In rugged, remote offshore environments, challenges abound. Equipment and employees must navigate unpredictable weather conditions while ensuring that production stays high, downtime remains low, and worker safety and security are protected—and none of these is negotiable.

Wireless communications networks help offshore operations traverse some of these challenges, providing a cost-effective way to monitor and control operations, both on the rig and remotely. Wireless network applications include the following:

• Internal communication on the rig
• Wireless connection of mobile applications
• Wellhead and gas-field monitoring and control
• Rig power management and monitoring
• Pipeline telemetry
• Data aggregation
• Process analytics.

Not all wireless networks are created equal, however, and the offshore oil & gas sector in particular presents some significant hurdles any network used must manage.

The challenges of wireless offshore

The most obvious challenge is that offshore operations are found in some of the most remote areas of the planet, which means that environments are harsh. Extreme temperatures, corrosive saltwater, constant vibration and pervasive dust and dirt are just some of the conditions in which wireless networks need to be deployed and run.

Reliable, constant connectivity is another major concern. While an offshore network’s capabilities must go beyond enterprise reliability, even some industrial-grade wireless networks are not suited to an offshore operation, where all assets are constantly in motion.

Offshore oil & gas operations consist of both fixed rigs and moving equipment, which includes maintenance tugs, work vessels and floatels. All parts of the operation must have connectivity and share data, but the mobile equipment may not always be able to "see" a network antenna on a rig from all positions—called "line-of-sight." In areas with rough seas, a boat or floatel may not have line-of-sight to an antenna on a rig. In this event, connectivity will be lost.

In addition to environmental and line-of-sight concerns, the installation itself can be an issue. In the production field on a drilling rig, OSHA considers many areas hazardous because of the possibility of explosions. This limits where, when and how networks are installed. The installation or redeployment of a network requires shutdown for safety reasons-and a shutdown may mean several million dollars in lost production.

Not to be forgotten is the need for unassailable network security. The U.S. Department of Homeland Security identified the energy industry as one of 16 industrial sectors "so vital that their incapacitation or destruction would have a debilitating effect on security, national economic security, national public health or safety, or any combination thereof."

In 2015, there were 16 recorded cyberattacks on energy installations considered serious enough for the Industrial Control Systems Cyber Emergency Response Team (ICS-CERT) to investigate. Thus a wireless network must be more than just reliable and rugged: it must stand up to cyberthreats and protect critical data, especially as cyberattacks on offshore rigs are increasing. Unfortunately, many wireless networks can’t overcome these challenges. 

Historical limitations

In the past, satellites provided offshore producers with high-latency, low-bandwidth communications that were useful for transmitting telemetry data, but were not appropriate for automation and control systems requiring less latency, or for fixed and mobile multi-services like voice and video requiring more bandwidth. Many industrial-grade wireless network technologies can provide low-latency and high-bandwidth, but have other limitations.

Point-to-point (PtP) systems are unable to deal with changes on the Z-axis—such as the vertical movement of boats and floatels in rough seas. A PtP network would require a wide-scale antenna system because at least one side of the network will always be moving. These systems also have only a single signal going back and forth, which creates the possibility of interruptions.

Point-to-multipoint (PtMP) systems need full coverage on one or more vessels, which requires additional equipment. Still, only one signal is going to and from each point.

More hardened offshore communications equipment is focused in expensive license bands such as 6 GHz or 10 GHz ranges, which means spending tens of thousands of dollars on links from one point to another with no additional backup communications—and even then, the bands aren’t built for offshore. Offshore operators can add capabilities so that the PtP/PtMP system can track assets to maintain communications, which works while equipment is moving side-to-side or back-and-forth, but not up-and-down in rough seas—and the signal will not travel through water, or through a wave.

Cellular LTE technologies have similar limitations; their frequencies don’t work well in ocean environments. These technologies are multiple-input, multiple-output (MIMO), meaning multiple antennas are used at both the source (transmitter) and destination (receiver). When signals are transmitted, each wave on the ocean causes a new multipath and angle, like ripples on a pond, and is constantly changing. Antennas receive all signals out of order, and because so many multipaths are coming into a radio, throughput is nonexistent.

Offshore operators now have more options in a wireless network, however. 

What to look for

There are a few key characteristics of an offshore-ready network.

