Tweet
THis article highlights how oil development can be carried out that actually helps the environment. The article highlights the limitations of CO2 injection so this is no solution .. . . but anything that eliminates in one day the amount of CO2 that 1000 cars produce in a year is worthy of a look.
win win
Old oil fields rejuvenated: Waste gas pumped deep into the earth helps drillers get more oil
The Vancouver Sun 26 September 2006
By Don Cayo
It sounds too good to be true. Take tonnes and tonnes of carbon dioxide -- a byproduct of burning, and the world's most abundant greenhouse gas -- and secrete it out of sight, out of mind, out of harm's way forever. While you're at it, make money.
That's the premise behind a new enhanced oil recovery technique called CO2 sequestering -- pumping the waste gas deep into the earth where pressure causes most of it to liquefy and eventually solidify. But some of that CO2 actually mixes with the oil and lets the drillers tease out much more than could be pumped by any other affordable technology.
This is a win-win approach, making money while it protects the atmosphere from nasty emissions.
So is it as good as it sounds? Or is it really too good to be true?
Four years into a project to bury up to 30 million tonnes of CO2 and pump out a lot of extra oil from an aging oil field surrounding this southeastern Saskatchewan city, the answer to both questions seems to be yes. Yes, CO2 sequestering and enhanced oil recovery can work in tandem, both from an efficiency and an economic viewpoint. And yes, the problem of CO2 emissions fouling the atmosphere will be around for a long time yet, no matter how common this technique becomes.
The positive proof is in the rejuvenation of Encana's old oil fields around here as a result of the world's largest sequestering/enhancement experiment. It works so well that both Encana and Apache, a competing company, are vying to buy more CO2 from what is so far the region's only supplier, a U.S. company that used to spew it into the air.
But three catches are almost certain to prevent this technology from ever becoming a panacea for greenhouse gas emissions.
The first is that enhanced oil recovery requires clean CO2, unmixed with other waste gases. Yet in the real world, almost all CO2 emissions are anything but pure. They can be cleaned up, but the current technology costs more than the results are worth.
A second problem is that it's only practical to capture, let alone clean up, CO2 emissions from stationary sources -- fossil-fuel burning power generators are the best example. Yet a huge volume of greenhouse gas comes from the fuel that's used in transportation -- cars and trucks, ships and planes, even trains.
Finally, if most or all CO2 emissions could be captured and cleaned up, then there'd be hundreds of times more of the stuff than all the world's oil fields could profitably absorb. It might still be possible to bury the waste gas, clean or dirty, with no harmful consequences. But without the enhanced oil recovery this would cost money, not make it.
Still, the Weyburn project is making a difference, and showing promise of greater future impact.
Daily since 2002, says Koorosh Asghari, project leader for the sequestering research team at Regina's Petroleum Technology Research Centre, the giant Encana gas and oil company has piped in 5,000 tonnes of CO2 from a North Dakota power plant and pumped it about 1.5 kilometres into the ground. That's the daily equivalent of the annual CO2 output of 1,000 typical cars.
The Weyburn field, the world's third-largest conventional oil field, is 52 years old and peppered with old wells, many of them dry for years, Asghari said.
Yet a huge amount of oil -- about 70 per cent of the total reserve -- remains trapped in the porous rock deep underground when conventional extraction has pumped all it can.
Pumping CO2 into strategically placed holes to displace some of the trapped oil is a variation of an old trick -- pumping down water -- which has been done here for years. But the CO2 has a key difference, Asghari said.
Oil and water don't mix, but oil and liquefied CO2 do. The resulting mixture flows more readily than the crude oil, which tends to remain locked in tiny rock pores even when flooded with water.
Over a few months the CO2/oil mixture percolates through to surrounding wells and is pumped to surface. About 20 per cent of the CO2 comes back to the surface in this reinvigorated flow of oil, and it's immediately extracted and pumped back down again.
Asghari said the immense pressure underground keeps the CO2 that doesn't come up with the oil in a liquid state, and eventually it calcifies and becomes a solid.
"This is actually nature's way of getting rid of CO2. We just speed it up,"
Encana keeps the figures on the value of its enhanced production, as well as the price it pays for the CO2, close to its vest.
But the project is working well enough, says David Hassan, who runs the project for Encana, that his company is bidding to get more CO2 from its current supplier, and it's looking around for other potential sources.
The sole supplier at the moment is a coal gasification plant in Beulah, North Dakota, that was built during the 1980s as an environmental demonstration project. Nevertheless, until 2002 Dakota Gas spewed its CO2 waste straight up the smokestack.
The plant currently has two compressors that push the gas through a 30-centimetre, 320-kilometre pipeline to the Weyburn field. It's about to add a third compressor to increase the flow by about 2,500 tonnes a day -- the daily equivalent of the annual output from another 500 cars. This additional CO2 will be split between Encana and Apache Corp., which has wells adjacent to Encana's.
"That'll be about it for the easy CO2 from Dakota," Hassan said. And other sources are, at the moment, few and far between.
The advantage of buying from a coal gasification plant is that it produces a clean CO2 stream.
From conventional power plants, CO2 typically makes up less than a sixth of total emissions which, like the air that provides oxygen for combustion, is largely nitrogen. And nitrogen, if injected into an oil field, actually makes the oil harder to extract.
There are some other producers of relatively pure CO2, Hassan said -- some oil sands upgraders, some refineries and fertilizer plants, for example.
But most CO2 emissions are impure and have no commercial value, and Hassan wonders if people will pay up to 50 per cent more to capture and dump this waste.
