GB2227805A - Remotely controlled pipeline plug or pig - Google Patents

Abstract

A pipeline plug 3, Fig 1 or pig 20, Fig 4 comprises a remotely controlled, but self-contained, activation and release system. The pipeline plug 3 can be a sphere, a pair of articulated spheres (Fig 3), a train of spheres, a sphere tethering pigs, or a combination thereof. The plug 3 or pig 20 is remotely controlled totally independent of the internal and/or external conditions of said pipeline to effect a seal inside the pipeline. The seal may be effected by expanding plug cavity 6 by various means eg gas, liquid, foam or polymer from a cylinder 4 actuated by a receiver 17 responding to a remote control 13. Other expanding devices eg. spring-loaded linkages are described. The seal may be released by depressing cavity 6 through port 9 and then through adjacent ports 10, 11. <IMAGE>

Description

REMOTELY CONTROLLED PIPELINE PLUG The present invention relates to a remotely controlled device for use in plugging and isolating pipelines. Such a device, or combination of devices are more particularly comprised of a sphere, pig, or train of spheres and/or pigs for travelling through a pipeline.

In an emergency, or in special circumstances, it would be necessary to isolate and/or plug a pipeline at a selected location. Such a location may be where a leakage may exist, or there is a damaged section of pipeline.

The particular section, regardless of its location along the pipeline, may need to be tested, repaired, welded, or even replaced by a new pipeline Joint or component.

The removal of a pipeline section may also entail the installation of a flange, combination of flanges, Joints, spool pieces, or a combination thereof. The pipeline section may also incorpqrate an isolation valve or require the installation of such a pipeline component.

It a particular pipeline is empty or under pressure or even contains liquid or gasses, and there is a need for it to be held at a specific pressure or to be preserved from external or internal contamination, then the line must be isolated or plugged to prevent leakage.

The contamination or leakage can be by means of ingress or exfiltration of constituents or extraneous matter. In other circumstances, where the pipeline has to be cut for a particular repair operation, then volatile constituents must be prevented from igniting or being released into the environment. Such a release can be into the atmosphere, underground, or even under water, viz. subsea.

Conventional methods of pipeline repair have entailed the decommissioning of the said pipeline and water flooding or inverting the entire pipeline to prevent explosion or contamination hazards.

The pipeline section under repair would subsequently be contained within a special habitat, to enable the repair work to be undertaken. This practise is applied to subsea pipelines where a habitat is normally used, to enable repair personnel to operate under water.

The present invention obviates the dangers emanating from pressure fluctuations under water. The said invention also eliminates the need for decommissioning, flooding, or inerting the entire pipeline.

Other devices have been utilised in the past, hence effecting pipeline plugging from within the pipeline. Such devices have either been tethered and controlled by umbilical hosses and/or lines, or have incorporated special inlet and outlet ports to effect hydraulic or pneumatic pressurization from inside the pipeline and subsequently effect a pipeline plug.

The present invention negates the need for tethering or @@@ @@@ @@@@@ @ @@@@ @@@@ @@@@ @@@@ @@ @@@@@@@ @@@@@@ p@es@@@ @z@@@@@ @@ @@@ p@p@@@@@ @@ a@@@@vs @@@ plugging result. The present invention employs, from within, a self-contained pressurization and/or actuation system which can be either pneumatic, hydraulic, mechanical, electrical or any combination thereof of these techniques.

The activation of the internal plug can be applied by a special time switch which can then be de-activated, either remotely, or by a pre-programmed sequence.

One unique feature of the present invention is that it is remotely controlled and is independent of the internal and external conditions of the pipeline Another feature of the present invention is the ease with which the device can be positioned at the required location by remote triggering of the internal actuators.

The latter would pressurize and/or actuate inflatable and/or expandable sections to effect a firm and secure plug within the pipeline.

The configuration of a remotely controlled pipeline plug, in accordance with the present invention, will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of one example of a sphere plug; Figure 2 shows the mode of operation when two sphere plugs are utilised to isolate the pipeline section under repair. The control and actuator system details of the sphere plugs have been ommitted.

