ADMA OPCO focused on identifying hidden risks in aging pipelines using long range ultrasonic testing (LRUT). LRUT employs low frequency guided waves to detect discontinuities like corrosion under insulation. This non-destructive testing technique was validated to detect all defects greater than 3.5% cross sectional loss. LRUT inspections of pipelines at ADMA-OPCO provided near 100% coverage to understand pipeline health and ensure integrity. The results from LRUT surveys reliably informed remaining life calculations and health assessments of difficult to access pipelines. LRUT allowed more frequent inspections than conventional methods as it requires exposing only small sections of pipe without shutdowns.

1. ADMA OPCO Focuses on Identifying the Hidden Risks and
Improved Technologies for Piping and Pipeline Inspection Using
Long Range Ultrasonic Technique
Authors:
Talal Al-Sayed, Brian Balmer, Tarek A. Hassan, Mohamed Al Ansari, Malik Raji, Gary Penney
Abstract
Title: Understanding Hidden Risk of Ageing Pipelines
ADMA-OPCO has been in operation for more than 50 years, with the majority of its facilities
ageing and in most cases, exceeded their original design life. A major concern with aging
facilities is maintaining the equipment fitness for service and avoiding any sudden failures,
which can have significant HSE consequences. Difficult to access piping and pipelines in
DAS were, one such challenge overcome by a strategic approach built around the
application of advanced long range ultrasonic testing.
Long-Range Ultrasonic Testing (LRUT) is an advanced Non- Destructive Testing using
ultrasonic guided waves. LRUT employs low frequency guided waves, operating just above
the audible range, propagated from a ring of transducers fixed around the pipe. Propagation
of these guided waves is governed principally by frequency of the wave and thickness of the
material. Wherever the wave encounters a change in pipe wall thickness (whether an
increase or a decrease), a proportion of energy is reflected back to the transducers, thereby
providing a mechanism for detection of discontinuities. LRUT has recently been
independently validated to detect all defects greater than 3.5% Cross Sectional Loss in a
CUI application.
The LRUT technique was initially developed for detecting Corrosion under Insulation (CUI)
for piping in petrochemical plant, utilizing this technique to inspect the piping and pipelines in
DAS, including flare lines was a revolutionary idea which enabled ADMA-OPCO to
understand the health of these lines and to ensure their integrity for future production
requirements. The implementation of Advanced NDT Inspection techniques (LRUT, SRUT
and 3D Tool) for the first time in ADMA-OPCO, to complement standard NDT Inspection,
coupled with Risk Based Condition Assessment of the Das Island piping systems,
incorporates an innovative, improved, efficient and effective approach of damage
mechanism identification, defect and hidden risk detection and evaluation. This information
is the utilised to enable appropriate and optimized mitigating actions to be put in place in a
timely manner.
Remaining life calculation based on LRUT survey was found reliable and accurate and is
helpful for health assessment of difficult to access piping. Inspections can be carried out
more frequently with LRUT because pipes do not have to be dug up completely, only a small
section need to be exposed, no shut down required, on average 60m of pipe can be
inspected from one location, internal and external corrosion are detected simultaneously on
complete pipe circumference providing near 100% coverage of the pipe wall.