US3751932A — Recovery and repair of offshore pipelines

Claim 1

Independent Claim 111 words

A method for recovering the end of a submerged pipeline from the bottom of a body of water which comprises inserting a pigging element into said end of said pipeline, injecting a gas into the end of the pipeline behind said pigging element while preventing the escape of substantial quantities of gas from the pipeline into the surrounding water, continuing the injection of said gas until said pigging element has been displaced by the gas through a section of the pipeline sufficiently long to extend at least to the surface of said body of water, and thereafter lifting said end of said pipeline to said surface of said body of water.

Claim 2

Independent Claim 111 words

A method for recovering the end of a submerged pipeline from the bottom of a body of water which comprises inserting a pigging element into said end of said pipeline, injecting a gas into the end of the pipeline behind said pigging element while preventing the escape of substantial quantities of gas from the pipeline into the surrounding water, continuing the injection of said gas until said pigging element has been displaced by the gas through a section of the pipeline sufficiently long to extend at least to the surface of said body of water, and thereafter lifting said end of said pipeline to said surface of said body of water.

Claim 3

Dependent Claim 52 words

A method as defined by claim 1 wherein said pipeline includes a check valve which prevents the backflow of liquids displaced by said pigging element and said gas is injected until said pigging element has displaced substantially all liquids from the portion of the pipeline between said check valve and said end.

Claim 4

Dependent Claim 39 words

A method as defined by claim 1 wherein said pipeline is open to the atmosphere at a point remote from said end and said gas is injected until said pigging element has displaced substantially all liquids from the pipeline.

Claim 5

Dependent Claim 12 words

A method as defined by claim 1 wherein said gas is air.

Claim 6

Dependent Claim 32 words

A method as defined by claim 1 wherein said pipeline includes an outer cement coating and said coating is removed from about said end prior to the insertion of said pigging element.

Claim 7

Dependent Claim 30 words

A method as defined by claim 1 wherein said gas is injected through a line extending from a floating vessel moored near said end to said end of said pipeline.

Claim 8

Dependent Claim 40 words

A method as defined by claim 1 wherein said end of said pipeline is formed by cutting off a damaged portion of the pipeline on the bottom of said body of water prior to the insertion of said pigging element.

Claim 9

Dependent Claim 15 words

A method as defined by claim 1 wherein said pigging element is a pigging sphere.

Claim 10

Dependent Claim 47 words

A method as defined by claim 1 wherein an additional section of pipe is connected to said pipeline after said end has been lifted to the surface of said body of water and said pipeline is thereafter lowered back to the bottom of said body of water.

Claim 11

Dependent Claim 45 words

A method as defined by claim 1 wherein a full-opening valve is connected to said pipline after said end has been lifted to the surface of said body of water and said pipeline is thereafter lowered back to the bottom of said body of water.

Claim 12

Dependent Claim 41 words

A method as defined by claim 10 wherein said end is equipped with a full-opening valve, a remote connector hub, and a guide base before said pipeline is lowered back to the bottom of said body of water. with resPect sealing

Claim 13

Dependent Claim 137 words

Apparatus for recovering the end of a submerged pipeline from the bottom of a body of water which comprises an elongated tubular housing closed at one end and open at the other end, a gas inlet in said housing near the closed end, slips supported by said housing near the open end thereof for engaging the end of a pipe extending concentrically withrespect to said housing, a resilient sealing element supported by said housing near the open end thereof for forming a seal between said housing and the wall of said pipe, a piston in said housing for setting said slips and said selaing element, a hydraulic fluid inlet in said housing for introducing a fluid to actuate said piston, and a resilient, displaceable pigging element in said housing between said gas inlet and said open end.

Claim 14

Dependent Claim 137 words

Apparatus for recovering the end of a submerged pipeline from the bottom of a body of water which comprises an elongated tubular housing closed at one end and open at the other end, a gas inlet in said housing near the closed end, slips supported by said housing near the open end thereof for engaging the end of a pipe extending concentrically withrespect to said housing, a resilient sealing element supported by said housing near the open end thereof for forming a seal between said housing and the wall of said pipe, a piston in said housing for setting said slips and said selaing element, a hydraulic fluid inlet in said housing for introducing a fluid to actuate said piston, and a resilient, displaceable pigging element in said housing between said gas inlet and said open end.

Claim 15

Dependent Claim 26 words

Apparatus as defined by claim 12 wherein said slips and resilient sealing element are positioned on the inner surface of said housing near said open end.

Claim 16

Dependent Claim 26 words

Apparatus as defined by claim 12 wherein said slips and resilient sealing element are positioned on the outer surface of said housing near said open end.

Claim 17

Dependent Claim 14 words

Apparatus as defined by claim 12 wherein said pigging element is a resilient sphere.

