Smart Pigs, also called In-Line Inspection (ILI) tools, are a leading-edge pipeline inspection technique where a sensor-equipped device (or Smart Pig) travels through a pipeline to detect any possible corrosion, dents and other defects that affect performance and safety. These runs help gather data on the pipe’s overall condition and help operators stay within compliance by catching small problems before they turn into potentially expensive failures.
When a Smart Pig run stalls or produces unusable data, the pipeline stays out of service for a longer period of time, and the tool may have to run again.
Most delays come from just a few avoidable causes. By identifying these potential causes and choosing the right partner for your pipeline pigging services, you can keep your inspection on track, within compliance, and keep your crew safe.
Common Reasons Smart Pigging Projects Get Delayed
Smart Pigging is a highly effective way to inspect a pipeline’s integrity. But a successful run truly depends on much more than the inspection tool itself. From propellant supply and line conditions to contractor coordination, site management, site access and weather, there are several factors that can affect whether or not a project stays on schedule.
Speed Excursions and Missing Data
Every ILI tool is built to operate within a specific speed range. If the tool moves too quickly or too slowly through the pipe, the quality of the data that is collected can be inaccurate or incomplete, potentially requiring the run to be repeated.
Gas pipelines can be particularly susceptible to sudden speed changes as operating conditions fluctuate. Maintaining consistent propellant supply is critical to controlling the tool’s velocity through the pipe. Stable pressure and flow from the launch through to receipt can help keep the inspection process smooth and reduce the risk of incomplete or unusable data.
Running Short on Propellant
Pipelines that are out of service or operating with limited product flow may not have enough natural flow to propel the ILI tool through the line. This is where many operators rely on bulk nitrogen to drive the pig, but a delay can occur when nitrogen is delivered in bulk later than scheduled or when the required volume is underestimated.
Planning the required nitrogen volume in advance, or using pipeline nitrogen services that generate gaseous onsite supply of nitrogen, removes that risk.
Debris in the Line
Scale, wax, rust, sediment and other deposits can interfere with an ILI’s tool’s movement through the pipeline. Excessive debris may slow the tool, damage components, or, in severe cases, prevent the tool from completing the run. A thorough cleaning program before Smart Pigging helps remove accumulated material and creates better line conditions for the inspection tool.
Water Left in the Line
Residual water can create complications during a Smart Pigging operation, especially when water has been introduced through hydrostatic testing or other pipeline activities. Depending on the application, remaining moisture may require additional removal, treatment or disposal before the inspection can move forward.
Every litre must be removed, treated, and disposed of afterward. Using gaseous nitrogen as the propellant avoids the extra dewatering step and leaves the line dry and ready for operation.
Access Constraints
Pipeline launch and receiving sites are often situated in more remote areas where access can present its own logistical challenges. Some roads may have seasonal restrictions, weight limitations or insufficient capacity for the equipment required to support the pigging operation. Access requirements should always be reviewed well before mobilization of the operation.
Always ensure road access is confirmed, weight restrictions are considered, and lay-down space for all crew and nitrogen equipment is established to avoid delays when the project is underway.
Vendor Management
Smart Pigging typically involves coordination between multiple parties, including the ILI provider, nitrogen supplier, pipeline operator and the clean-up crew. The inspection cannot proceed efficiently if one contractor arrives late, equipment is unavailable, or responsibilities have not been clearly established. Before mobilization, all parties involved should confirm equipment readiness, arrival times, operating requirements and individual responsibilities.
Safety Planning Gaps
Opening pipeline launchers and receivers, particularly on lines that have contained hydrocarbons, requires careful planning and appropriate safety measures. Nitrogen is an inert gas, but it can displace oxygen and create an asphyxiation hazard in confined or poorly ventilated areas. Opening launchers and receivers on a line that has carried hydrocarbons requires a proper purge plan. Unclear procedures, unqualified contractors or an incomplete purge or isolation plan can create both safety concerns and significant project delays.
Safety requirements and atmospheric monitoring should always be established and reviewed before the operation begins.
Weather Windows
In Western Canada, weather and seasonal conditions can have a significant impact on pipeline inspection schedules. Spring road restrictions can limit access to remote sites, while extreme winter conditions can create equipment and operating challenges due to the drop in freezing temperatures, leaving the water that’s left in the line to freeze. If a weather window is missed, the operation may have to be postponed by weeks or even months.
The Role of Onsite Nitrogen During Smart Pigging
Nitrogen does several jobs during an ILI program. It propels the smart pig through the pipeline, including lines with no product flowing. Because supply can be regulated, operators can manage pressure and flow to keep the tool within its required speed range.
Nitrogen is also an inert gas that displaces the oxygen in lines that have carried hydrocarbons, preventing combustion and oxidation while the crews work. Its low dew point dries the line as the tool moves, reducing corrosion risk. Using nitrogen during pigging can also reduce the number of pig runs and cleaning time, and cut down on the brush pigs and foam swabs needed to dry a line to a specified dew point.
The leading benefit of on-site nitrogen production is that it eliminates the reliance on bulk deliveries. As long as the job requires it, the supply continues without having to put the project on hold or running out of nitrogen mid-operation.
How Canadian Nitrogen Services Assists Smart Pigging Projects
A successful Smart Pigging project depends on more than the inspection tool itself. The pipeline always needs to be properly prepared, and the inspection tool needs a reliable means of propulsion and operating conditions need to remain controlled throughout the run. For pipelines where natural product flow is insufficient, nitrogen can provide the controlled propellant needed to move the tool through the line.
At Canadian Nitrogen Services, we provide mobile membrane nitrogen generation for pipeline applications, producing nitrogen on-site at purities ranging from 95% to 99%, and provide continuous supply for operations where transporting large volumes of nitrogen to a remote site would be impractical or costly.
At Canadian Nitrogen Services, our support extends beyond the supply of nitrogen for the inspection run. We also provide a range of pipeline purging, drying, inerting, pressure testing, commissioning and suspension, as well as pigging applications using scraper, calliper, and foam pigs.
Our services are provided across the Northwest Territories, northern British Columbia, Alberta, central and southern Saskatchewan, and Manitoba, and cover remote locations.
Plan Your Next Run Effectively | Canadian Nitrogen Services Is Ready
At Canadian Nitrogen Services, we bring over two decades of experience with mobile on-site nitrogen generation and are proud to maintain a Certificate of Recognition (COR) through Energy Safety Canada.
To discuss pipeline nitrogen services for your next ILI project, contact Canadian Nitrogen Services today or give us a call at 1-877-284-0404. We’re ready to help!
