Ethernet Convergence in Mobile Oil and Gas Mike Werning Field Application Engineer, Moxa Americas
Overview The increase of activity in the oil and gas market in North America is driving change in the way mobile systems are deployed. As drilling in the US increases, there is also a great need for mobile services such as well monitoring and stimulation. The equipment used for these applications is typically designed into a truck or trailer, or mounted on a mobile skid that allows the systems to be moved from site to site as needed. The technologies that allow these systems to communicate with each other are undergoing a change. Systems that formerly used serial fieldbus protocols are now being redesigned in favor of their Ethernet-based equivalents. Another trend is the move from wired to wireless network infrastructures, which gives operators the convenience of simpler deployment and takedown when equipment is moved from site to site. Remote Management and Safety Systems used in pumping and well stimulation applications use pumps, blenders, valves, HMIs, PLCs, and other related devices that are controlled and monitored using industrial fieldbus protocols and SCADA software. In the past, these systems were hard wired together with an operator running each machine locally. Now there is a trend to remotely manage the operation to both increase safety and improve operational efficiency. The operation of the system can now be managed from a data van, adding to the safety of the operator. However, the data van solution brings with it some challenges, primary of which is getting all the data from the remote vehicles to the data van in a reliable manner. Systems designers must use a number of technologies to make these systems operate reliably. The technology must be designed and tested to meet tough industrial standards to survive the harsh conditions, and since all of the networking equipment is in a potentially flammable zone, it typically must be rated to ATEX class 1 div 2. The ability to withstand temperature extremes and to survive in a high vibration environment is also required. Commercial grade equipment simply won t survive. Figure 1: Industry Specific Certifications for Explosive Environments Released on October 27, 2014 All rights reserved. Moxa is a leading manufacturer of industrial networking, computing, and automation solutions. With over 25 years of industry experience, Moxa has connected more than 30 million devices worldwide and has a distribution and service network that reaches customers in more than 70 countries. Moxa delivers lasting business value by empowering industry with reliable networks and sincere service for automation systems. Information about Moxa s solutions is available at www.moxa.com. You may also contact Moxa by email at info@moxa.com. How to contact Moxa Tel: 1-714-528-6777 Fax: 1-714-528-6778 1
Ethernet Convergence In order to take advantage of high speed networks, these systems are moving in some circumstances from serial fieldbus protocols to Ethernet protocols, such as EtherNet/IP or Modbus/TCP. Companies making the transition have taken a multistep approach. The first step was to become operational over wired Ethernet using heavy duty military grade fiber optics to create a network interconnecting between vehicles. While providing highly reliable communications, since cables tend to wear out in this kind of rough environment, companies are seeking alternatives to the wired communication option. Figure 2: Datavan connected to remote vehicles with fiber optics We are currently seeing a move to wireless technology through the use of IEEE 802.11, which brings with it a tremendous cost savings. The main advantage is in the simplicity of pulling the vehicles to a site and having the network up and operational upon power up. When the job is done, the vehicles can pack up and pull away without needing to worry about taking down the network infrastructure. Figure 3: Datavan connected to remote vehicles using wireless technology 2
The Need for Fieldbus Gateways Many different industrial fieldbus devices are in use today on remote vehicles and skids. For a variety of reasons, these devices remain serial based, which means that in order to make them work over today s Ethernet networks, protocol converters are required. Serial-to-Ethernet converters or gateways are being used to interface to meters, valves, controllers, and HMIs that use serial fieldbus technologies such as Modbus and Profibus. These gateways translate from Ethernet-based protocols such as Modbus/TCP to serial-based protocols such as Modbus on the serial side. In order to accommodate multiple gateways and other Ethernet-based devices, depending on the number of devices that need to be interconnected on each vehicle, layer two switches may also be required. Figure 4: Example of Modbus/TCP to Modbus Serial Gateway Wireless Technology Systems designers are also looking to use wireless technologies for a number of reasons. The flexibility of placement of the vehicles, and the reduced cost and elimination of cabling between the vehicles are key motivations for the adoption of this technology. This provides options to their customers to offer wireless connectivity in areas which may be difficult to wire. System designers are taking systems that work well on wired infrastructures and are adapting them to work over wireless infrastructures, and consequently they are looking for wireless networks that offer low latency and high throughput. For remote connectivity, IEEE 802.11 technologies are being used to provide wireless access in the local area. Many companies are just now making the move to industrial wireless and are becoming aware of the options available to them. For example, the use of fast roaming for mobile applications, and wireless redundancy through the use of dual radio technology. In addition, there are choices of frequency band, channel width, and encoding technology that impact the overall throughput of the system. These must be carefully planned for success when using this technology. Many operators have chosen to work with an integrator to help them through this process to ensure success. In some cases, reliability and redundancy are of great concern. In order to accommodate this need in a wireless implementation, a dual radio technology such as Moxa s zero packet loss redundant radio can be utilized. This approach uses two different radio channels to provide replicated packet data. Using this approach, interference on one channel 3
