Method and apparatus for remotely and releasably sealing a pipeline

Claim 3

(b) generating a higher thermal command signal of a second temperature higher than the first temperature for sealing the pipe with the forward pig responsive to the higher second temperature at the downstream end of the pipe section to be sealed off.

Claim 4

(b) generating a higher thermal command signal of a second temperature higher than the first temperature for sealing the pipe with the forward pig responsive to the higher second temperature at the downstream end of the pipe section to be sealed off.

Claim 5

A method as recited in claim 1 wherein the two sealing pigs are interconnected comprising the additional steps after the first step of, (a) generating at the upstream end of the pipe section a third thermal command signal of a third temperature higher than the first temperature for disconnecting the forward pig responsive to said third temperature after the aft pig has sealed the pipe, and (b) introducing another fluid intermediate the two pigs for transporting the forward pig to the other and downstream end of the pipe section to be sealed off.

Claim 6

A method as recited in claim 1 comprising the additional step of, (a) generating a third and higher thermal command signal of a third temperature at the upstream end of the pipe section for unsealing the aft pig responsive to said third temperature for allowing it to travel downstream to the forward pig.

Claim 7

A method as recited in claim 3 comprising the added step of, (a) generating at the downstream end of the pipe section a third and higher thermal command signal of a third temperature higher than the second temperature at the downstream end of the pipe section for unsealing the forward pig responsive to said third temperature as the unsealed aft pig arrives at the downstream end of the pipe section so that both pigs may continue downstream for recovery.

Claim 8

A pipe mechanism for sealing off a section of pipe of moving fluid comprising, (a) two pigs positioned in the pipe of moving fluid at a predetermined distance apart, (b) expanding means on each of said pigs for releasably sealing said pigs in the pipe for sealing off the pipe section between said pigs, (c) variable thermal generator means at each end of said section of pipe to be sealed off for generating thermal command signals of two different precise temperature levels, (d) thermal receiver means in each of said pigs, each thermal command signal receiver means being compatible with a different thermal command signal generator means and responsive to its two temperature level thermal command signals for controlling said expanding means for releasably sealing said pigs in the pipe, and (e) each of said thermal command signal receiving means being responsive to one of said two temperature levels of its respective compatible variable thermal command signal generating means for sealing said pigs at said pipe section for work thereon.

Claim 9

A pipe mechanism for sealing off a section of pipe of moving fluid comprising, (a) two pigs positioned in the pipe of moving fluid at a predetermined distance apart, (b) expanding means on each of said pigs for releasably sealing said pigs in the pipe for sealing off the pipe section between said pigs, (c) variable thermal generator means at each end of said section of pipe to be sealed off for generating thermal command signals of two different precise temperature levels, (d) thermal receiver means in each of said pigs, each thermal command signal receiver means being compatible with a different thermal command signal generator means and responsive to its two temperature level thermal command signals for controlling said expanding means for releasably sealing said pigs in the pipe, and (e) each of said thermal command signal receiving means being responsive to one of said two temperature levels of its respective compatible variable thermal command signal generating means for sealing said pigs at said pipe section for work thereon.

Claim 10

An apparatus as recited in claim 5 wherein said thermal command signal receiver means comprises, (a) a different thermal command signal receiver mounted on each pig and each thermal command signal receiver being connected to its respective inflatable means on its respective pig for actuation thereof, and (b) each thermal command signal receiver being responsive to a thermal command signal of a different temperature level generated by its respective variable thermal command signal generator for releasably sealing its pig in the pipe at the precise location of its thermal command signal generator.

Claim 11

A releasable plugging apparatus for a pipe comprising, (a) two interconnected pigs having expanding means on each pig for releasably sealing the pigs in the pipe, two thermal command signal generator means, and thermal command signal receiver means thereon each of said pigs for controlling each of said expanding means, (b) each of said thermal command signal receiver means being responsive to a thermal command signal of a different temperature generated by each of said thermal command signal generator means for releasably sealing each of said interconnected pigs in the pipe, and (c) each of said thermal command signal receiver means being responsive to a higher thermal command signal generated by each of said thermal command generator means for unsealing each of said interconnected pigs in the pipe.

Claim 12

A releasable plugging apparatus for a pipe comprising, (a) two interconnected pigs having expanding means on each pig for releasably sealing the pigs in the pipe, two thermal command signal generator means, and thermal command signal receiver means thereon each of said pigs for controlling each of said expanding means, (b) each of said thermal command signal receiver means being responsive to a thermal command signal of a different temperature generated by each of said thermal command signal generator means for releasably sealing each of said interconnected pigs in the pipe, and (c) each of said thermal command signal receiver means being responsive to a higher thermal command signal generated by each of said thermal command generator means for unsealing each of said interconnected pigs in the pipe.

Claim 13

A releasable sealing apparatus for a pipe comprising, (a) pipe internal sealing means having expanding means for releasably sealing the internal sealing means in the pipe and remote command thermal signal receiver means thereon for controlling said expanding means, (b) said remote command thermal signal receiver means being responsive to a first command thermal signal of a particular temperture level for actuating said expanding means for releasably sealing the pipe, (c) remote command variable thermal signal generator means at a precise location on the pipe, (d) said remote command thermal signal generator means generates said first remote command thermal signal of a particular temperature level, and (e) said remote command thermal signal receiver means being responsive to said first command thermal signal generated by said remote command thermal signal generator means for releasably sealing said internal sealing means in the pipe.

Claim 14

A releasable sealing apparatus for a pipe comprising, (a) pipe internal sealing means having expanding means for releasably sealing the internal sealing means in the pipe and remote command thermal signal receiver means thereon for controlling said expanding means, (b) said remote command thermal signal receiver means being responsive to a first command thermal signal of a particular temperture level for actuating said expanding means for releasably sealing the pipe, (c) remote command variable thermal signal generator means at a precise location on the pipe, (d) said remote command thermal signal generator means generates said first remote command thermal signal of a particular temperature level, and (e) said remote command thermal signal receiver means being responsive to said first command thermal signal generated by said remote command thermal signal generator means for releasably sealing said internal sealing means in the pipe.

Claim 15

A releasable sealing apparatus as recited in claim 8 wherein, (a) said remote command thermal signal receiver means is responsive to a second command thermal signal of a higher temperature level generated by said remote command variable thermal signal generator means for unsealing said internal sealing means in the pipe.