Every day, oil, natural gas, refined products, chemicals, water, CO2, and other commodities are transported via massive transmission pipeline systems. Products move from production fields and refineries, through terminals, pumping and compressor stations and hubs, and from there, to waiting tank farms, petrochemical plants and end-user markets. To ensure safe and reliable transmission operations, pipeline inspection and integrity management (IM) programs have been developed, along with state-of-the-art supporting technologies for capturing and analyzing the resultant data.
Most of these new technologies were developed for inter- and intrastate transmission pipeline systems comprised of large-diameter pipelines with built-in pig launchers and receivers. As a result, compressor stations, product terminals and tank farms have been somewhat left out of the loop. Highly congested terminal and station facilities that include small-diameter pipeline systems can make typical IM programs difficult to implement. Yet, many terminals, stations and tank farms include vintage equipment and aging infrastructure in desperate need of evaluation and remediation.
Hydrotest, Ultrasonic Inspection, and Replacement Issues
Until recently, station and terminal operators had few choices of inspection methods. Typically, terminal and station facility pipelines were considered to be too small to be piggable. Low-tech evaluation methods such as low-pressure hydrotesting and ultrasonic readings were commonly used, but these methods brought their own set of challenges.