1. A network must have high availability. Oil & gas operations strive to have the highest availability in communications, whether onshore or offshore, but the conditions in which they operate cripple many networks. Environmental or accidental radio-frequency (RF) noise, broken RF equipment, dynamic changes in the characterization of the RF site, and the range on non-compatible RF devices all can interfere with wireless-network performance.

Any single-path or PtMP network has a single-point-of-failure and that reduces reliability. A network should allow for and survive any changes to network infrastructure, whether planned or unplanned, by having multiple radios creating multiple paths, and thus no single-point-of-failure. Even if a radio on one piece of equipment or vessel fails, the network should be able to reroute, limiting connectivity problems to an individual vessel versus multiple vessels, and ensuring that operations are minimally affected.

Even on rough seas, a network should have enough peers that workboats tossing on the waves can still connect to it; a workboat may not be able to "see" the main antenna tower through the waves, but can see a peer workboat and connect via that boat’s radio, maintaining connectivity.

2. A network must be highly secure. Because of cyberthreats to the energy sector, an airtight network is an absolute must-have.

Networks with military-grade security with configurable per-hop, per-packet authentication are ideal for the offshore oil & gas sector. A network should offer end-to-end encryption-meaning when encrypted information flows through the network and comes out another radio it stays encrypted until it is delivered to its destination, ensuring privacy.

A network must allow real-time data to enhance production and safety. A high-bandwidth, low-latency network allows critical information to be vetted and processed in real time. Equipment can be fitted with sensors that send data continuously to a central collection point via the network, allowing operators to see patterns and prevent problems.

Semi-autonomous or autonomous equipment can be controlled remotely via the wireless radios appended to sensors, meaning power can be killed before or at the time of an issue without waiting for a workboat to reach the equipment and an operator to turn off a valve or pump. Remote data-gathering also can lower operating costs and increase safety; employees can perform duties from onshore sites and collaborate with a few platform workers via camera. Fewer platform workers mean less transport to and from the platform, minimizing transportation costs and reducing risk.

Data like engine run-time allow for proactive maintenance, and can help engineers catch problems with equipment and change their processes, saving money on repairs or replacements and reducing downtime.

On the safety and compliance side, proper environmental sensor packages can show gas leaks that technicians cannot smell, and control equipment can keep technicians in a safe zone if there is an issue. Sensors can detect leaks or changes in pressure and shut off a pipeline automatically.

Some offshore vessels are stationed in zones where piracy is a concern, and surveillance footage streamed over a strong network can keep infrastructure, people and assets more secure. Equipment and vessels also can be outfitted with GPS tracking devices to prevent or detect theft or piracy.

3. A network must be scalable and reconfigurable. Offshore, drilling, cabling and tug vessels are always coming and going, and bobbing up and down. Standard design and equipment cannot support the nomadic state of an offshore oilfield.

A network should have assets that allow operators to reconfigure and move radios and network infrastructure as the environment changes. For example, there may be multiple vessels onsite during drilling, but support vessels leave when drilling ends, while others are permanent. With PtP or PtMP networks, operators need to completely redesign the network for the remaining vessels to scale it down each time new vessels leave, and then do it all over again the next time drilling commences and new vessels or equipment arrive.

A scalable, re-deployable network makes it easy to move vessels on and offline, expanding and contracting the network as needed for each rig, while the network continues to operate with the same reliability. Shutdown is limited to the initial installation, saving on the costs associated with downtime. 

The power of the right network

In the offshore oil and gas sector, environmental conditions are a constant challenge, and people and equipment are always in motion, so access to real-time data powered by a strong communications network is a necessity.

The right network will allow offshore operators to boost productivity and even cut costs by allowing proactive maintenance and reducing downtime. In the current era of low oil prices, an offshore operation can take advantage of the efficiencies a powerful network can create, while keeping workers safe and ensuring critical industry data stays secure.

Josh Parker is ‎director of customer support and product management at Rajant Corp., a private wireless network provider and mobile networking pioneer. He can be reached at jparker@rajant.com.

For more information:

www.dhs.gov/critical-infrastructure-sectors 

https://ics-cert.us-cert.gov/sites/default/files/Monitors/ICS-CERT_Monitor_Nov-Dec2015_S508C.pdf 

Original content can be found at Oil and Gas Engineering.

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