Claim 18

Dependent Claim 23 words

Apparatus as defined by claim 12 including a check valve on said gas inlet for preventing the backflow of gas from said housing.

Claim 19

Dependent Claim 154 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening at one end thereof of sufficient internal diameter to receive the end of a marine pipeline, a gas inlet near the other end therof, and a hydraulic fluid inlet in the wall thereof; a slidable annular piston positioned in said housing, said piston and housing forming an expansible chamber communicating with said hydraulic fluid inlet; a resilient annular sealing member within said housing near said open end therof, said sealing member being of sufficient internal diameter to receive said end of said marine pipeline and of sufficient external diameter to effect a seal between said housing and said end of said pipeline; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned within said housing near said opening in said end thereof.

Claim 20

Dependent Claim 154 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening at one end thereof of sufficient internal diameter to receive the end of a marine pipeline, a gas inlet near the other end therof, and a hydraulic fluid inlet in the wall thereof; a slidable annular piston positioned in said housing, said piston and housing forming an expansible chamber communicating with said hydraulic fluid inlet; a resilient annular sealing member within said housing near said open end therof, said sealing member being of sufficient internal diameter to receive said end of said marine pipeline and of sufficient external diameter to effect a seal between said housing and said end of said pipeline; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned within said housing near said opening in said end thereof.

Claim 21

Dependent Claim 138 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet in the other end thereof, and a hydraulic fluid inlet in the wall thereof; a slidable annular piston mounted on said housing, said piston and housing forming an expansible chamber communicating with said hydraulic fluid inlet; a resilient annular sealing member mounted on said housing near said end containing said opening, the dimensions of said sealing member being sufficient to effect a seal between said housing and the end of a marine pipeline into which said housing is inserted; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned on said housing near said one end containing said opening.

Claim 22

Dependent Claim 138 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet in the other end thereof, and a hydraulic fluid inlet in the wall thereof; a slidable annular piston mounted on said housing, said piston and housing forming an expansible chamber communicating with said hydraulic fluid inlet; a resilient annular sealing member mounted on said housing near said end containing said opening, the dimensions of said sealing member being sufficient to effect a seal between said housing and the end of a marine pipeline into which said housing is inserted; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned on said housing near said one end containing said opening.

Claim 23

Dependent Claim 140 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet near the other end thereof, and a hydraulic fluid passageway in the wall thereof; a slidable annular piston forming with said housing an expansible chamber communicating with said hydraulic fluid passageway in said wall of said housing; a resilient annular sealing member positioned between said piston and said opening in said end of said housing, the dimensions of said sealing member being sufficient to effect a seal between said housing and the end of a marine pipeline extending concentrically with said housing; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned near said opening in said end of said housing.

Claim 24

Dependent Claim 140 words

Apparatus for use in offshore pipelining operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet near the other end thereof, and a hydraulic fluid passageway in the wall thereof; a slidable annular piston forming with said housing an expansible chamber communicating with said hydraulic fluid passageway in said wall of said housing; a resilient annular sealing member positioned between said piston and said opening in said end of said housing, the dimensions of said sealing member being sufficient to effect a seal between said housing and the end of a marine pipeline extending concentrically with said housing; and pipe retaining means responsive to movement of said piston for engaging and holding said end of said marine pipeline, said pipe retaining means being positioned near said opening in said end of said housing.

Claim 25

Dependent Claim 144 words

Apparatus for use in pipeline repair operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet in the other end thereof, and a hydraulic fluid inlet in the wall thereof, said opening in said one end of said housing and the interior of said housing being of sufficient size to accommodate an expansible pigging element and permit the displacement of said pigging element from said housing; a sealing member supported by said housing near said one end for forming a seal between said housing and the wall of a pipeline extending concentrically with said housing; pipe retaining means supported by said housing near said one end for engaging and holding said pipeline; and hydraulic means for actuating said sealing member and pipe retaining means in response to fluid introduced into said housing through said hydraulic fluid inlet.

Claim 26

Dependent Claim 144 words

Apparatus for use in pipeline repair operations which comprises an elongated tubular housing having an opening in one end thereof, a gas inlet in the other end thereof, and a hydraulic fluid inlet in the wall thereof, said opening in said one end of said housing and the interior of said housing being of sufficient size to accommodate an expansible pigging element and permit the displacement of said pigging element from said housing; a sealing member supported by said housing near said one end for forming a seal between said housing and the wall of a pipeline extending concentrically with said housing; pipe retaining means supported by said housing near said one end for engaging and holding said pipeline; and hydraulic means for actuating said sealing member and pipe retaining means in response to fluid introduced into said housing through said hydraulic fluid inlet.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-08-13	1977-02-12	1977-08-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-08-13	1981-02-12	1981-08-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-08-13	1985-02-12	1985-08-14	$7700.00	Window Closed / Lapsed

Recovery and repair of offshore pipelines

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag