Flaring: Equivalent to taking 77 million cars off the road?

Photo: Total

The Moho Nord oil exploration and production project offshore Angola is a large-scale deepwater development. It's the biggest project to date carried out in the Republic of the Congo. Moho Nord also exemplifies Total's determination to end routine flaring, a source of greenhouse gas emissions. It's a bona fide technological challenge that addresses environmental, industrial and societal concerns without compromising safety standards. Yves Duteil, a naval architect by training and Moho Nord project director, sketches the broad outlines.

Producing an oil field is bit like working on a giant bottle of soda. The product starts out under high pressure, but stabilizes after you open it. Plus, you must take steps to get it all out. The pressure is caused by gas in the oil and absolutely must be dealt with, for safety, environmental and technical reasons. Because that gas is around for as long as a field is in production, flares are installed at all oil sites. Their main purpose is to ensure safety by burning off the associated gas so that it doesn't build up in installations, which could create hazardous overpressure.

All told, Moho Nord produces 140,000 barrels of oil per day, in water depths ranging from 750 to 1,200 meters.

77 million cars

But this so-called routine flaring has an environmental impact. Globally, it generates an estimated 350 million tons a year of greenhouse gas emissions. Since 2015, the World Bank, via Anita Marangoly George, former senior director of Global Practice on Energy and Extractive Industries, has pushed to eliminate "a huge amount of greenhouse gas, equivalent to the emissions of 77 million cars," by 2030.

Total, which joined the initiative in its very early days, was the first company to do so. The group is also one of the GGFR1 partners to receive an award for its efforts, in September 2015, when its Nigerian affiliate was recognized for achieving flare-out on the Ofon offshore field. The move cut the amount of gas flared in Total's exploration and production operations by 10 percent2. This makes Total, which also continues to optimize the energy efficiency of all the company's installations, one of the majors the World Bank can count on to achieve its goals.

New projects dispense with routine flaring going forward

Brought on stream in March 2017 off the shore of the Republic of the Congo, Moho Nord is one of Total's most recent oil exploration and production projects. It's also one that was designed from the outset not to flare gas under normal operating conditions. It's a major investment, planned to last 30 years, making it the biggest oil project ever undertaken in the country. Yves Duteil served as project director. He points out that: "Total has set ambitious goals for reducing its greenhouse gas emissions, notably by ending continuous flaring and using the associated gas locally. Between 2005 and 2015, we halved the volume of gas flared at our operated facilities3, excluding the initial start-up phase, from 15 million cubic meters per day to 7.2 million. We want to do even better and have pledged to cut routine flaring by 80 percent between 2010 and 2020 and completely eliminate it by 2030."

That determination and those goals pose many challenges. "Flaring is first and foremost a safety issue," says the project director, "and on an 80-worker rig that processes 100,000 barrels a day, we cannot compromise on safety." An oil field never stops being a hazardous site, one that handles a high-pressure product composed of oil, water and flammable gases such as methane, ethane, propane and butane. Some, like methane, come with the additional downside of having a greenhouse effect 23 times greater than carbon dioxide's.

So flares quickly remove any gas that builds up anywhere in the oil processing facility. The flare on the FPU4 Likouf no longer burns continuously. It is switched on from time to time instead. "We made this a requirement from day one of the project," explains Yves Duteil. "We applied what we learned from the Pazflor and CLOV projects in Angola, whose FPSOs5 have been operating since the early 2010s, giving us substantial experience of routine flaring reduction. This expertise enabled us deploy an ultra-reliable, tested, verified system6, including very strict availability requirements, on the Likouf. It is vital that flares switch on and start burning if needed, while extinguishing and shutting off just as quickly. We must balance environmental protection and safety, without compromising on either."

Maximizing upsides

Although ending routine flaring is a big step forward, the Moho Nord project strove to develop other positive environmental impacts.

One route it took was to work on the FPU's energy efficiency. Waste heat recovery systems were installed on the exhausts of the three Rolls-Royce turbines that power the all-electric Likouf. They produce enough electricity for a city of around 80,000 people7. This sidesteps the need for additional boilers, to heat water for example. Another was opting to reinject produced water into the reservoirs to maintain pressure, through a closed circuit and without discharges into the ocean.

The Moho Nord oil project is also an opportunity to help create value in the host country. Total builds local economic capacity "while being careful to ensure that the activities we support or develop with local businesses are sustainable, that is, that they continue after Moho ends," says Yves Duteil. The company also trains local managers and operators in subsea production, to make them part of operations. And it transfers skills to Congolese professors, so that they can develop technologies compatible with the project in their universities or engineering schools.

That's what the Betosala program, which means "let's work together" in the Kituba language, is all about. "We must support Congolese entrepreneurs long term, prior to and during Moho Nord's production, to help them better prepare their future. In a country that relies on oil for more than 70 percent of its GDP8 (gross domestic product), diversifying the economy is a critical issue," concludes Yves Duteil.

What will deepwater projects look like in the future?

Outside of the flaring issue, the industry may continue working to make its "floating plants" more energy efficient. According to Moho Nord's project director, "We'll certainly be able to lower turbine consumption. We must keep our eyes open for technologies that might be more efficient than the ones we use now."

However, one day floating facilities may very well no longer be needed. A few decades from now, all the equipment needed to process oil may be installed on the seabed. No more need to flare gas, which would stay put, with pressure and temperature conditions unchanged. "The deep offshore industry is starting to move to the ocean floor. We'll also be able to run future subsea installations from land. All for less than the cost of building a hull and onboard equipment."

It's a future that will require more research and more developments and innovations. Its implementation and profitability remain strongly dependent on oil prices.

1 Global Gas Flaring Reduction Partnership.

2 In 2016, Total's direct greenhouse gas emissions amounted to 39 MtCO2-eq in its operated scope, down 23% from 2010. Of that total, 48% was from the Exploration & Production segment and 51% from the Refining & Chemicals segment. The Marketing & Services segment accounted for around 1%. […]. Source: Total, Integrating Climate Into Our Strategy, May 2017.

3 The activities, sites and assets operated by Total S.A. or a company it controls, i.e. those that Total or a Total-controlled company operates or is contractually responsible for managing operations: 808 sites at December 31, 2016. Source: Total, Integrating Climate Into Our Strategy, May 2017.

4 Floating Production Unit, a vessel used to process the oil extracted.

5 Floating Production Storage and Offloading unit, a vessel without a propulsion system, used to process and store oil and gas produced offshore.

6 Also called HIPPS, for High Integrity Pressure Protection System.

7 The average French household uses around 5,000 kW of power a year.

8 Source: World Bank.

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