System and device for monitoring a movable plug element(s) in a pipeline

1. A method for simultaneous monitoring of a pressure differential across a friction pig and a position of the friction pig to predict movement of the friction pig when the friction pig is in stationary use in and sealing against a pipeline, the friction pig having at least one pair of resilient sealing elements, the method further comprising the steps of:

using pressure sensors connected to the friction pig for acquiring data related to the differential pressure across the friction pig;

operating in different operation modes where one is a communication mode and the other is a tracking mode, the communication mode enables said pressure sensors for acquiring data related to the differential pressure and the tracking mode enables means for sending signals related to identification and position of the friction pig;

receiving instructions from a transponder of a remote control unit through a transceiver, said instructions comprises operation modes of the friction pig;

carrying out said instructions, and

transmitting said acquired data and signals to said remote control unit through said transceiver, thus enabling simultaneous monitoring of the differential pressure across the friction pig and the position of the friction pig to predict movement of the friction pig; and

predicting the movement of the friction before an movement occurs based upon a change in the differential pressure when the friction pig is in stationary use and sealing against the pipeline;

wherein the friction pig is a friction plug having no moving parts for use in pipeline isolation, the resilient sealing elements being the sole means of holding the friction plug in a stationary, sealing position within the pipeline.

2. A method according to claim 1 wherein one of the pressure sensors is located upstream of the friction pig, and another of the pressure sensors is located downstream of the friction pig.

3. A method according to claim 1 further comprising other sensors are sensors for measuring temperature, volume, axial position in the pipeline, acceleration, travelled distance in the pipeline or gas leaking through the friction pig.

4. A method according to claim 1 wherein the step for transmitting data comprises a transponder connected to the friction pig and configured for receiving data from the sensor, and a transceiver on the outside of the pipeline.

5. A method for simultaneous monitoring of a pressure differential across a friction pig and a position of the friction pig to predict movement of a plurality of friction pigs when in stationary use in a pipeline and sealing against the pipeline, the method comprising the steps of: positioning two or more mutually independent friction pigs into a stationary position, each having at least one pair of resilient sealing elements being the sole means of holding the friction pigs in the stationary position when in use in the pipeline and pressure sensors connected to at least one of the friction pigs for acquiring data related to differential pressure across the at least one friction pig, wherein the friction pigs are friction plugs having no moving parts for use in pipeline isolation; operating said friction pigs in different operation modes where one is a communication mode and another is a tracking mode, and where the communication mode enables acquiring data related to differential pressure across the at least one friction pig and where the tracking mode enables means for sending signals related to identification and position of each friction pig; receiving and carrying out instructions in the at least one friction pig from a remote control unit through a transceiver outside the pipeline, said instructions comprise operation modes of the friction pigs, transmitting said acquired data and signals to said remote control unit through said transceiver; thus enabling simultaneous monitoring of the differential pressure across the at least one friction pig and the position of the at least one friction pig to predict movement of the at least one friction pig; and predicting the movement of the at least one friction pig when the friction pig is in the stationary position and sealing against the pipeline.

6. A method according to claim 5 wherein the friction pigs are located 1-10 meters from each other.

7. A method according to claim 5 wherein one friction pig is master, and another friction pig is slave, and where the master friction pig comprises a transponder configured for receiving data from the sensors of the friction pigs, and for sending acquired data to the transceiver outside the pipeline.

8. A method according to claim 5 wherein one of the pressure sensors is located upstream, and another of the pressure sensors is located downstream of the set of friction pigs.

9. A method according to claim 5 further comprising another sensor for measuring at least one of a temperature, volume, axial position in the pipeline, acceleration, travelled distance in the pipeline or gas leaking through one or both of the friction pigs.

10. A method according to claim 1 wherein the remote control unit is not in communication with the sealing elements.

11. A method according to claim 5 wherein the remote control unit is not in communication with the sealing elements.