A subsea adventure

Without remotely operated vehicles, there would be no deep-water oil and gas industry.

The depths of the ocean have always fascinated adventurers and explorers. Including those that took on a career in the oil and gas industry. Offshore exploration started in 1897 when a derrick was set up on a wharf sticking out from the Californian coast. Over time, seagoing rigs ventured further offshore and, as they did, the water got deeper and rig designs evolved. Then, in 1961, Shell completed the first subsea well, in the US part of the Gulf of Mexico, and the industry turned its gaze in a new direction.

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In a subsea completion, production equipment such as the wellhead is installed on the seafloor instead of on the topsides of a platform. Subsea technology helps companies exploit fields that aren’t big enough to justify investing in a whole platform, for instance. Sometimes, using dry Christmas trees (wellheads that are out of the water, on a platform) isn’t viable and a subsea completion (with a wet tree) is the only option. Relocating equipment to the seafloor also reduces load, so smaller, lighter and less costly floating structures can be used. In addition, once on the seabed, the kit is protected from wind and waves, and isn’t exposed to the platform’s potentially hazardous movement.

To date, the oil and gas industry has completed thousands of subsea wells. And subsea engineering has significant potential for growth. As the technology advances, more production-related activities are being moved to the seafloor, with a range of economic and safety-related benefits, says Per-Arne Nilsen, head of Total’s subsea technology department. “We believe subsea technology will be a key for successful development in the future,” he says. “And, by having production equipment subsea, we potentially create a safer working environment.” Eventually, it should be possible to relocate all production equipment to the seabed, he adds, creating a fully autonomous subsea plant – a goal Total hopes it might accomplish within 10-15 years.

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A unique environment

But imagine trying to install industrial-scale equipment on the seafloor, move objects or dig trenches – all under 10,000 feet (3,000 metres) of pitch-dark water and 4,500 pounds per square inch (310 bar) of external pressure. “It’s an environment few will ever experience,” says Mike Dupré, a senior subsea engineer at Shell. “You need a sense of adventure.”
Subsea engineers can’t actually visit the environment they’re designing kit for, of course. Installing, monitoring and maintaining systems deep below the surface of the ocean is done by intermediaries called remotely operated vehicle (ROVs), thruster-powered underwater robots operated by pilots at the surface with joysticks and computer screens.

ROVs started being widely used in the early 1990s, when exploration was regularly taking place in waters that were too deep for divers – about 1,000 feet. At first, the technology could only cope with simple tasks, like taking photographs or doing basic manipulations. But ROVs quickly became more physically capable; equipped with serious horsepower, today’s machines can accomplish things that were once unthinkable. In fact, without them, there would be no deep-water industry at all.

Ranging in size from a small suitcase to a large van, ROVs are kitted out with a range of tools, from cameras for filming subsea environments to versatile robotic arms for grabbing, moving, cutting and digging. Some are autonomous, battery-powered vehicles, but most are tethered – connected to offshore platforms via an umbilical link housing communications and power cables.

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Even safer

The technology they’re equipped with continues to develop apace, unlocking new possibilities in offshore E&P. At present, says Dupré, there is a strong focus on leveraging the potential of ROVs to make the offshore environment as safe as it can be. Originally, the idea behind ROVs was to do jobs divers could no longer perform because of water depth; now technological refinements are helping them take over any number of hazardous oilfield tasks – in all offshore environments, not just deep water. Advances in communications technologies, for instance, are making it possible to operate exploration or production equipment without anyone actually being on a platform. This could have important financial benefits as well as safety ones; during a hurricane or storm, for example – which regularly disrupt production from the platforms dotted across the Gulf of Mexico – oilfield personnel could be relocated to the shore, making it feasible to continue producing from subsea projects whatever the weather. The equipment itself, meanwhile, would be fine, since a storm ripping across the surface has little or no impact on the seabed.

Artificial intelligence (AI) technologies could transform the business too by, for example, unlocking resources in environments that were previously too hostile for oil and gas operations. In the Arctic, where seas freeze over for months at a time, offshore operations rely not just on ROVs, but on their ability to be self-sustaining while isolated below the ice. That will require self-navigation, and collision-avoidance, decision-making, self-diagnosing and self-repairing capabilities. Equipment that can fix itself or even anticipate and avert problems could radically improve safety in other areas of the business, and reduce costly downtime.


