Oil and gas pipelines in North America have been in use for well over 100 years, and some of these early constructed pipelines are still in service today. Although many early pipelines were made of wood, over the past few decades majority of pipelines are constructed with steel. Despite its high strength, steel has a propensity to dent, buckle, corrode or crack when expose, all risks to the integrity of a pipeline. In order to identify defects, proactive pipeline inspections are necessary to avoid failures, leaks or ruptures. One way of validating pipeline integrity is the use of Direct Assessment.
Direct assessment is a structured, iterative integrity assessment protocol used by pipeline operators to assess and evaluate pipeline integrity. There are three types of anomalies specifically identified by DA: External Corrosion (EDCA and ECCDA), internal corrosion (dry gas, wet gas, and liquid petroleum ICDA), and stress corrosion cracking (SCCDA). The ability to detect geotechnical dent and buckle threats using Pipe Wall Assessment (PWA) technology on above-ground inspection platforms is an emerging technology that many operators are using as either a screening tool or in conjunction with other methods.
Spectrum XLI was specifically developed to efficiently access pipelines that cannot accept ILI tools. ECDA and ECCDA projects include pipeline mapping with highly accurate GPS and depth of cover information. XLI uses soil resistivity measurements to assess the Corrosivity of the soil relative to the pipeline. Although this is not a mandatory requirement for indirect inspection per the NACE ECDA process, XLI integrates soil resistivity to assess the severity of corrosion on the pipeline with greater accuracy and confidence – allowing operators to go above and beyond the requirements when completing ECDA and ECCDA.
PureHM’s Spectrum XLI system employs advanced survey techniques which offer redundancy. Unlike conventional above ground inspections, XLI collects multiple sources of data at one time. This means Spectrum XLI will collect GPS/GIS, depth of cover, depth of water, gas leak detection, CP CIPS, direct current voltage gradient (DCVG), alternating current voltage gradient (ACVG), alternating current-current attenuation (ACCA) and soil Corrosivity measurements. Not only does Spectrum XLI collect these data points, the quality of the data is unmatched. Where GPS is unavailable, XLI utilizes inertial mapping to continuously map the pipeline, something that legacy systems do not offer.
The complete XLI system goes above and beyond conventional techniques to deliver reliable data to pipeline operators in order to make more informed decisions regarding their pipelines integrity. PureHM has completed more than 16,000 kilometers (10,000 miles) of above-ground pipeline inspection, and thousands of water crossing surveys. This has helped operators across North America prevent problems on their pipelines and provide assurance to their stakeholders that they are using the most reliable survey technologies available.