The recent Santa Barbara, CA oil spill is yet another example of the need to monitor and control pipelines to prevent breaches that could endanger life and property for hundreds of miles overland and along coastlines. According to the Los Angeles News Group, the spill of more than 100,000 gallons of oil resulted from the failure of monitoring equipment to detect leaks in a corroded pipeline and to automatically shut off valves supplying the oil.
To protect infrastructure against such disasters, promote worker safety and facilitate automated functions ranging from drilling to wellhead operation and transport pipelines, oil and gas operators are increasingly turning to fibre optic cable suppliers for “end-to-end” communications and control solutions. Many such solutions include ruggedized cable and connectors that ensure survival of fibre-based DCS/PLC automation/control architectures for onshore and offshore oil and gas operations, even in the harshest environments.
Integrating the DIN rail enclosure
As fibre optic cable emerges as the medium of choice in many industrial arenas, the DIN rail enclosure plays an increasingly important role. Mounted to a standard DIN rail – the metal rail used to mount various electrical components (e.g., terminal blocks, motor starters, circuit breakers) in a control cabinet – a DIN rail enclosure provides a central location where external and internal wiring can be connected quickly and efficiently.
“This type of enclosure is ideal for production applications, the industrial automation side of businesses,” says Stephen Porach, PE, RCDD, Sr. Manager of business development, Enterprise Solutions, at Optical Cable Corporation (OCC).
“Today the oil and gas industry is turning from highly proprietary communications systems to the more enterprise wide prevalent Ethernet communications protocol via fibre optical cable. The appropriate DIN rail enclosure provides an optimal connection for fibre cable that can be terminated in a fixed position.”
Porach explains that the Ethernet protocol allows products from various manufacturers to talk to one another, making the system less proprietary and costly. Also, fibre cable won’t cause an electrical spark, another advantage that makes it ideal for many oil and gas applications, particularly in the field.
Porach adds that OCC has developed a new, ruggedized line of DIN rail enclosures to provide highly secure terminations within a wide variety of industrial applications even in the most adverse environmental conditions. Available for both fibre optic and copper applications, this type of enclosure is very easy to install and provides very simple patching for the connection of all those automation components in a patch field for the industrial automation environment.
This enclosure can also be ordered as a complete assembly including connectors and fibre optic cables that are pre-terminated at the factory. These assemblies are built according specifications that will meet the environmental demands of any application – whether noise from electric motors, highly flammable conditions or extreme temperatures – thereby providing a highly reliable, integrated DIN rail solution.
“Companies in the oil and gas industry are placing this enclosure into a cabinet located in the automated ‘driller’s cabin’ on their rigs, where one person monitors drilling controls, automated pipe handling controls, computer hardware and data processing systems in single room on the rig,” says Phillip Hoyle, OCC Business Development Specialist. “From there they’ll connect them to the HMIs and PLCs and other systems. Typically the enclosure would be placed next to the PLC, and then has a 6-, 12- or 24-fibre connection there.”
Hoyle adds that there is high interest in this type of DIN rail enclosure among refineries and petrochemical plants.
“They are bringing in pre-terminated MTP assemblies and connecting a 12-channel MTP into a closet so they can break out their connections to PLCs that continuously monitor the state of input devices,” Hoyle explains.
End-to-end reliability needed
With or without a DIN rail enclosure termination, fibre optic cable systems for the oil and gas industry must often include ruggedized or even military-grade cable and connectors.
“Typically, in the oil fields our customers select an armor-based cable,” says Hoyle. “This type of cable is designed specifically for extreme environmental conditions- temperature, humidity, ice, fungus, and fluid immersion. The cable contains MIL (military grade) type of fibre, which has a bronze braid and is double-jacketed. This top jacket may be a flame-retardant or a low-smoke, zero halogen jacket.”
This type of cable is designed to provide extra protection when you’re out in the oil field in an area where heavy objects may be dropped on cables, or there is danger of the cable becoming sliced or nicked by sharp surfaces.
For pipeline applications, where sensing and communications capabilities are critical, oil and gas companies are increasingly deploying ruggedized fibre optic cable and DIN rail enclosures to interface with communications devices.
“This enclosure is an ideal way to interface with communications devices that are interfacing with other communications devices,” Hoyle explains. “You can run a fibre cable and have it break out at a point, a communications pod, for example, then bring the fibre in and have it split off to some communications devices and then go back out with the cable.”
As far as pipeline cable is concerned, it is normally tough enough to withstand temperature extremes and/or heavy moisture.
If vermin such as rodents are a concern, there are fibre cables that provide suitable protection; for example, OCC offers ruggedized cables with a layer of fibreglass protection underneath the outer jacket. When a rodent starts chewing on the cable, the fibreglass starts to splinter in its mouth and cause the animals back off.
In addition to having fibre optic cable with appropriate protection, oil and gas producers need to have cable connectors and adapters that can withstand temperature extremes and many types of stresses, enabling systems to run and data to flow regardless of the harshness of the environment.
Military-grade connectors and adapters may be required for some applications. These products feature non-optical disconnect, black anodized brass or stainless steel configurations that can withstand extreme temperature change, shock, vibration and corrosion.
“Selecting the right fibre cable and connectors often requires a consultative process between customer and supplier,” explains Hoyle.
“In our case, business development specialists like me will consult with an engineer, project manager or application specialist within the customer’s team. We’ll usually talk through the application and surrounding requirements. The next step is to provide a quote for the application, and review it step by step with the customer. In some cases we may provide the customer with a prototype or sample for testing processes. But whatever the solution, it is vital to ensure that it is end-to- end.”