Regulatory frameworks and industry standards designate hydrostatic testing, in-line inspection (ILI), and direct assessment (DA) as the accepted methods for evaluating pipeline integrity. They further permit the deployment of alternative technologies, provided these can demonstrate an equivalent capability to deliver the same level of understanding of pipeline condition as the established or accepted methods. In line with this framework, Petroleum Development Oman has conducted field trials of alternative inspection methods to qualify their applicability for buried non-piggable (Difficult to inspect) pipelines. The objective is to present trial results, lessons learned, and proposed qualification criteria for three tested technologies: Guided Waves, Metal Magnetic Memory (MMM), and Acoustic Emission (AE). To qualify alternative technologies, it is essential to first understand the type of insights provided by the currently accepted methods and then establish objective criteria against which new candidates can be tested. The recognized methods provide the following integrity information:
•hydrostatic testing (HT): Assesses the strength of damaged areas. Any substitute technology must reliably evaluate (directly or indirectly) the line’s structural strength along its full length.
•In-line Inspection (ILI): Provides characterization of anomalies. Any alternative must scan the entire pipe wall volume and demonstrate equivalent capability to detect, identify, and size anomalies with reliability comparable to ILI.
• Direct Assessment (DA): Identifies the pipeline’s weakest conditions. A substitute methodology must follow the same principle analytically or physically identifying the most critical locations, directly examining them, and conducting FFS evaluation of the line.
In this work, we present Petroleum Development Oman’s trials on alternative inspection technologies, covering evaluation results, segment selection, and success criteria. To define these criteria, Metal Magnetic Memory (MMM) was considered as a potential substitute for pressure testing, while Eddy Current, GW, and (AE) were evaluated as candidates to replace or complement ILI and DA, depending on the implementation approach.