Design and Testing of Fiberbuilt’s New Corrosion Pit Cleaning Pig
NACE NAWC 2017 Presentation: Performance and Analysis of a New Pipeline Pig Design for the Removal of Deposits from Corrosion Pits
Pipeline corrosion mitigation is critically important to ensure the safe and responsible operation of the world’s pipeline infrastructure. Pipeline maintenance and cleaning pigs are typically utilized in an overall pigging program which can include pigging stages for debris and wax removal, scouring and cleaning of the interior pipe walls to prepare the pipe inside surface for chemical application.
Cleaning internal corrosion pits presents a specific challenge in pigging and corrosion mitigation. Localized pitting in pipelines can create zones of Under-Deposit Corrosion (UDC) and the ideal environment for Microbially Induced Corrosion (MIC). The small diameter pit deep into the pipeline wall represents the most challenging scenario. If allowed to progress without effective cleaning, these small corrosion pits can lead to ‘pinhole’ pipeline leaks that are difficult to detect but can lead to significant environmental incidents.
The Pipeline Integrity and Corrosion Monitoring (PICOM) team at Alberta Innovates Technology Futures (AITF) has developed and previously presented a standardized testing methodology and flow loop to quantify the effectiveness of pigging for cleaning corrosion pits. These detailed studies identified that significant improvements beyond currently available cleaning pigs are required to more effectively address cleaning corrosion pits.
Fiberbuilt Manufacturing has developed a new pipeline pig system to address and improve the cleaning of these pipeline corrosion pit features. This newly developed pigging system was tested to quantitatively determine the improved corrosion pit cleaning performance. The new Fiberbuilt pigging system was also tested in multiple pigging run scenarios to determine and define the optimum strategy for corrosion pit cleaning as a part of the overall mitigation pigging program. The results of the Fiberbuilt corrosion pit cleaning test and evaluation program will be presented here.
In addition to the corrosion pit cleaning, this pigging system utilizes a next generation seal platform that provides an effective pigging seal with only a very low differential pressure required. Upstream multi-phase gathering systems may have very little available drive pressure which can lead to problems in pigging these lines effectively. A very low differential pressure pigging system will allow upstream gathering lines with low available pressure drive to be pigged effectively at a higher frequency without restricting well productivity in the gathering system. The Fiberbuilt seal platform creates a customizable drag (operating differential pressure) for pipeline pigs that can virtually eliminate pig surging, providing a stable pigging speed profile that improves overall pig performance. Detailed results including demonstrations of the customization of operating back pressure will be presented.