Pathfinder Foam Caliper and Gauging Pig
The Pathfinder Pig is a bore measurement tool, with a high level of mechanical compliance, which is capable of negotiating severe restrictions in a pipeline. The simple and rugged construction makes it ideal for use in new and operational pipelines, which have not previously been pigged, and for assessment of the distribution of scale and wax deposits in operational pipelines. Equally, it provides a highly effective and economical means of monitoring the progress of cleaning operations.
The Pathfinder Pig comprises a standard polyurethane foam pig with a bore measurement sensing system integrally moulded into the foam matrix. The sensors measure the compression of the foam at points around the circumference of the tool, allowing measurement of bore changes, dents, ovality, scale and wax deposits, and other restrictions. The electronics, battery and logging system are located in a removable cartridge in the centre of the pig. On completion of an inspection run, the data cartridge is removed from the pig for data download and later re-use. The foam carrier pig will be discarded.
Key Design Features
- The measurement system comprises an array of bore-measurement sensors, and a three-axis accelerometer for measuring roll angle (clock position) and tilt.
- Sensor readings are sampled and stored on a time basis and the data file is referenced to a real time clock. Distance is estimated by comparing the on-board time reference to the pumping rates and flow records from the inspection run.
- The data file is stored in solid-state memory and, at the end of the run, it is simply offloaded via USB for viewing and analysis.
- The data can be displayed as multi-channel radius, diameter, or mean bore plots:-
- The caliper system is produced, maintained and supported by Pipeline Innovations Ltd and the foam carrier pig is produced by Propipe Ltd, a well-established supplier of foam pigs to the oil and gas industry.
- The foam pig bodies are disposable after use but the caliper pod is re-useable.
- The Pathfinder tool is simple to operate and does not normally require operation by specialist caliper technicians. A data viewer can be supplied to the client for immediate on-site data assessment. If unknown features or anomalies are present, then data can be sent to PI Ltd for expert analysis and interpretation.
For more information on Pathfinder applications see the Case History section.