Eni has developed and applied in the field a set of technologies aimed at pipeline data acquisition with low-risk pigs, to address issues related to Flow Assurance (e.g. internal deposits) and Pipeline Integrity (such as steel deformations, some forms of internal metal loss, etc.). The overarching concept of such technologies is to readily transform any pig (especially those which present very low risk of creating production problems) into data acquisition tools, which can acquire data along the trip and provide useful information to operators and specialist.
The acquisition systems are required to introduce negligible risks. As such, they have been chosen to be mostly made of plastic, have a density matching that of the liquid phases, have a rounded shape, and so on. All feature choices were made to limit their possibility of getting stuck in the pipeline or introduce additional pigging problems. Among the data acquired, we have typically deployed sensors that log pressure (including pressure drop across the pig), temperature and 3-axis accelerometer/gyroscope (pig pitch, roll, orientation, right/left turns).
While in the past we have preferably applied commercial sensors, we have sometimes experienced limitations with respect to our specific applications, requiring high pressure (reaching 200 bar and more), rather high temperatures (above 70° C in some pipelines), small diameters (less than 2” in some cases), presence of aggressive solvents damaging electrical contacts, high sampling rates (up to 200 samples per second for some applications), etc.
Given the proven usefulness of such technology in many operating contexts, we have decided to address the above limitations and constraints in a structured way, by designing and implementing two sensing platforms, packaged in a plastic floating container, suitable to address all the objectives, including high working pressures (200 bar, but potentially higher), small diameter (less than 2”, and for low pressures, less than 1”), high sampling rates (200 s/s), wireless battery charging and data transfer, wide set of sensors (pressure,, temperature, acceleration, gyros, deformation) and GPS for applications where the satellite signal is not screened. Finally, for our proprietary plastic caliper pig, a specific implementation allows battery-less deformation sensors to receive power and transmit high-frequency data by a new wireless coupling.
The platforms have been designed, implemented and field tested and are available for field applications in Eni, providing Flow Assurance and Pipeline Integrity data for years to come.