Figure 3 is a diagrammatic representation of an articulated combination of two sphere plugs; Figure 4 is a diagrammatic view of a pipeline pig incorporating similar control and actuator system of a sphere plug as illustrated in Figure 1.

A sphere plug device 3, of the present invention (as illustrated in Figure 1) is for travelling inside a pipeline 1, in close proximity to or neatly fitting within the pipeline's internal surface 2. The plug, in this respect can be a sphere, spheroid, rhombohedron or any other shape or configuration.

Inflatable and/or expandable cavavity 6, can be highly elastic bladders, which can be inflated or expanded by pneumatic, hydraulic, mechanical, electrical, thermal or a chemical means or combination thereof.

The elastic bladder can also be replaced by a metallic membrane or other suitable material, which can be rubber, leather, fibre-glass, plastic or any other polymer, or combination thereof, or any other material which lends itself to forming a durable and/or a temporary, but secure seal inside the pipeline.

A durable or a temporary seal which would effectively plug the pipeline can also be formed by mechanical means, incorporating spring-loaded linkages or diaphragms actuated by pneumatic, hydraulic, electo-mechanical, thermal or any other actuator energized from within the plugging device, after having been activated by remote control.

The cavity 6, or any number of cavities, of the sphere plug can either be totally empty or filled with a suitable gas, liquid, polymer, foam, or spring-loaded or any other suitable material or means.

The control and actuating system is contained within a special compartment 5, which can be s#herical, cylindrical, or any other configuration of any 5U ble material The compartment 5, can be permane tly positioned within the sphere plug 3 and cavity 6, by structural webbing or linkages Sa, in any suitable number and/or material to support compartment 5. Compartment 5, can also be of a removable configuration, which would incorporate sealing joints or flanges (not shown) to enable servicing, testing, and re-charging of the batteries 12, or pressurizing cylinder 4.

The pressurizing cylinder 4, can be filled with any suitable gas, liquid, polymer, foam, catalyst or any other means of pneumatic, hydraulic, or thermal pressurization of the cavity 6. The pressurization cylinder 4, can be of any shape, configuration or design, or any number of such cylinders, necessary to effect a plug within the pipeline.

The pressurization cylinder 4, can be connected to cavity 6, via an internal port 9, after opening valve 7.

Depressurization and/or de-activation of the plug can be effected via valve 8, which leads to ports 10 and 11, and thence to the outside of the plug body 3. Depressurization ports 10 and 11, can be one port, or any other number of ports that are required to enable the sphere plug to be initially charged prior to entering the pipeline, and subsequently depressurized.

A feature of the present invention, is that ports 10 and 11 are in close proximity to one another, to prevent the plug from by-passing from one si3e of the isolated pipeline to the other. The reason for the close proximity of ports 10 and 11, is to enable the sphere plug to be depressurized in the event that either of the ports engages the internal pipeline wall 2, shown in Figure 1.

The remote control 13, which can be one or more units, (as shown in Figure 1) for the present invention, can be effected by means of electronic, electro-magnetic, magnetic, acoustic or ultra-sonic, or any other mechanical, hydraulic, electical, radioactive or thermal technique or combination thereof. The remote control unit 13, can be located anywhere along the pipeline, or may even be positioned inside the pipeline.

l t i T 5 , n , Inside the control unit will incorporate a decoder 16, so as to prevent false activation by spurious signals or field interference.

The decoder 16, is in direct communication with valve actuators 15, for co-ordination and necessary activation of a particular mode of operation. To effect the activation of the sphere plug inside a pipeline, the remote control unit 13, would transmit the required coded signal. The receiver 17, would transmit the signal to the decoder 16, which triggers the actuator 15 of valve 7. The latter would subsequently allow pressure from cylinder 4, to pass through port 9, and into the pressurization cavity 6, hence forming a plug inside the pipeline.

