Autonomous underwater robots used for deep-sea drilling operations

Many of the world's oil and natural gas resource lie beneath the oceans. Autonomous robots can help explore and dig them out.

By Tanya M. Anandan March 9, 2021

Many of the Earth’s oil and gas resources lie beneath its oceans. Although drilling operations are down dramatically due to lower demand and lower oil prices, worldwide surpluses, and now the effects of the pandemic and other uncertainties, of the 1,000-plus active oil rigs around the world, nearly 200 of the active rigs are offshore.

Oil and natural gas drilling rigs can operate in water depths of two miles. Many of these deepwater wells and pipeline systems have come to rely on unmanned underwater vehicles to help perform installations, inspections and repair and maintenance. But these unmanned vehicles typically need to be transported to the offshore site, which can be 100 or more miles out to sea, and then remotely operated from there, often via tether. This common scenario requires a manned vessel topside.

In 2014, a group of NASA roboticists set out to change that paradigm. Houston Mechatronics (HMI) was born. They designed a combination autonomous underwater vehicle (AUV) and remotely operated vehicle (ROV) with the ability to switch back and forth between the two functional forms.

“We believe subsea operations are inefficient because of the reliance on large surface platforms like a boat,” said Sean Halpin, HMI’s senior vice president of products and services. “If we can remove the boat from the operation, we are removing an enormous cost. That’s the disruption here. We are confident we can accomplish inspection, maintenance and repair (IMR) for about half the cost of what everybody is doing today.”

Underwater transformer

Aquanaut is an all-electric subsea robot that transforms from a long-range AUV to an untethered ROV with two robust arms. In AUV mode, with the arms enclosed within its hydrodynamic hull, the underwater bot can cover over 50 nautical miles in one mission thanks to an onboard lithium-ion battery and thrusters for propulsion. Along its journey, Aquanaut’s onboard high-precision geophysical instruments allow it to survey the seabed and collect data.

Once the robot reaches its destination, it transforms into ROV mode. The top half of the hull raises and the head swivels into place to expose stereo cameras and powerful 3D sensors. Additional thrusters emerge to provide better maneuverability. Two 8-axis arms unfold with built-in force sensors and grippers, ready for work. Manipulation tasks could include waterjet cleaning, inspection of cathodic protection (a common corrosion mitigation method for submerged metal structures), flooded member detection (FMD), and other tasks to assess the condition of oil and gas assets on the seafloor.

Communication is facilitated via an onboard acoustic modem. A small unmanned surface vessel relays signals between the robot and communication satellites, allowing the robot to be controlled from anywhere in the world. Although challenging, this communications scenario is familiar to Aquanaut’s creators from their days at NASA developing sophisticated robots for operation in remote locations, like space.

HMI was founded by Nicolaus Radford and Reg Berka, both NASA alums. CEO Radford led research in humanoid robotics, including Valkyrie and Robonaut, for the International Space Station and future Mars missions.

The company’s investors are betting on not only the transformational nature of Aquanaut’s form factor, but also the transformation HMI’s technology and services will bring to the energy sector as a whole. With oilfield services giant Schlumberger and drilling firm Transocean on board, HMI has raised $26 million over two investor rounds and expects to close a Series C investment within the next two quarters.

Subsea service for offshore asset inspection

HMI is targeting two main markets: 1) Energy, which includes oil and gas and a growing renewables sector, and 2) Defense. Right now, they’re working with the U.S. Department of Defense (DoD), but HMI expects international interest in applications such as port security down the road. Aquanaut could stealthily patrol offshore waters without detection from the surface. HMI also sees potential in the telecomm market, inspecting and maintaining long transmission lines under our waterways.

Customers, like an oil company, can either contract directly with HMI, in which case HMI will deploy Aquanaut and perform the work themselves, remotely operating Aquanaut and directly interacting with the customer. Another option is to partner with an established service provider in the oil and gas industry. In that case, HMI will deliver Aquanaut and make sure it’s operational, but the other service provider will provide direction to HMI and have responsibility for all customer interaction.

In the future, fleets of Aquanaut robots will accomplish economies of scale. Take an Uber analogy. A company orders an Aquanaut and it reports for work when needed from its seabed-based AUV charging station, part of an emerging idea for mobile subsea residency. Current ROVs must be delivered from point A to point B as needed and require a team of operators stationed on a surface vessel. With HMI’s technology, one fleet operator, an HMI team member stationed onshore, will be able to supervise and control multiple robots.

Shared control vs. autonomy

HMI principals feel a high level of control is the most efficient way to deploy Aquanaut in the energy sector, where they can make sure the technology is operated safely and effectively. This is especially true in the risk-averse offshore oil and gas industry, where the idea of full robotic autonomy will need to marinade further. HMI uses the term “shared control” to refer to the semi-autonomous, remote operation of Aquanaut.

“In the oil and gas market, the robot only makes decisions on how to do something efficiently,” Halpin said. “If we say go touch this, it will arrange its joints appropriately. We give it that freedom, and we set a boundary for that action.”

Aquanaut is capable of far more autonomy, but Halpin said this market is not ready for that. “They want check-ins with a human operator a lot more frequently than you would see in the defense market, where they really like a high degree of autonomy.”

So why the massive arms on Aquanaut? HMI anticipated the types of manipulation tasks it would need to do in these environments, such as handling tools and turning valves, but it will be a while until the industry is ready to relinquish that kind of control.

“A conventional ROV looks like a small fridge with two little T-Rex arms on it,” Halpin said. “So you have to move the vehicle a lot. Aquanaut provides 40% more manipulation workspace than a conventional ROV.”

If the vehicle is in a position where the arms are unable to properly perform a task, the vehicle will reposition on its own. There’s one control system for the entire robot.

“It’s all about efficiency. We don’t want to take three hours to pick up a tool.”

Maybe someday Aquanaut will go it alone. But only after it earns the energy sector’s trust. In the meantime, the underwater transformer will keep its human operators safely onshore as we learn what it can do on the seafloor.

Tanya M. Anandan is contributing editor for the Robotic Industries Association (RIA) and Robotics Online. RIA is a not-for-profit trade association dedicated to improving the regional, national, and global competitiveness of the North American manufacturing and service sectors through robotics and related automation. This article originally appeared on the RIA website. The RIA is a part of the Association for Advancing Automation (A3), a CFE Media content partner.

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Author Bio: Contributing editor, Association for Advancing Automation (A3).