Old ships and oil rigs can help revive the oceans

The know-how is hiding in plain sight if you know where to look.

Share on linkedin
Share on facebook
Share on twitter

With all the ink spilled over oil company skirmishes with activist shareholders, you might have missed or already have forgotten some pertinent words from Shell’s CEO Ben van Beurden.   

“Companies like us are absolutely needed for the solutions that the world needs,” van Beurden declared in a recent interview with HBO

Needless to say, this potential – van Beurden feels – is widely unacknowledged and unappreciated. 

There was more. “If you believe that the energy transition is going to be solved by start-ups or companies that have yet to be invented, then I would say: dream on.”

If we don’t save the ocean, we won’t save the planet. And the petroleum industry has an integral role to play. 

Shell’s CEO didn’t explain it, but the offshore oil and gas industry has already provided a substantial knowledge base about how to regenerate marine ecosystems.

It also has the engineering expertise needed for offshore wind and the future development of the holy grail of regenerative renewable energy, ocean thermal energy conversion (OTEC).

This, in turn, has a knock-on effect for low-grade geothermal energy development, which also has a key role to play in decarbonization.

Rigs can become reefs

In the 1970s, marine scientists began documenting massive growth of marine life on oil and gas rigs offshore California and the US Gulf of Mexico. 

Shellfish were growing on limestone that had accumulated on the rigs as a result of the cathodic protection systems – already a decades-old technology by then – that were being used to control corrosion. 

The discovery of so much marine life on offshore rigs led to the US adopting a rigs-to-reefs program. Since 1987, about 11% of decommissioned rigs in the Gulf of Mexico have been left in the water as reefs, totaling 558 conversions as of 2020.   

Offshore petroleum production facilities started out simply as petroleum production facilities, but some have evolved into de facto micro marine-protected areas. The decommissioned structures support ecotourism such as diving and fishing as well as regional fisheries.

In terms of marine ecosystem preservation and development, the rigs-to-reefs program is proving to be a killer app. 

There are only 27 rigs in offshore California waters, but these already support more biodiversity than the marine-protected areas in the same area.  

After more than 30 years of effort in the Gulf of Mexico and more than 50 years in California, the science is unambiguous: marine life is attracted to artificial structures in the sea.  

This marine life can be encouraged as a global public good, or it can be killed off by removing decommissioned rigs.

Relevant Sustainable Development Goals

After the discoveries in the Gulf of Mexico in the 1970s, cathodic protection systems were adapted for standalone reef cultivation at various sites around the world. Two of the largest such reefs have been alive and well in Indonesia since 2007.

Today, we know we can grow reefs faster than we are killing them off, largely because of the knowledge base from California and the Gulf of Mexico.  

We also know that rigs-to-reefs programs are replicable – if governments want them (and some allegedly well-informed governments don’t).

However, not all rigs are suitable for conversion.  The conversion rate in the US has been around 11%, although that figure might be much higher in Southeast Asia. 

Based on the US conversion rates, there are at least 150-200 rigs-to-reefs candidates in Asia and the Pacific, mostly in Indonesia, Thailand, Malaysia and Vietnam.

Existing rigs which are host to mature reefs are micro marine-protected areas. Taking these rigs out of the water would constitute an environmental crime.


Massive potential for offshore wind
What else can the petroleum industry offer that no one else has? 
Offshore wind represents another under-developed asset class.

The offshore wind industry was born in Europe, enabled by more than 25 years of offshore petroleum operational know-how in the North Sea. Without this engineering knowledge base, offshore wind installations would never have survived for 20 to 30 years.   

The International Energy Agency (IEA) estimates that offshore wind could deliver more than 400,000 terawatt-hours per year worldwide. That’s far higher than current levels of global energy production (electricity and other energy production), which was about 175,000 terawatt-hours in 2019.

Offshore wind is integral to the global energy transition.   

What’s more, a lot of future offshore wind will come from floating installations in deep waters, relying on know-how derived directly from the offshore oil and gas industry.   