Another feature of the present invention is that a transmitter 14, would be able to verify that the plug has been activated. Verification shall either be by pressure, electrical, electronic, magnetic, acoustic, or any other suitable means, which would be communicated to the remote control unit 13. To de-activate the sphere plug, the remote control unit 13, would transmit a coded signal which would be received by 17, and transmitted to the decoder 18. After the signal has been decoded and identified, the relevant actuator 15, would open valve 8, and subsequently allow cavity 6 to depressurize, via ports 9, 10, and 11.

Another feature of this invention is the ability of the plugging device to carry a beacon 18, namely a device which is normally termed in pipeline technology as a "pinger" or "transponder". A "pinger" is normally utilised for gas pipelines and a "transponder" for liquid-filled pipelines.

Either of these devices, or combination thereof, can be utilised to identify the location and/or the presence of the pipeline plugging device.

The control unit of the present invention will be energized by a battery package 12, which would provide the required power for activation and control.

The battery package can be a single re-chargeable power supply unit, or any other number or combination of batteries as deemed necessary, to provide sufficient power over the designated period of time of operation. The power supply may also be provided by an engine, or internal generator (not shown) which can be driven by mechanical, hydraulic, pneumatic, electrical, or any other suitable means.

Another configuration of a remotely controlled pipeline plug may take the form of a pig, as illustrated in Figure 4.

The pig would travel inside the pipeline 1, in such a way that the discs or pig cups would engage the pipeline's internal surface 2. The pig body 20, may comprise one disc 21, or multiple numbers of discs in any combination or numbers required. The pig body 20, or discs or cups 21, can be made from any suitable material, to house the control unit, to effect a pipeline plug similar to that described earlier and as illustrated in Figures 1.

The exception here is that the sealing membrane or parts 19, would be of any suitable material, so as to be incorporated within the annular compartment of a pipeline pig 20. The activation of the pipeline seal 19, can be effected by the same means of control and actuation system, as described for the sphere plug. The pipeline seals can be made of any suitable material and any shape and number required to effect a permanent or temporary but secure, pipeline internal plug. This plug, or plugs, can be activated and released by remote control 13.

The most advantageous feature of the present invention, irrespective of its configuration or shape, or its being a sphere plug, combination of spheres or articulated sphere plugs, pipeline plugging pig, combination of pig plugs or trains or pig plugs; is that such a plugging device, or devices, are self-contained and can be activated and remotely controlled by a variety of means, as described earlier.

Claims (10)

1. A pip@@@@ rem@te@@ @@@@@@@led plu; comprises a sphere or a combination or sp,--r-s or articulated spheres tor travelling through a pipeline to etfect a plug tram within the pipeline at a selected location.

2. A device according to claim I, where the means or effecting the pipeline internal plug can be a sphere tethering pig or an articulated Pis, or a train at pigs either tethering or incorporating a sphere plun to be activated by remote control.

3. A device according to claim I and claim ., whcrein a remote control, which can be mcnanicaj, acoustic, ultrasonic, pneumatic, hydraulic, electrical, clectro- magnetic, magnetic, electronic, thermal, radioactive or any other suitable means to applv activation anU/or riea or d control system from within the device a in claim 1 or claim 2, is utilised to eftect a pipeline interna ] plug.

4. A device according to any at the preceding claims, for use in a pipeline or a duct or any length he or diameter, or any material, to tarm a rematelv controlled plug.

5. A device according to any of the preceding claims, with the means of forming a plug as energized and applied from within the device by means at a pressure cylinder or compartment, which can be pneumatic, magnetic, hydraulic, electical motor or an engine.

6. A device according to claim 5, where the pressure cylinder or compartment contains gas, liquid, polymer, toam, catalyst or any other suitable material or means, to effect a pipeline internal plug.

7. A device according to any of the preceding claims, where a sphere plug or combination thereof, or a pig, or a train of sphere tethering pigs, or combination thereof, would comprise a sealing sphere compartment to effect a pipeline internal plug or plugs.

8. A device according to any of the preceding claims for forming a self-contained pipeline plug independent of the internal or external conditions of the pipeline.

9. A device according to any of the preceding claims, further including a power package to energize the control and activation system from within the plug device.

10. A device according to any of the preceding claims, substantially as described, with reference to the accompanying drawings.