A long way out

Mike Dupré has been involved in numerous major subsea projects for Shell, including the record-breaking Perdido development, 200 miles off the US Gulf coast.

“We spend four to five years designing and planning a job and then up to a year offshore constructing. My job is in the office right now because we’re in a design phase. Then I’ll transition to an offshore installation vessel for extended periods during the actual execution of the work. I get to work in both environments, but there’s plenty of flexibility and some specialists choose one or the other.

“You’re usually based somewhere with a high concentration of oilfield technology sources, like Houston or Aberdeen, but your project could be anywhere and your equipment could be sourced from anywhere, so you have to travel quite a bit. “We get to see the full spectrum of activity, from initial design to operation. Time in the office is more creative because you have lots of resources around you – really smart folks to draw ideas from and bounce ideas off. But the time offshore is more rewarding, because you actually see the thing you designed getting built and installed on the seafloor.

“The experience of being offshore varies. You could be on a large heavy-lift vessel with 300 people living on board, like a small city, or on a small boat with a much more maritime feel. You could be close to shore, in sight of vessels and other platforms. Or you could be 200 miles offshore, where a lot of deep-water activity is taking place now in the Gulf of Mexico. When there are no lights anywhere on the horizon … that really feels a long way out.”

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Blue-sea thinking: subsea-to-customer

Per-Arne Nilsen, head of Total’s subsea technology department, has been involved in the subsea industry for nearly four decades.

Offshore developers should one day be able to place all of their production, processing and storage equipment on the seabed – effectively making costly offshore platforms unnecessary, says Total’s Per-Arne Nilsen.

In subsea projects, production-related functions are placed on the seafloor instead of on a platform and, as technology advances, the number of jobs that can be done in this way is increasing. Total’s Pazflor project, for example (offshore Angola), was the first high-capacity, high-quality subsea system that could separate gas and liquids as they emerged from subsea wellheads – with numerous safety-related, technical and economic benefits.

For now, though, subsea wells still need to be connected to elaborate and costly host facilities. These receive, process and store produced fluids before they can be offloaded to oil tankers for onward transportation to markets – or exported via oil or gas pipelines. Eventually, however, even tasks like oil storage might be performed on the seabed, says Nilsen. “The ultimate vision is subsea-to-customer. You would effectively load produced fluids directly to tankers from subsea facilities, which would avoid the need for the kinds of facilities we’re building today.” Subsea-to-consumer may be a realistic option for future gas developments too, he says.

A more immediate concern, he adds, is ensuring subsea projects remain economic over the next few years – which means keeping rapidly rising costs under control, and boosting efficiency and productivity. In such a challenging operating environment, this will rely heavily on the creative use of technology – from game-changing scientific breakthroughs to the innovative adaptation of technologies from other industries, such as telecommunications and aerospace.

But, in the subsea sector, technology and business have always been two sides of the same coin – presenting engineers with numerous compelling career pathways. “The subsea industry is very transverse,” says Nilsen. “It offers significant challenges to people interested in technology and technical development. And it needs business-minded people who understand how everything fits together. There’s so much you can do.


 

This isn’t a game

For now, the AI vision remains partly in the realm of science fiction. Yet it could easily become a reality. ROV manufacturers have a remarkable track record of absorbing and adapting advances in other fields for use in the hostile deep-water environment. The gaming industry, for instance, has catalyzed the use of simulations, which give ROV pilots the invaluable chance to practise tricky manoeuvres before attempting the real thing. The advent of fibre optics, meanwhile, means more data can be streamed to the surface than before. Advances in the power industry have been adapted to the subsea environment, extending ROVs’ physical capabilities. Drone technology, meanwhile, has plenty in common with autonomous ROVs.

“Twenty years ago, we didn’t even think of trying to develop things in 10,000 feet of water,” says Dupré. “Five years ago, we weren’t thinking about how to configure a seafloor system to produce fluids at a temperature of 400°F. I don’t know what the challenges are going to be in 10 years, but I do know that finding and producing oil is getting harder and more technology-dependent. If you like challenges and doing unique things with a lot of creativity, then subsea engineering is a great choice.”

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