In-line inspections (ILI) are a primary, often preferred, method for identifying corrosion defects that could eventually lead to costly, unintentional pipeline failure. However, operators have been unable to perform these inspections on a third of the world’s installed transmission pipelines – some 540,000 km – because the pipelines were not originally designed to accommodate the passage of in-line tools. As a result, operators have been limited to either using less-quantitative techniques (such as direct assessment or hydrotesting methods) or having to perform substantially more expensive pipeline modifications.
A pipeline is deemed unpiggable if conventional in-line inspection tools (smart pigs) are unable to inspect a given line due to valve restrictions, multiple pipeline diameters or too many sharp radius bends. This is where GE’s first generation of SmartScan tools, a new family of advanced, in-line-inspection tools available to both liquid and gas pipeline operators, come in. SmartScan’s innovative collapsible structure and unique sensor design, coupled with an innovative hot-tap launch system, are key elements of the system developed to overcome such obstacles. While future SmartScan models will be self-propelled by robotic carrier, the initial SmartScan tool relies on the flow of the pipelines for propulsion. These innovations will offer operators a cost effective alternative to pipeline modifications, without interruption of service.
SmartScan’s ability to navigate both back-to-back tight bends and multi-diameter pipe sections was successfully demonstrated to a group of gas and liquid pipeline operators in early 2005. El Paso Corp. of Texas, the largest natural gas pipeline operator in the US, became GE’s first customer to commercially deploy and evaluate SmartScan during an inspection of a southern US segment of El Paso’s vast pipeline network.
“GE’s SmartScan tool represents a significant, game-changing development for the oil and gas industry,” said Claudi Santiago, President of GE’s Oil & Gas business based in Florence, Italy. “It is the first product that can help operators begin to address one of their most persistent problems.”
Operators have the option to launch and receive SmartScan without the need for conventional traps, via the use of GE’s temporary insertion method. With this approach, a permanent 45° hot tap fitting is installed on the pipeline without interrupting service, and the cleaning and inspection tools are launched through a retractable chute. The angled hot-tap fixture remains as part of the pipeline, providing easy access for continuing inspection and cleaning requirements.
SmartScan was a cooperative effort developed by GE’s various global pipeline services teams. Mechanical design was developed in Toronto, Canada, electronics in Karlsruhe, Germany, magnetics and proofing in Newcastle, England, ancillary systems and testing in Houston, Texas, with project management provided from Karlsruhe and Houston.
The first model’s flexible structure allows it to navigate pipeline diameter variations of between 16-20, 20-26 and 24-30 inches. Future generations of SmartScan will address different business niches by navigating additional larger and smaller diameter ranges, as well as lines without product flow or those in a distribution network.
Industry and US Department of Energy (DoE) efforts are underway to develop robotic carriers capable of traversing pipelines. However, much work remains to be done in order to fully develop the ILI sensor payloads and necessary ancillary services. Although it will likely take several years for robotic platforms to be ready for commercial deployment, their availability can be relied on to address the remaining unpiggable segments in advance of looming 2012 regulatory requirements in the United States.
SmartScan is the latest in GE’s growing portfolio of products and services that offer innovative, cost-effective solutions for achieving improved pipeline integrity.