporting a plurality of arch-shaped support and guide elements, referred to as “troughs”, in a bottom-to-surface connection installation between a single floating support and the bottom of the sea, the installation having a plurality of flexible lines comprising flexible pipes extending to the bottom of the sea where they are connected to wellheads, to equipment, or to the ends of undersea pipes resting on the sea bottom, said flexible lines being supported respectively by said plurality of troughs, in which device:
said trough support structure is connected to a base resting on and/or anchored to the sea bottom by a plurality of n tension legs tensioned substantially in parallel by said floats, where n is not less than six, each of a plurality of p said tension legs from the n tension legs, where p is not less than n−2, being connected at one of its ends to a distance-varying device, said distance-varying device being connected to said base or to said support structure or being integral with said base or said support structure, the other end of said tension leg being fastened to an attachment point secured to said support structure or respectively to said base, said distance-varying device being suitable for being actuated to vary the distance between its attachment point to said tension leg and said base or said support structure to which it is fastened or connected; and
the top end of said tension leg is fastened at a top attachment point secured to said support structure or respectively to said distance-varying device, the bottom end of said tension leg being fastened at a bottom attachment point secured to said distance-varying device or respectively to said base, said distance-varying device being suitable for:
varying the distance between said top attachment point and said support structure when said distance-varying device is secured to said support structure; or
varying the distance between a said bottom attachment point and said base when said distance-varying device is secured to said base;
wherein said support structure presents a longitudinal shape of substantially rectangular horizontal section, the device having at least six tension legs, each connected to said distance-varying device, and said support structure having at least six top attachment points, with four of the top attachment points defining four corners of a rectangle, the other two top attachment points being arranged inside a circle that circumscribes said rectangle, at or in the vicinity of two long sides of the rectangle, the four corner attachment points being arranged in the proximity of the longitudinal ends of said support structure.

23 . The device according to claim 22 , wherein said other two top attachment points are arranged inside said circle that circumscribes said rectangle, at the transverse middle axis of said rectangle.

24 . The device according to claim 22 , wherein said support structure is supported by at least one incorporated bottom float to which it is fastened.

25 . The device according to claim 22 , wherein said support structure comprises two portions that are hinged to pivot about a pivot axis that is substantially horizontal, suitable for allowing each of said two hinged portions to pivot relative to the other through an angle of −10° to +10 said pivoting being limited by top abutments and bottom abutments of each of said two hinged support structure portions, said two hinged support structure portions being symmetrical about a vertical midplane containing said pivot axis, each of said two hinged portions being connected to said base by at least three said tension legs, of which at least one is connected at one of its ends to a distance-varying device.

26 . The device according to claim 25 , wherein each said hinged portion of said support structure presents a longitudinal shape of substantially rectangular horizontal section, the device having at least six tension legs, each connected to said distance-varying device, and said support structure has at least six top attachment points, each said hinged portion of said support structure comprising at least:
two top attachment points arranged at the longitudinal ends of each said hinged portion that are further from said pivot axis; and one top attachment point arranged closer to said axis of rotation than a said longitudinal end.

27 . The device according to claim 26 , wherein the top attachment points of said first hinged support structure portion are arranged symmetrically to the three top attachment points of the second hinged support structure portion about the substantially vertical plane containing said pivot axis.

28 . The device according to claim 22 , wherein the top end of said tension leg is fastened to a top attachment point secured to said support structure or respectively to said distance-varying device, the bottom end of said tension leg being fastened to a bottom attachment point secured to said distance-varying device or respectively to said base, said distance-varying device being suitable for:
varying the distance between said top attachment point and said support structure when said distance-varying device is secured to said support structure; or varying the distance between a said bottom attachment point and said base when said distance-varying device is secured to said base.

29 . The device according to claim 22 , wherein said top attachment points of said p tension legs are arranged at said support structure and said bottom attachment points of said p tension legs are arranged at said distance-varying devices, said distance-varying devices being secured to said base, and each said distance-varying device serves to vary the distance between said bottom attachment point and said base.

30 . The device according to claim 22 , wherein said tension legs are cables or chains.

31 . The device according to claim 22 , including at least one said distance-varying device comprising an actuator.

32 . The device according to claim 31 , wherein said bottom attachment point is secured to the movable rod of said hydraulic actuator having its actuator cylinder secured to the base.

33 . The device according to claim 31 , wherein said actuator includes a pressure gauge or a pressure sensor at an orifice of the actuator cylinder, and a locking device suitable for locking the rod in position by closing the actuator chamber in a leaktight manner.

34 . The device according to claim 31 , wherein said hydraulic actuator is connected, or is suitable for being connected, to a pressurized fluid feeder unit on board an undersea robot.

35 . The device according to claim 22 , wherein said support structure supports five to twelve arch-shaped troughs having a radius of curvature in the range 1.5 m to 3 m, said support structure having a width lying in the range 3 m to 5 m, and a length lying in the range 10 m to 30 m, and dead weight in air lying in the range 30 t to 50 t, and said support structure has buoyancy incorporated under the troughs so that each said tension leg is subjected to tension lying in the range 0.5 t to 10 t, said tension leg being dimensioned to be suitable for supporting a tension that is two to four times said tension to which it is subjected.

36 . The device according to claim 22 , wherein said support structure is a metal lattice structure extending longitudinally in a horizontal direction.

37 . The device according to claim

Assignees

• Saipem Sa

Inventors

• Pionetti Francois Regis

Classifications

• E21B17/012

  with buoyancy elements (E21B17/015 takes precedence) · CPC title

• E02D27/50

  Anchored foundations · CPC title

• E02D27/10

  Deep foundations · CPC title

• E21B17/01

  Risers · CPC title

• E02B17/02

  placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto · CPC title