US4252465A — Pipeline gel plug

Claim 1

Independent Claim 70 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline, comprising preparing a Bingham plastic gel plug, inserting the gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, and maintaining the predetermined distance of the plug from the vessel as the pipeline is deployed.

Claim 2

Independent Claim 70 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline, comprising preparing a Bingham plastic gel plug, inserting the gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, and maintaining the predetermined distance of the plug from the vessel as the pipeline is deployed.

Claim 3

Dependent Claim 40 words

The method of claim 1 including adding pipe segments to the pipeline from the vessel and moving the gel plug as the pipe segments are added in order to maintain the pre-determined distance of the gel plug from the vessel.

Claim 4

Dependent Claim 53 words

The method of claim 1 including adding pipe segments to the pipeline at an onshore location, pulling the pipeline offshore by the vessel, and retaining the gel plug essentially stationary within the pipeline as the pipe segments are added in order to maintain the predetermined distance of the gel plug from the vessel.

Claim 5

Dependent Claim 24 words

The method of claim 1 including adjusting the position of the gel plug by applying gas pressure from the vessel end of the pipeline.

Claim 6

Dependent Claim 25 words

The method of claim 1 including continuously positioning the front of the gel plug at approximately the vicinity of where the pipeline first touches bottom.

Claim 7

Independent Claim 104 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline, wherein the pipeline extends from onshore to the vessel, comprising inserting a gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, and pressuring the gel plug by fluid from the shore end of the pipeline to a position in the pipeline just behind the vessel and maintaining the gel plug by fluid pressure at the predetermined distance from the vessel as additional pipeline is laid from the vessel.

Claim 8

Independent Claim 104 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline, wherein the pipeline extends from onshore to the vessel, comprising inserting a gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, and pressuring the gel plug by fluid from the shore end of the pipeline to a position in the pipeline just behind the vessel and maintaining the gel plug by fluid pressure at the predetermined distance from the vessel as additional pipeline is laid from the vessel.

Claim 9

Independent Claim 111 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline and for temporarily sealing and sinking one end of the pipeline, comprising inserting a gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, maintaining the predetermined distance of the plug from the vessel as the pipeline is deployed, sealing the end of the pipeline adjacent the vessel, and pressuring the liquid-filled segment of the pipeline to reduce the volume of the gas-filled segment in the pipeline adjacent the sealed end, whereby the sealed end sinks.

Claim 10

Independent Claim 111 words

A method for liquid-fill weighting an offshore pipeline to within a predetermined distance from a vessel which is deploying the pipeline and for temporarily sealing and sinking one end of the pipeline, comprising inserting a gel plug into the pipeline to separate a gas-filled segment of the pipeline adjacent to the vessel from a liquid-filled segment of the pipeline, maintaining the predetermined distance of the plug from the vessel as the pipeline is deployed, sealing the end of the pipeline adjacent the vessel, and pressuring the liquid-filled segment of the pipeline to reduce the volume of the gas-filled segment in the pipeline adjacent the sealed end, whereby the sealed end sinks.

Claim 11

Dependent Claim 36 words

The method of claim 7 including retrieving the sealed end of the pipeline by reducing pressure on the liquid-filled segment, whereby the gas-filled volume expands and the sealed end floats or is sufficiently light for pick-up.

Claim 12

Dependent Claim 14 words

The method of claim 1, wherein the gel plug is a nonthixotropic Bingham plastic.

Claim 13

Dependent Claim 28 words

The method of claim 3 including determining the location of the gel plug by measuring the amount of fluid added to the pipeline to move the gel plug.

Claim 14

Dependent Claim 30 words

The method of claim 3 including preceding and following the gel plug with transponders or markers locating the front and rear of the gel plug with respect to the pipeline.

Claim 15

Dependent Claim 26 words

The method of claim 3 including preceding and following the gel plug by pigs separating the gel plug from fluids or gasses present in the pipeline.

Claim 16

Dependent Claim 13 words

The method of claim 12 including locating transponders or markers inside the pigs.

Claim 17

Dependent Claim 24 words

The method of claim 1 including inserting a pump into the pipeline between the gel plug and vessel and removing fluid which accumulates therein.

Claim 18

Dependent Claim 21 words

The method of claim 6 including measuring gel plug yield, at least intermittently, by observing onshore pressure when plug movement ceases.

Claim 19

Dependent Claim 27 words

The method of claim 6 including measuring gel plug yield and viscosity, at least intermittently, by correlating fluid pump discharge pressure at two or three pumping rates.

Claim 20

Dependent Claim 29 words

The method of claim 6 including measuring gel plug integrity, at least intermittently, by calculating plug length between transponders which locate the front and rear of the gel plug.

Claim 21

Dependent Claim 15 words

The method of claim 12, wherein the pigs are spheres of low-durometer hardness urethane rubber.

Claim 22

Dependent Claim 18 words

The method of claim 3 including inserting a dye into the fluid to assist in locating pipeline breaks.

Claim 23

Dependent Claim 22 words

The method of claim 1 including replenishing the gel plug by installing a tap in the pipeline and introducing replenishing material therethrough.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-02-24	1984-08-25	1985-02-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-02-24	1988-08-25	1989-02-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-02-24	1992-08-25	1993-02-24	$7700.00	Window Closed / Lapsed

Pipeline gel plug

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