Oil & Gas Middle East takes a fact-packed tour around the Ras Laffan site containing the largest and most complex gas-to-liquids plant in the world
You cannot accuse Shell of lacking ambition. CEO Peter Voser announced $100 billion of new investments in March, including a game-changing offshore floating LNG facility – and has completed a company-wide cost-cutting drive that will see the supermajor generate enough net cash flow at an oil price of only $60 a barrel to cover both its capital expenditure and the dividend.
It is in this context that the mammoth Pearl GTL facility in Ras Laffan Industrial City, Qatar, makes sense. After years of relative underperformance, Shell is looking to fundamentally transform and evolve it’s business.
It will take innovative, huge projects like Pearl to get them there. The company’s ambition is evident in every statistic available on the project. The project is expected to add nearly 8% to the company’s worldwide gas production, and is the principal source of growth for next year. The company reiterated its target to reach full production in 2012.
The field was first discovered in the early 1970s by what is now Shell, and Shell have made their reutn to Qatar in a big way, having repaired the poor relations with the government that presaged its exit in the 1990s.
Andy Brown, country manager for Qatar, told Oil & Gas Middle East that “LNG volumes have been diverted away from the US because of shale production. Pearl GTL gives Qatar very real access to a range of different markets and is a natural hedge for the State of Qatar against the vagaries of the gas market”.
The $19 billion development will produce 140,000 bpd of liquid fuels such as kerosene and base oil that are normally produced in a refinery, according to Shell, and 120,000 bpd of condensate and liquid petroleum gas at an average operational cost of just $6 per barrel.
The facility begins 60 km offshore, where two unmanned offshore jack-up rigs drill 30 meters into Qatar’s North Field, which at 900 trillion cubic feet is the largest in the world.
To put the size of the Pearl project in perspective: over its life time, the GTL facility will only use 7% of the North Field’s gas reserves. The gas is then transported onshore by two 30cm pipelines. The rigs were constructed in record times for Shell, under a new simultaneous operations system.
Once brought onshore, the gas is then sent to two processing trains. Train 1 is up and running and producing GTL products for export, train 2 will come onstream later this year.
The gas is then separated into pure methane and natural gas liquids, with the latter removed and exported.
In order to provide oxygen to produce syngas, Shell has built the largest oxygen production system ever built, comprising of eight vast air separation units, each the height of a ten-storey building. The air is cooled to within a fraction of absolute zero so oxygen can be separated from nitrogen and trace gases. 28,000 tonnes of 99.98% pure oxygen are produced per day.
The methane and oxygen are then brought together in gasifiers at 1,400 to 1,600 degrees Celsius to produce syngas. This process generates heat which is used for power generation at the plant – the whole operation at Pearl requires 180 megawatts of power a day, all of which is generated on-site.
At the heart of Pearl is Shell’s Middle Distillate Synthesis process, the result of decades of refinement of the Fisher Troph process pioneered in the 1920s. 24 1,200 tonne GTL reactors – twelve in each train – are loaded with 200 tonnes of a cobalt-based catalyst proprietary to Shell, said to be the most advanced type in the world.
Each reactor contains tens of thousands of feed tubes – that if placed end to end would stretch from Qatar to Japan, with just 150 grams of the rice-like catalyst having the same surface area as a football field.
Again, this process creates heat, which together with waste water is used for steam power generation at the plant.
The wax is then sent to a hydrocracker – the largest one ever built by Shell and one of the largest in the world – for Heavy Paraffin Conversion, where the long-molecule chain wax is split into GTL products under high heat and pressure.
All this runs on a continuous basis, thanks to the central control room. Operators utilise the largest process management system in the world to oversee the facility. The control room includes almost 1,000 circuitry control cabinets and 200 computer servers programmed with 12 million separate software codes.
The system is linked to every part of the plant by almost 6,000 kilometres of cables, which would stretch from Doha to London if laid end-to-end.
Once construction is complete the entire Pearl facility will run with only 800 staff at any one time.
Su-pearl-atives
1. At the peak phase of construction, Shell and their contractors were erecting enough steel to build two and a half Eiffel Towers a month.
2. Footprint of Pearl GTL is the same as London’s Hyde Park and Kensington Garden combined.
3. Shell’s combined upfront investment in Ras Laffan – both Pearl GTL and Qatargas4, is $20 billion.
4. 3,500 patents proprietary to Shell are at work at Pearl GTL.
5. Pearl’s 24 reactors weigh a combined 28,800 tonnes, more than 78 Airbus 380-800 airliners. Each is then loaded with 200 tonnes of catalyst.
6. Shell used enough concrete in the construction of Pearl GTL to build two Burj Khalifa’s, the tallest building in the world.
7. The total surface area of the catalysts in use at Pearl is equivalent to almost 18 times the area of Qatar.
8. Enough road journeys were completed in the construction of Pearl GTL to circumnavigate the globe 5,000 times
9. 77 million hours of construction at Pearl GTL went without a Lost Time Incident
10. Pearl GTL will take 1.6 billion cubic feet of natural gas to produce 260,000 barrels of oil equivalent when fully operational
Waste not want not
As well as GTL products and condensate, Pearl produces two things in abundance: waste water and sulphur. Water is in short supply in the Middle East, and there are 21 million tonnes of sulphur stored around the world, so for very different reasons Shell has been finding ways of reusing both.
The industrial process water produced when the syngas is passed through the catalyst is cleaned and then reused around the plant for cooling and as steam for power generation.
Shell’s industrial water processing plant at the Pearl site is the world’s largest for the recovering, treating and re-using of industrial process water, with a capacity of 300,000 barrels of water per day, necessary given Pearl is slated to produce at least as much water as hydrocarbon products.
“When fully operational the amount that Pearl GTL will produce makes it possible to run the plant without drawing on Qatar’s scarce natural fresh water resources or on seawater,” says Rob Overtoom, Technology Manager on the Pearl GTL project.
To deal with the sulphur Pearl produces, Shell has built one of the world’s largest sulphur processing plants, which when fully operational will handle 12,000 tonnes of the bright yellow chemical per day.
The sulphur not used for sulphuric acid manufacture has previously been stored, which has led to gluts and stockpiles of the substance in refinery facilities around the world.
Shell is now pushing more innovative uses for the substance, including as an additive to asphalt to improve durability. Additionally, the company has researched sulphur-based forms of asphalt and cement, with the latter not requiring any water, a key benefit in the Middle East.
At the end of the line
In addition to LNG, here is what Pearl GTL was built to produce:
GTL Base oils
GTL lubricants have preium characteristics, and Shell will significantly widen the availability of such with production from Pearl. The facility will produce enough synthetic oil each year to make lubricants for more than 225 million cars.
GTL Gasoil
Odourless Gasoil has superior environmental and performance characteristics to conventional diesel, and will be blended to provide performance products at the pump. Peral will produce enough to fill over 160,000 cars a day.
GTL Kerosene
Like GTL Gasoil, GTL Kerosene burns better, cleaner and less sulphurously than conventional jet fuel. Blends of GTL Jet Fuel of up to 50% have been approved for civil aviation by the American Society for Testing and Materials. Pearl is expected to sell one million tonnes per annum of GTL kerosene from 2012.
GTL Normal Paraffin
Pearl’s Parrafin has the advantage of not having to be produced next to a refinery, with savings on costs and the potential for locally-sited production if Shell rolls out GTL in other key gas markets, such as the US.
GTL Naptha
GTL feedstock is “much more paraffinic” than standard feedstock, says Andy Brown. “As a result,” adds Brown, “polyolefin yields are 10% higher”.
