Preparing a valuable asset for the next chapter of service
Engineering, planning, monitoring, and troubleshooting the nitrogen displacement of a 525-mile pipeline.
- Safely delivered and recouped the value of 183,000 bbls of manufacturing feedstock product
- Readied the underutilized pipeline asset for repurposing
- Positioned the asset to generate revenue
“The only constant in life is change.”- Heraclitus
As markets shift and customers come and go, energy transportation infrastructure operators sometimes find themselves with a pipeline to nowhere and a need to adapt to the new reality. The first order of business is to recover the value of the product stored in the line and prepare it to safely weather a period of inactivity while a new market is discovered and plans to put the asset back into service are solidified.
In 2018, a major global energy company turned to the pipeline experts at HT Engineering to help engineer and plan the nitrogen displacement (purge) and idling of an underutilized 525-mile high-value refined product pipeline. HT Engineering worked closely with the company project manager to synthesize requirements from management, technical, and operations stakeholders and develop an execution plan that provided the company’s management with confidence that the project could be completed safely.
I was extremely impressed with the quality, level of support, professionalism and agility that HT Engineering provided for my project. I continue to look for opportunities to leverage HT Engineering’s capabilities.
During the planning process, HT Engineering built a hydraulic model to calculate the product and nitrogen flow rates and pressures required to displace the product from the line and leave it packed with nitrogen. The pipeline, which traversed significant elevation changes, had multiple pump stations and was divided into several piggable segments. The model allowed the team to optimize nitrogen injection locations, plan pump and control valve operations, and verify that pressures and displacement pig speeds could be kept within acceptable ranges for the purge of each segment.
In addition to the execution plan, HT Engineering worked with the local operations personnel and the project’s contractors to develop detailed work procedures and facility schematics that guided the team step by step through each of the purge operations. After each operation, HT Engineering captured lessons learned and updated the subsequent procedures accordingly, allowing the team to improve its performance as the project progressed.
While the team conducted the purge operations, HT Engineering worked on site supporting the company’s project manager and purge manager by tracking procedure completion and monitoring operating conditions. By watching and analyzing the nitrogen and product flow rates, line pressures, and pig location and speed HT Engineering was able to provide the managers the information and recommendations they needed to run the operations safely and recognize emerging problems quickly.
One such problem occurred when a deviation from the procedure allowed nitrogen to bypass the pig during a receiving operation. The bypassed nitrogen caused a vapor lock and stalled the purge of the next segment. HT Engineering helped the company’s subject matter expert diagnose the problem, analyzed the data to gain a clear understanding of the situation, and designed a solution that allowed the team to remove the bypassed nitrogen and get the project back on track.
Ultimately, the company’s project was successful with 183,000 bbls of valuable product delivered and 525 miles of pipeline safely idled and ready for the next chapter of profitable service.
As the Project Manger for this pipeline purge project, I was in great need of reliable and responsive all-around engineering support. Second to absolute safety, this project was schedule driven which put additional pressure on the team to deliver complex and detailed procedures for execution. HT Engineering’s role in the project was key to produce hydraulic calculations, form execution strategies then translate these strategies into detailed procedures and finally function in the field real-time as the project’s purge control center.
HT Engineering gathered all inputs and created hydraulic calculations for the 525-mile pipeline. As the model was built and calibrated, it was a key tool to create different execution strategies and outline the constraints for each option which was essential to evaluate and ultimately finalize the execution strategy to purge the pipeline. Later in the project, when the purge pigs stalled from vapor lock, the hydraulic model, assumptions and calibration were put to the test to reverse engineer the potential location of the stalled pigs so that crews could excavate and use NDE methods to confirm pig locations. These hydraulic calculations were also essential in the production of bid documents (also produced by HT Engineering) for the Nitrogen Vendor.
HT Engineering’s support to produce the execution strategies consisted of utilizing the hydraulic calculations to define nitrogen injection locations, purging durations and nitrogen volumes required. They also created schematics for each location along the pipeline that required mechanical modifications. Ultimately HT Engineering produced Construction SOW documents accordingly for the finalized execution strategies.
HT Engineering then meticulously produced the detailed procedures which were heavily reviewed by the project team, Operations and SME’s. Very little comments were gathered during the intensive safety, risk and operations reviews which speaks to the competency and diligence from the HT Engineering team. As described, Lessons Learned were discussed, captured by HT Engineering, then incorporated into the procedures for upcoming pipeline segments.
Once it was time to mobilize and begin execution of the purge, HT Engineering provided purge tracking tools and the personnel to effectively create a project Purge Control Center which continuously communicated and coordinated with the Operations Control Center for the purge and tracking of pigs around the clock (24hrs) while purging was taking place. This support was essential to the project combining all of the front-end loading into the actual execution of the purge. Later, when the project ran into issues with the stalled vapor locked pigs, HT’s support as the Purge Control Center was key to help find the stalled pigs and ultimately retrieve to continue purging activities. Although purging schedules changed throughout the months of execution, HT Engineering was always able to provide onsite field support as requested which greatly aided in managing schedule constraints when scheduling purges. This included both day and night shifts to provide 24hr coverage during purge activities.
Lastly, HT Engineering was the keeper of the procedures and documentation which were heavily relied on to reverse engineer the root cause of the stalled pigs and gather lessons learned for each completed segment. Many of these documents are now used in other projects as templates and examples of “what good looks like”.
From the Project Manager’s view, having a consultant produce the hydraulics, strategy analysis support, bid documents, detailed procedures, onsite real-time tracking and wrap-up documentation is in-valuable. I was extremely impressed with the quality, level of support, professionalism and agility that HT Engineering provided for my project. I continue to look for opportunities to leverage HT Engineering’s capabilities for my projects.