Laser Scanning Enables Fast-Track Design and Construction of Natural Gas Plant Modification
Fitting a large de-ethanizer vessel into a tight space is no problem with the right technology.
Processing natural gas requires meticulous engineering, especially when it comes to managing the associated hydrocarbons, such as ethane. Originally considered a waste byproduct, ethane has found use in plastics and petrochemicals, making it an increasingly valuable commodity. Effectively capturing the ethane for downstream use, however, requires additional vessels for production, transfer and storage—a challenging proposition considering the already congested layout of many natural gas processing plants.
When Williams decided to add a 150,000 gallon de-ethanizer to its Oak Grove, WV, natural gas processing plant midway through the plant’s construction in 2015, the challenge was threefold: 1) The congested layout of the plant would have to be modified to accommodate the large de-ethanizer system; 2) no legacy or as-built information was available to design the new tank facility; and 3) the new system would need to be installed in an extremely tight time frame of just four days, leaving no room for error.
Williams trusted only one engineering firm to handle the job. Borton-Lawson, based in Wilkes-Barre, PA, had been a reliable partner for years, and the firm’s technology investments kept it on the leading edge. In 2013, Borton-Lawson had substantially boosted its complex engineering capabilities with the addition of a Leica ScanStation laser scanner and Cyclone point cloud processing software. The firm’s ability to quickly and comprehensively capture accurate as-built data on the existing space would be imperative to meeting the project goals. “Accuracy was critical,” said James Kovalik, PLS, technology manager for Borton-Lawson. “Laser scanning with the Leica ScanStation was the only way to accomplish the task.”
The accuracy of the scans allowed Borton Lawson to thoroughly explore the proposed design with Williams’ engineering, safety, and operations teams.
Speed, Safety and Accuracy Pay Off
Of course, retrofitting a natural gas plant can be done without laser scanning. The traditional approach relies on using lifts and ladders to obtain hand measurements and makes assumptions based on perfect real-world conditions. The process is laborious, risky and prone to error, leaving much to be desired. Obtaining the necessary field surveys and documentation typically requires multiple costly site visits over a period of weeks, and measurements must be double and triple checked to ensure accuracy.
In contrast, Kovalik spent just 10 hours onsite with the Leica ScanStation C10 (the firm has since upgraded to a Leica ScanStation P40) and quickly collected comprehensive and accurate as-built documentation of all necessary piping, tanks, valves, structural and electrical components, and site features associated with the project area. “By utilizing the 3D scanning approach, the design team was able to replicate the as-built conditions accurately in a 3D model,” Kovalik said. “The Leica ScanStation saved countless site visits, as well as time and costs associated with traditional field surveys and documenting.”
Back in the office, the Borton-Lawson team processed the point clouds with Leica Cyclone software and easily exported the data into its modeling and design software. The accuracy of the scans allowed Borton Lawson to thoroughly explore the proposed design with Williams’ engineering, safety, and operations teams to jointly understand how all facets of construction would impact existing operations prior to actual construction taking place. “With 3D laser scanning, the project team was able to thoroughly review construction issues and conflicts prior to actual physical construction, which simplified the construction phase and minimized the risks of unexpected changes and downtime,” Kovalik said. “Having the accurate 3D data also streamlined construction by reducing RFIs [requests for information] from the contractor.”
Point Clouds Provide a Perfect Installation
Transporting the 123-foot-long, 14-foot-wide de-ethanizer by rail from Houston, TX to a rail yard along the Ohio River and then by “superload” truck the final 30 miles to the Oak Grove plant was a complicated endeavor that required careful coordination among multiple agencies and organizations along the way. Stakeholders undoubtedly monitored the move with more than a little anxiety, considering the rolling shutdowns that would be required on roadways and the need to temporarily raise some of the utility lines to accommodate the last leg of the journey. One thing they didn’t need to worry about, though, was the installation of the de-ethanizer once it arrived safely in Oak Grove. Thanks to the innovative approach used by Borton-Lawson with 3D laser scanning, the installation onsite was flawless.
No room for error: The 150,000 gallon de-ethanizer had to fit precisely in plant’s congested layout.
“The project was completed within the planned schedule and budget, and, most importantly, without interrupting the existing production or processing capabilities,” Kovalik said. “Through careful planning and design of the proposed facility, as well as extensive collaboration with their engineering team by using the Leica ScanStation, we were able to meet Williams’ needs and achieve a successful installation.”