At the same time, if we want to save the oceans, offshore wind installations need to encourage marine growth, applying lessons learned from the Gulf of Mexico.

This also provides opportunities for by-product revenue from marine aquaculture and ecotourism. 

Marine aquaculture is vital if we want to feed 9 billion people without destroying the planet. Floating seaweed and shellfish farms, co-located with cultivated reefs – which we know how to grow from converted oil and gas rigs – are part of the solution.  

Another killer app, ocean thermal energy technology or OTEC, can integrate these marine biodiversity farms into offshore renewable energy development.

As the holy grail of regenerative renewable energy, OTEC operates 24/7/365. The cold water pumped up for energy conversion is nutrient-rich, so it can support “no-feed” marine aquaculture. OTEC systems can also be designed to produce fresh water.

OTEC only works in deep water, typically 1,000 meters deep. If we want to scale it up, we need to deploy OTEC on floaters. Again, the know-how for these floating systems – which have already been adapted for floating wind – comes from offshore oil and gas.


A second life for aging ships
OTEC can also help meet International Maritime Organization (IMO) regulations to halve greenhouse gas emissions from maritime shipping by 2050.

The future of OTEC is on floating installations, and it is technically possible to convert 20-year old ships for OTEC duty.  These aging ships can also host marine aquaculture and reef cultivation, as well as some solar panels and smallish wind turbines.

Retiring a typical ‘Panamax’ ship  a medium-sized vessel able to travel through the Panama Canal  10 years early will avoid fuel emissions with a net reduction of about 0.5 million tons of carbon dioxide.

While the potential for rigs-to-reefs is maybe 200-300 rigs worldwide, the potential for wrecks-to-reefs is far higher, with at least 10,000 candidates. Converting 20-year-old freighters would be a good place to start.

Accelerated retirement of 10,000 Panamax class ships would avoid 5 billion tons of greenhouse gas while helping to grow natural capital in the oceans. Not enough to save the planet but a lot more than the Paris climate accords have achieved.

Expanding OTEC also opens another opportunity.

OTEC uses a commercially proven solution for low-grade geothermal energy, called organic Rankine cycle (ORC) generation technology.

Globally, there are tens of thousands of oil and gas wells with associated water that is typically too salty for agricultural, industrial or municipal use but within the right temperature range (90-110C) for ORC heat-to-power operations.

Scaling up OTEC can foster low-grade geothermal growth, and vice versa, creating a virtuous cycle.

ORC generation units can also be used for heat-to-power applications in heavy industries, especially hard-to-decarbonize industries like cement, iron and steel production.

Remember those cathodic protection systems that can be used to grow limestone?  With a bit of focus research, those can also help recover minerals from oil and gas field production water, helping solve one of the biggest environmental problems for the upstream oil and gas industry.

Show me the money

Shell CEO Ben van Beurden also talked about the scale of investment required to save the planet  about 3-5% of GDP (or ~US$2-3 trillion) per year.

This scale of investment will come mainly from the private sector, enabled by government policy decisions.

The same governments that have spent trillions of dollars on Covid-19 response would be well-advised to implement the policies necessary to encourage Shell and its peers to start making the trillions of dollars per year required to save the planet. (Hint: don’t waste time and money traveling to COP26.)

Solutions such as offshore wind, OTEC and low-grade geothermal do not require any new technology. What they need is know-how from the oil and gas industry, as well as brute force investment of trillions of dollars per year for the next 10 years.

That, in part, will come from the corporate transformation of traditional petroleum companies. It is critical that governments open the door to let this happen.

Share this article

Share on linkedin
Share on facebook
Share on twitter

Dan Millison

Manager, Transcendergy LLC

Recommended Reads

Welcome to the Tech For Impact community

Let's get acquainted

What is your name?

email list sign up form

You may unsubscribe at any time using the link in our newsletter.

Check your inbox regularly for a newsletter keeping you up to date with the stories, ideas and good news that your community is talking about.