
In Line Inspection (ILI)
GTS has extensive experience in the project management of In-Line Inspection (ILI) projects for gas transmission pipelines. GTS has managed over (50) individual ILI projects since 2014. These projects range from Non-Traditional inspections that can vary from a few hundred feet to a few miles, to Traditional inspections covering thousands of miles of transmission pipeline. GTS has detailed knowledge of not only the project management of In Line Inspections but also has the comprehension of the necessary details and resource requirements needed to successfully complete a thorough inspection.
Traditional In-Line Inspection
GTS provides comprehensive start-to-finish consulting, project management, and engineering services for gas utility In-Line Inspection (ILI) pipeline projects. The GTS Project Management team understands the needs and challenges when performing an in-line inspection and has relationships with many vendors in North America. We have the knowledge and experience required to provide support in tool selection criteria, ILI upgrade requirements, pressure and flow requirements, outage coordination, and other important aspects of ILI inspections that can help provide a positive ILI project outcome.
Non-Traditional ILI
Similar to the Traditional In-Line inspection services, GTS also provides comprehensive Project Management for inspecting pipeline segments previously considered unpiggable with Non-Traditional ILI (NT-ILI) methods and technologies. Our staff bridges the gap between transmission pipeline operators and NT-ILI tool vendors through understanding of various tool types and execution methods available today. The GTS NT-ILI team is skilled in evaluating each specific situation, identifying the most effective and efficient solution, developing a project plan that enables execution of the work, providing field support to oversee the assessment activity and delivery of final assessment results.
Please refer to our “Key Projects” section below for various project examples that highlight GTS’ expertise.
Key Projects

Casing & Inserted Pipe Inspection Program Using Robotic ILI
GTS scoped and project managed ten (10) non-traditional ILI projects as part of an overall program to inspect 24 cased and inserted pipeline segments between the San Francisco International Airport and Downtown San Francisco. Robotic ILI was utilized due to the low MAOP of the pipeline, as well as frequent diameter changes, restrictive pipeline features, and a dense urban and environmentally sensitive area. Planning and execution challenges encountered and overcome included tool damage, scope expansions, permitting through six (6) agencies including the Federal Aviation Administration (FAA), unmarked underground utilities, and immediate anomaly discovery and response.
A total of fifteen (15) excavations, installation of eight (8) Pressure Control Fittings, and two cut-outs were required to complete the final scope of work. Upon completion, the program successfully inspected all targeted casings, one water crossing, and a total of 12,494 feet of 20” and 24” OD pipe. All inspections were completed in advance of the program deadline.

Tethered Robotic EMAT Inspection of Casing Executed in Six Days
After construction mobilization to conduct an External Corrosion Direct Assessment (ECDA) casing assessment, the project was halted due to a change in permit conditions. Once updated permit requirements were confirmed, it became evident that completing the casing inspection would be infeasible by the required compliance deadline.
GTS evaluated the viability of planning and executing a non-traditional ILI within the required timeframe, determined it viable, and assigned a team of project managers to coordinate the effort. Pipeline shutdown and construction resources were coordinated from multiple groups, including working with adjacent in-progress projects, and GTS worked closely with the robotic ILI vendor who was able to mobilize on short-notice. The casing was successfully inspected and the ILI run accepted as planned by the project management team. The entire project, from inception to completion, was completed in six days’ time and met the inspection compliance deadline.