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Upside down smokestacks


Okay, I’m back form my trip to Finland and the UK. I’ll post more thoughts and observations from the trip over the coming days. There’s a lot to talk about.
In the meantime, I wanted to draw readers’ attention to a very interesting article in today’s National Post newspaper about a highly effective carbon sequestration system that’s up and running on a huge scale near Weyburn, Saskatchewan. I didn’t realize such potential to offset global warming existed anywhere, never mind Canada. To wet your appetite for the article (which I’ve pasted below), let me just quote the following:
“Geologists say Canada is blessed with huge sedimentary basins that have the potential to hold mind-boggling volumes of the gas.
“We’d run out of fossil fuels before we’d run out of storage space,” says geologist Malcolm Wilson of the University of Regina.
On a global scale, scientists estimate there is room to bury the entire world’s CO2 emissions for hundreds of years.”
Now, here’s the article:


Oil reaped from farm of ‘upside down smokestacks’
Carbon dioxide buried

Margaret Munro
CanWest News Service
Wednesday, May 24, 2006
WEYBURN, SASK. – Farmers are seeding their fields in the Prairie sunshine and a meadowlark is singing from a nearby power line.
But Dave Craigen of EnCana oil and gas and his visitors are fixated on the elaborate maze of pipes and drill holes 1.5 kilometres underfoot that has turned southeast Saskatchewan into a mecca for people searching for solutions to global warming.
“You name a country, and they’ve been here,” Mr. Craigen says of EnCana’s $1.5-billion Weyburn operation, which is home to the largest carbon-storage project on the planet.
The $42-million international project is financed largely by Natural Resources Canada and the U.S. Department of Energy. Government and industry officials from Japan, Saudi Arabia, France and the United States have trekked here for a first-hand look. Environment Minister Rona Ambrose, who has promised a “made-in-Canada” plan to cut greenhouse gas emissions, is expected in June.
Since 2000, more than seven million tonnes of carbon dioxide that would otherwise have wafted into the atmosphere have been injected into the porous rock far beneath the farmers’ fields. Plans call for at least 30 million tonnes to eventually be stashed here — the equivalent of taking about 6.8 million cars off the road for a year. The plan — and hope — is that the CO2 will stay locked underground forever.
The Weyburn project and one injecting a million tonnes of carbon dioxide a year under the North Sea are held up internationally as evidence that carbon storage, or sequestration, can work. Geologists say Canada is blessed with huge sedimentary basins that have the potential to hold mind-boggling volumes of the gas.
“We’d run out of fossil fuels before we’d run out of storage space,” says geologist Malcolm Wilson of the University of Regina.
On a global scale, scientists estimate there is room to bury the entire world’s CO2 emissions for hundreds of years. The carbon dioxide buried here is imported from a U.S. gasification plant that produces a steady stream of almost pure CO2. It is captured before it heads up the smoke stack in North Dakota and diverted into a 323-kilometre pipeline. It snakes its way through a lake and across the border into Saskatchewan, where it emerges from the ground at EnCana’s Weyburn operation. The CO2 then heads for a cavernous building where deafening compressors further liquefy the CO2 for injection.
EnCana official Dave Hassan, in charge of the Weyburn operation, likens it to “turning the smokestack upside down.”
The reality is more complicated. The liquid CO2 is fed through a maze of piping buried at the 180-square-kilometre operation. Injection wells, housed in igloo-shaped fibreglass sheds, send the CO2 underground, where it floods into horizontal channels bored into oil-rich rock. The CO2 seeps into the rocks’ pores and acts like a solvent liberating oil. The oil migrates to collection wells and is pulled to the surface by hundreds of pump jacks bobbing up and down on the farmers’ fields.
Much of the CO2 stays underground, but about 2,500 tonnes a day return with the emulsion of oil and water roaring up the production wells. The carbon dioxide bubbles out of the mixture like fizz in a can of pop. It is routed to the compressors, turned back into liquid and reinjected far below the fields where cattle graze and wheat and canola grow. The closed loop, which cost about $1.5- billion to build, generates 30,000 barrels of oil a day. “It’s a simple process, just a big simple process,” Mr. Craigen says.
Injecting CO2 has paid big dividends for EnCana. It has boosted production here to 30,000 barrels of oil a day and extended the life of the Weyburn reservoir by decades. When the wells eventually run dry, it is predicted at least 30 million tonnes of CO2 will be entombed underground. The more than 1,000 wells on the site will be filled in with cement.
Geologists say there is no danger of a catastrophic C02 release like the one that belched out of Lake Nyos in Cameroon in 1986. The gas, which is heavier than air, settled in a thick layer over the surrounding area, asphyxiating 1,700 people and countless animals as they slept.
“You can’t get a Lake Nyos here,” says Mr. Wilson, noting such deadly releases can only occur with deep, tropical lakes in volcanic regions.
The concern on the Prairies is with CO2 seeping from faulty wells and rock fractures, risks that can be minimized and managed, says Michael Monea, executive director of the Petroleum Technology Research Centre co-ordinating the Weyburn research project.
The researchers say the rocks under the Prairies are like a “layer cake” made of sediments laid down over the eons as glaciers and oceans came and went. Some are porous and filled with oil — like the 23-metre-thick reservoir under Weyburn. Others are impenetrable slabs like the five-metre-thick cap rock that keeps the oil in place. “It’s sealed the oil down there for more than 55 million years,” Mr. Wilson says.
Most enticing for carbon storage are the thick layers of porous rock that hold salt water — the so-called saline aquifers that Mr. Monea says offer the “granddaddy” of storage. Unlike oil fields, aquifers have had few wells drilled into them so pose less risk of leaks. To demonstrate the potential, Mr. Monea and his group are proposing a $59-million project to inject 1,350 tonnes of CO2 a day two kilometres down into a Saskatchewan aquifer.
There is also interest in following EnCana’s lead and using CO2 to boost production from oil-bearing rocks. It is estimated CO2 could liberate 3.8 billion extra barrels of oil in Western Canada alone.
© National Post 2006


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