Reducing the cost of inline inspection
Pigging is the most common form of inline inspection used by oil and gas pipeline owners. There are two ways of tracking a pig through a pipeline; legacy tracking and remote tracking. Historically, pigs have been tracked using legacy methods, where a field technician would follow the pig from site to site to confirm its location and ensure the pig reaches the trap.
Remote tracking combines leading-edge above ground markers (AGMs) and Remote Tracking Units (RTU’s) that are pre-deployed before an ILI run and are used to track the pig from a central location. As a pig approaches a tracking site, the remote unit is activated to track the tool, and does not require a field technician to be on site.
It is a common misconception that remote tracking is more expensive than traditional legacy tracking methods due to the presence of advanced technology; however, remote tracking is often significantly cheaper than legacy tracking.
When to use remote tracking
Remote tracking is less expensive than legacy tracking when there are multiple pig runs or accessibility issues with tracking locations. Using remote tracking, each site only needs to be accessed twice – for equipment deployment and retrieval. Using legacy methods for a multi-pig run would require trackers to access each site multiple times, which can significantly increase costs.
While this seems insignificant, reducing the number of field trackers, trucks, and subsistence charges can drastically reduce a project’s cost. In addition, remote tracking helps to normalize project costs, as unexpected delays or standby days don’t result in additional costs for the pipeline owner.
Before any ILI run, pipeline owners should evaluate all the potential risks and costs to determine the best method of tracking the pig. If multiple pig runs need to be conducted, tracking locations are inaccessible, or if the run will span over a long distance, remote tracking can save pipeline owners upwards of 50 percent compared to traditional legacy tracking.