Networked Automatic Monitoring Pipeline System (NAMPS)
Monitoring and maintenance costs of the pipeline structures exceed the original installation of the pipelines. More importantly, it is extremely dangerous since it requires hand inspection in harsh and hazardous environments. During winter months, in addition to complete darkness, temperatures can drop well below freezing with high winds and snow.
Most failures of pipelines are localized to the weld joints of the pipe. Leakage of failed pipelines is dangerous and costly to the population, the environment, and the energy company. The Trans-Siberian Oil Pipeline typically releases 5 to 7% each year; in 1991 alone that amount to about 7 million barrels. Recently, a corroded pipeline spilled roughly 100,000 gallons of crude oil and saltwater onto the Alaskan tundra. Although a crew plugged the leak in 12 minutes, it endangered the crew's lives and polluted a large area. Recently, pipelines have become targets for terrorist activities.
Sadly, due to the state of the pipelines, maintenance is often performed after a leak occurs. Pipeline companies must rely on indiscriminant replacement of pipes or the pipeline situated in harsh climate areas must be frequently inspected by hand. This is very risky activity and prone to operator error. Alternatively, pigs are used to inspect the interior of the pipes, but this technology provides only sporadic information and requires stopping or re-routing of the oil flow. Additionally, pigs require constant maintenance and on-site monitoring.
The Johns Hopkins Applied Physics Laboratory is proposing a non-intrusive measuring system that will provide data to determine the occurrence of leakage or third party damage by monitoring the health of the pipe. This system, the Networked Automatic Monitoring Pipeline System (NAMPS), is easily installed, requires no wiring, and is low cost since it is built on 'commercial-off-the-shelf' (COTS) components.
Utilizing the NAMPS will allow pipeline companies to only replace sections of pipe that need to be fixed rather than indiscriminant renovation. This will reduce overall upkeep costs by allowing maintenance to be scheduled and performed at the discretion of the pipeline company. Thus, repair crews can provide proactive preventative maintenance during safer conditions rather than reactive repairs and cleanup.
Since the system can be monitored from either a passing vehicle or via the network, in-situ inspections can be reduced. This would save manpower and reduce the risk during inspections, particularly in extreme conditions. Since pipelines could be more closely monitored for corrosion and third party damage, the likelihood of leakage is substantially reduced. This would benefit both the population and the environment surrounding the pipeline areas.
The envisioned assembly consists of a 'belt' of sensors strapped and tightly cinched to insure direct contact to the pipeline. At each belt 'rung' or crossing joint, a strain gauge is placed. The crossing joints are positioned about 3" apart around the circumference of the weld of the pipeline. A microcontroller accompanies the strain gauge to process data and provide temperature data. Thus, on a 4' diameter pipe, 50 controller/strain gauge crossing joints are placed around the weld joint. At the bottom, or base of the belt is another microcontroller, which supports vibration, acoustic, and vapor sensors, as well as the communications interface. Commercial implementation could utilize VLSI to compact the design into a single chip.
Power to the system is provided using thermopiles adapted to high heat fluxes (10W/cm2). Many are in artic areas where the ambient temperature is substantially lower than the temperature of the crude oil (150 degrees F). On the Trans-Alaskan pipeline, crude oil is generally piped at 150 degrees F, well above the ambient temperature of the environment, which at it's highest averages 72 degrees F at Fairbanks on the 1000 mile Alaskan pipeline. Temperatures are lower on the Trans-Siberian. Likewise, crude transported in pipelines in desert regions is superheated (450 degress F) to increase flow rates providing a substantial temperature differential. Substantial work has been performed for the U. S. Army regarding thermopiles micropower systems utilizing the thermal differences of the pipeline and the liquid being carried. Each sensor's power will be cycled to maintain low power; as are the communications, control, and signal conditioning circuitry.
Patent Status: U.S. patent(s) 6834556 issued.CONTACT:
Mr. K. Chao
Phone: (443) 778-7927