METHOD AND APPARATUS FOR WORKING WITH OFFSHORE PIPELINES

• US 3,796,058 A
• Filed: 03/09/1973
• Issued: 03/12/1974
• Est. Priority Date: 03/09/1973
• Status: Expired due to Term

• Current Assignee: Jerry J. Jones, Joe C. Lochridge
• Original Assignee: Jerry J. Jones, Joe C. Lochridge
• Inventors: Jones, Jerry J., Lochridge, Joe C.
• Primary Examiner(s): Shapiro, Jacob
• Application Number:
  US05/339,964
• Time in Patent Office: 368 Days
• Field of Search: 61/72.3,72.1,72.4 235/150.27 114/144,.5,235,195,226
• US Class Current: 405/157
• CPC Class Codes: B63B 35/03 Pipe-laying vessels laying pipes under water F16L1/12
• CPC Class Codes: B63B 51/00 Marking of navigation route
• CPC Class Codes: B63H 25/00 Steering; Slowing-down otherwise than by use of propulsive elements using movably-installed outboard propulsion units B63H20/00; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements

Abstract

A technique and apparatus for laying offshore pipelines wherein the manipulating of a pipeline is controlled in response to visually observed relationships between a preplotted pipeline route and the plotted actual position of a pipeline lay barge.

Claims

1. A method of laying a pipeline offshore, said method comprising:

providing pipeline working vessel means operable to lay a pipeline at an offshore location;

supporting a pipeline from said piepline working vessel means with a portion thereof extending between said vessel means and a submerged location;

generating electrical signals representative of the ranges from said pipeline working vessel means to each of a plurality of transponders, each located at a predetermined geographical position;

providing position plotting means carried by said pipeline working vessel means and containing a preplotted course related to a predetermined position of said pipeline;

determining, on said pipeline working vessel means, an actual offshore position of said pipeline working vessel means during the laying of said pipeline;

said determining of an actual offshore position of said pipeline working vessel means being effected by providing means on said pipeline working vessel means for storing data, modifying said generated electrical signals on said pipeline working vessel means responsively to said stored data to correct for inaccuracy related to atmospheric conditions, further modifying said generated electrical signals on said pipeline working vessel means responsively to said stored data to provide electrical signals representative of the ranges, in a predetermined reference plane, from the vessel means to each of said plurality of said transponders, and on said pipeline working vessel means, determining the navigational coordinates of an actual position of said pipeline working vessel means responsively to said further modified generated electrical signals;

visually indicating on said plotting means an indication of said predetermined position of said pipeline relative to an actual position of said pipeline working vessel means as determined by said navigational coordinates;

laying said pipeline from said pipeline working vessel means, with said pipeline working vessel means floating on a body of water and with at least a portion of said pipeline being disposed on said submerged location;

while laying said pipeline from said pipeline working vessel means, operating said pipeline working vessel means in accordance with said visual indication of said predetermined position of said pipeline relative to said actual portion of said pipeline working vessel means so as to cause the location of said pipeline, as laid, to tend to bear a desired coincidence with said predetermined pipeline position.

2. A method of working with a pipeline offshore, said method comprising:

providing pipeline working vessel means operable to work with an at least partially submerged pipeline at an offshore location;

providing a pipeline disposed at least in part at a submerged location;

generating electrical signals representative of the ranges from said pipeline working vessel means to each of a plurality of predetermined geographical positions;

providing position plotting means carried by said pipeline working vessel means and containing a preplotted course related to a predetermined position of said pipeline;

determining, on said pipeline working vessel means, and in response to said signals, an actual offshore position of said pipeline working vessel means during the performing of work relating to said pipeline;

visually indicating on said plotting means an indication of said predetermined position of said pipeline relative to said actual offshore position of said pipeline working vessel means;

performing work on said pipeline from said pipeline working vessel means, with said pipeline working vessel means floating on a body of water and with at least a portion of said pipeline being disposed on said submerged location; and

while performing work on said pipeline from said pipeline working vessel means, operating said pipeline working vessel means in accordance with said visual indication of said predetermined position of said pipeline relative to said actual position of said pipeline working vessel means so as to cause the actual location of said pipeline working vessel means to tend to bear a desired coincidence with said predetermined pipeline position.

3. A method as described in claim 2 wherein said preplotted course is provided by:

providing movable chart means in said plotter means, with said chart means having a desired course preplotted thereon in the form of a plurality of substantially contiguous line segments of a desired offshore course of vessel means, said course line segments being disposed in sequence along a portion of said chart means, and a plurality of segments of grid lines separately oriented relative to at least some of said course line segments. at least one of said grid line segments being associated with at least one of said desired course line segments and being oriented in an orientation relative to said chart means different from that of another adjacent one of said grid line segments, with said different orientations of said one and other grid line segments being operable to reduce with width of said portion of said chart means having preplotted thereon said one course line segment and another course line segment associated with said other grid line segment;

effecting said different orientations by orienting grid line segments associated with at least two adjacent course line segments in relative inclination, with the grid line pattern of one grid line segment associated with one of said at least two adjacent course line segments being inclined relative to the grid line pattern of another grid line segment associated with another of said at least two adjacent course line segments and being displaced from alignment with a projection of the grid line pattern of said other grid line segment;

said relative inclination between said two adjacent grid line segments resulting from different orientations of said one and said otHer grid line segments produced by rotation of one of said one and other grid line segments relative to a projection of the other of said one and other grid line segments; and

arranging the course line segments of said at least two adjacent course line segments in generally end-to-end relation, extending between lateral boundaries separated by a distance less than a distance between lateral boundaries of said at least two course line segments which would result if said at least two course line segments were plotted on a grid pattern comprising said one grid line segment and a projection thereof;

with said lesser distance between said lateral boundaries being a consequence of said relative inclination of grid line segments associated with said at least two course line segments; and

said preplotted desired course, including said at least two course line segments, more closely approaching a generally straight line configuration than would result from the plotting of said at least two course line segments on a grid line pattern corresponding to that of said one grid line segment and a projection thereof.