does not affect the other channel so that the packet sent on the unaffected channel still gets through. This technology is now available in the AWK-5232 and AWK-6232 redundant 802.11n radio products. Figure 5: Wireless redundancy with Moxa dual radio solutions Security and Network Address Translation Security is always a concern with any industrial control system. In order to isolate the layer 3 networks on the remote vehicles and also limit the exposure of the control systems to the outside world, network address translation NAT can be utilized. Network address translation allows the designer to use the same IP addressing scheme for the devices on each vehicle or skid. NAT greatly simplifies the IP addressing scheme and allows these vehicles to be intermixed from site to site. NAT also simplifies replacement and maintenance procedures. Devices on each vehicle or skid can be assigned fixed IP addresses based on the port they are plugged into making field replacement a simple task. A router like the Moxa EDR-810 is a perfect fit for this application. It is capable of providing network address translations, a firewall, and can also assign IP addresses on a per port basis. Since the EDR-810 has ten switched Ethernet ports, in some cases another layer 2 switch is not required on the remote vehicles, resulting in additional cost savings for the overall design. EDR-810 NAT & Firewall Port Forwarding NAT Radio gets IP via remote DHCP server AWK-3121 Client Radio EDR WAN IP via AP DHCP server LAN Devices Static IP per port: 10.0.0.1 PLC 10.0.0.2 HMI 10.0.0.3 Modbus 10.0.0.4 Valve, etc Assign these ports to LAN Figure 6: EDR-810 Secure L2 Switch/Router allows each vehicle/skid to have identical local addressing 4
Site Security and Process Monitoring Site surveillance for both process surveillance and site security is a major concern. With the operator now in the data van, there can be requirements to provide visual feedback to the operator to maintain visual status of the mixing process through the use of IP cameras. For example a process may involve the mixing of sand and other chemicals in a hopper. The use of cameras can ensure that the hopper does not backup and overflow, which could contaminate the area. Camera technology can also provide visual status of connecting valves and hoses to ensure there are no leaks or excess vibration that can lead to costly repairs. Maintaining tight security to avoid theft is also a major concern due to the amount of expensive equipment and precious metals used at the site. These issues are driving the need for site surveillance, and the added video requirement has an impact on the choice of wireless technology. In order to support video on the network, IEEE 802.11n is being used to provide the additional bandwidth required by the many IP cameras. The cameras feed their data to a central NVR for archiving and playback in the data van, or video data can be streamed over the cellular network to a remote monitoring center. Security for the camera subsystems can also be accomplished through the use of a secure router to provide NAT and firewall protection. VPort 26A-1MP HD Camera NAT Port Translation WiFi to Datavan or Monitoring Site EDR-810 VPN/NAT/ Firewall AWK-3131 802.11n Radio Figure 7: Site and Process Surveillance using IEEE 802.11n and HD Camera solutions Operators are conscious of the security threat to industrial control systems and have concerns in that area. There is a tradeoff in how much security they are willing to apply due to the impact on performance and cost in many instances. In any case, certain steps must be taken to secure systems in accordance with industry best practices for the types of devices that are being used. First and foremost is creating a defense in depth strategy, which defends the network in many places so that a single compromise does not expose the entire network. In remote monitoring applications, access to external sites may be through an IPSEC encrypted tunnel. However, safeguards should be in place so that, for example, remote site ports that may be locally compromised do not allow access to the uplink. While the uplink is protected through encryption, the use of local area wireless technologies mandates that encryption such as WPA2 also be used to ensure that local wireless LANs are only used for the intended application. Doing so can prevent both unauthorized access as well as bandwidth overload, which could cause an application to stop. Firewalls, filtering, and deep packet inspection are being used to ensure that only allowed application traffic can cross network boundaries. In applications that use Modbus/TCP, deep packet inspection can be used to limit which Modbus 5
command sets can be sent to sensitive devices protected by the firewall. In addition to securing network services, shutting down or disabling unused ports is key to providing a secure operating environment and mitigating possible attacks. Moxa s EDR routers support VPN/NAT/Firewall and Modbus deep packet inspection and are being used in many different industrial applications to meet security needs. Security of the wireless infrastructure is also a concern for many customers. Moxa wireless devices support WPA2 encryption to ensure that data eavesdropping is not possible, and Moxa can also provide custom secure protocol support for your application upon request. Conclusion As the oil and gas industry expands in North America, there are more opportunities for building advanced monitoring and stimulation systems. Moxa can provide complete solutions to meet the needs of these applications. Industrial strength secure routers and gateways, redundant wireless radios, and extended temperature camera solutions are key components that can be used to build out a system. If you require expert knowledge or assistance in designing your system, Moxa is here to help. In addition, if you require integration assistance, our integration partners can help ensure a successful deployment. Product Reference EDR-810-VPN-2GSFP: Industrial secure router AWK-3121: Industrial IEEE 802.11a/b/g wireless AP/bridge/client AWK-3131: Industrial IEEE 802.11n wireless AP/bridge/client AWK-5222: Industrial IEEE 802.11a/b/g IP68 dual-radio wireless AP/bridge/client VPort 26A-1MP: IP66 day-and-night vandal-proof fixed dome HD IP camera for outdoors VPort 36-1MP: Rugged HD day-and-night box type H.264 IP camera MGate MB3170/MB3270: 1 and 2-port advanced serial-to-ethernet Modbus gateways For more information please visit www.moxa.com. Disclaimer This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor subject to any other warranties or conditions, whether expressed orally or implied by law, including implied warranties and conditions of merchantability, or fitness for a particular purpose. We specifically disclaim any liability with respect to this document and no contractual obligations are formed either directly or indirectly by this document. 6