4. Apparatus for laying a pipeline offshore, said apparatus comprising:

pipeline working vessel means operable to lay a pipeline at an offshore location;

a pipeline;

support means on said working vessel means supporting said pipeline with a portion thereof extending between said working vessel means and a submerged location;

a plurality of remote transponders each having a known geographical location and adapted to transmit radio signals at predetermined microwave frequencies when triggered;

position plotting means carried by said pipeline working vessel means and containing a preplotted course related to a predetermined position of said pipeline;

pipeline working position determining means located on said pipeline working vessel means, and operable to determine an actual offshore position of said pipeline working vessel means during the laying of said pipeline;

said pipeline working position determining means including transmitter means for triggering each of said remote transponders at predetermined time intervals, receiver means for receiving the signals transmitted by said transponders, computer means including first means responsive to said transmitter means and receiver means for computing the ranges from the barge to each of said transponders, means for storing data, said computer means including second means responsive to said data storing means and said first means to said computer means for computing the coordinates of an actual position of said barge in a predetermined navigational coordinate system, said second means of said computer means including atmosphere correction means responsive to said first means of said computer means and said data storing means for correcting the ranges to each of said transponders for inaccuracy related to the refractivity of the atmosphere, and reference plane correction means responsive to said atmosphere correction means and said data storing means for correcting the ranges to each of said transponders to a predetermined reference plane;

visual indicating means included in said plotting means and operable to visually indicate said predetermined position of said pipeline relative to an actual position of said pipeline working vessel means as determined by said pipeline working position determining means;

pipeline laying means comprising said pipeline working vessel means and said support means, with said pipeline working vessel means floating on a body of water and with at least a portion of said pipeline being disposed on said submerged location; and

means operable, while laying said pipeline with said pipeline working means, to operate said pipeline working vessel means in accordance with said visual indication of said predetermined position of said pipeline relative to said actual position of said pipeline working vessel means sO as to cause the location of said pipeline, as laid, to tend to bear a desired coincidence with said predetermined pipeline position.

5. Apparatus for working with a pipeline offshore, said apparatus comprising:

pipeline working vessel means operable to work with an at least partially submerged pipeline at an offshore location;

a pipeline disposed at least in part at a submerged location;

plurality of means at predetermined geographical locations adapted to transmit electrical signals;

position plotting means carried by said pipeline working vessel means and containing a preplotted course related to a predetermined position of said pipeline;

pipeline working position determining means located on said pipeline working vessel means, and operable in response to said signals to determine an actual offshore position of said pipeline working vessel means during the performing of work relating to said pipeline;

visual indicating means included in said plotting means and operable to visually indicate said predetermined position of said pipeline relative to an actual position of said pipeline working vessel means;

pipeline working means comprising said pipeline working vessel means for performing work on said pipeline, with said pipeline working vessel means floating on a body of water; and

means operable, while performing work on said pipeline with said pipeline working means, to operate said pipeline working vessel means in accordance with said visual indication of said predetermined position of said pipeline relative to said actual position of said pipeline working vessel means so as to cause the actual location of said pipeline working vessel means to tend to bear a desired coincidence with said predetermined pipeline position.

6. Apparatus as described in claim 5 wherein said preplotted course comprises:

movable chart means included in said plotter means and having a desired course preplotted thereon in the form of a plurality of substantially contiguous line segments of a desired offshore course of vessel means, said course line segments being disposed in sequence along a portion of said chart means, and a plurality of segments of grid lines separately oriented relative to at least some of said course line segments, at least one of said grid line segments being associated with at least one of said desired course line segments and being oriented in an orientation relative to said chart means different from that of another adjacent one of said grid line segments, with said different orientations of said one and other grid line segments being operable to reduce the width of said portion of said chart means having preplotted thereon said one course line segment and another course line segment associated with said other grid line segment;

said two adjacent grid line segments being associated with at least two adjacent course line segments and being mutually inclined, with the grid line pattern of one grid line segment associated with one of said at least two adjacent course line segments being inclined relative to the grid line pattern of another grid line segment associated with another of said at least two adjacent course line segments and being displaced from alignment with a projection of the grid line pattern of said other grid line segment;

said relative inclination between said two adjacent grid line segments resulting from different orientations of said one and said other grid line segments produced by rotation of one of said one and other grid line segments relative to a projection of the other of said one and other grid line segments;

the course line segments of said at least two adjacent course line segments being arranged in generally end-to-end relation and extending between lateral boundaries separated by a distance less than a distance between lateral boundaries of said at least two course line segments which would result if said at least two course line segments were plotted on a grid pattern comprising said one grid line segment and a projection thereof;

said lesser distance between said lateral boundaries being a consequence of said relative inclination of grid line segments associated with said at least two course line segments; and

said preplotted desired course, including said at least two course line segments, more closely approaching a generally straight line configuration than would result from the plotting of said at least two course line segments on a grid line pattern corresponding to that of said grid line segment and a projection thereof.