"The hurdle's not technological. It's economic and social."
Though oil fields could never productively absorb all of North America's waste CO2, Mike Monea, executive director of Saskatchewan's Petroleum Technology Research Centre, says depleted oil fields in the West could still use a lot more CO2.
He said a conservative estimate is that 400 million barrels of additional oil can be obtained this way in Saskatchewan alone.
Alberta would be four to five times bigger, though B.C. "is a little trickier. It's in a more techtonically active area, and we like stable areas to store our CO2."
Of course, this need not mean that B.C.'s doomed to spew CO2 into the atmosphere for all time. The Earth is rife with good storage locations, Monea said.
One thing that makes oil-field storage desirable and safe, he said, is that oil deposits are always covered by "aquatards" -- geological strata that prevent the upward seepage of not only the oil that has been there for millions of years, but also stored CO2 or water. These impermeable layers also cover many underground aquifers, as well as natural gas deposits.
Asghari said Canada has enough good geological formations to store 2.4 trillion tonnes of CO2. In a world were total emissions total 600 million tonnes a year, that's enough to last through four millennia.
"So we could store it all."
The Vancouver Sun 26 September 2006
By Don Cayo
It sounds too good to be true. Take tonnes and tonnes of carbon dioxide -- a byproduct of burning, and the world's most abundant greenhouse gas -- and secrete it out of sight, out of mind, out of harm's way forever. While you're at it, make money.
That's the premise behind a new enhanced oil recovery technique called CO2 sequestering -- pumping the waste gas deep into the earth where pressure causes most of it to liquefy and eventually solidify. But some of that CO2 actually mixes with the oil and lets the drillers tease out much more than could be pumped by any other affordable technology.
This is a win-win approach, making money while it protects the atmosphere from nasty emissions.
So is it as good as it sounds? Or is it really too good to be true?
Four years into a project to bury up to 30 million tonnes of CO2 and pump out a lot of extra oil from an aging oil field surrounding this southeastern Saskatchewan city, the answer to both questions seems to be yes. Yes, CO2 sequestering and enhanced oil recovery can work in tandem, both from an efficiency and an economic viewpoint. And yes, the problem of CO2 emissions fouling the atmosphere will be around for a long time yet, no matter how common this technique becomes.
The positive proof is in the rejuvenation of Encana's old oil fields around here as a result of the world's largest sequestering/enhancement experiment. It works so well that both Encana and Apache, a competing company, are vying to buy more CO2 from what is so far the region's only supplier, a U.S. company that used to spew it into the air.
But three catches are almost certain to prevent this technology from ever becoming a panacea for greenhouse gas emissions.
The first is that enhanced oil recovery requires clean CO2, unmixed with other waste gases. Yet in the real world, almost all CO2 emissions are anything but pure. They can be cleaned up, but the current technology costs more than the results are worth.
A second problem is that it's only practical to capture, let alone clean up, CO2 emissions from stationary sources -- fossil-fuel burning power generators are the best example. Yet a huge volume of greenhouse gas comes from the fuel that's used in transportation -- cars and trucks, ships and planes, even trains.
Finally, if most or all CO2 emissions could be captured and cleaned up, then there'd be hundreds of times more of the stuff than all the world's oil fields could profitably absorb. It might still be possible to bury the waste gas, clean or dirty, with no harmful consequences. But without the enhanced oil recovery this would cost money, not make it.
Still, the Weyburn project is making a difference, and showing promise of greater future impact.
Daily since 2002, says Koorosh Asghari, project leader for the sequestering research team at Regina's Petroleum Technology Research Centre, the giant Encana gas and oil company has piped in 5,000 tonnes of CO2 from a North Dakota power plant and pumped it about 1.5 kilometres into the ground. That's the daily equivalent of the annual CO2 output of 1,000 typical cars.
The Weyburn field, the world's third-largest conventional oil field, is 52 years old and peppered with old wells, many of them dry for years, Asghari said.
Yet a huge amount of oil -- about 70 per cent of the total reserve -- remains trapped in the porous rock deep underground when conventional extraction has pumped all it can.
Pumping CO2 into strategically placed holes to displace some of the trapped oil is a variation of an old trick -- pumping down water -- which has been done here for years. But the CO2 has a key difference, Asghari said.
Oil and water don't mix, but oil and liquefied CO2 do. The resulting mixture flows more readily than the crude oil, which tends to remain locked in tiny rock pores even when flooded with water.
Over a few months the CO2/oil mixture percolates through to surrounding wells and is pumped to surface. About 20 per cent of the CO2 comes back to the surface in this reinvigorated flow of oil, and it's immediately extracted and pumped back down again.
Asghari said the immense pressure underground keeps the CO2 that doesn't come up with the oil in a liquid state, and eventually it calcifies and becomes a solid.
"This is actually nature's way of getting rid of CO2. We just speed it up,"
Encana keeps the figures on the value of its enhanced production, as well as the price it pays for the CO2, close to its vest.
But the project is working well enough, says David Hassan, who runs the project for Encana, that his company is bidding to get more CO2 from its current supplier, and it's looking around for other potential sources.
The sole supplier at the moment is a coal gasification plant in Beulah, North Dakota, that was built during the 1980s as an environmental demonstration project. Nevertheless, until 2002 Dakota Gas spewed its CO2 waste straight up the smokestack.
The plant currently has two compressors that push the gas through a 30-centimetre, 320-kilometre pipeline to the Weyburn field. It's about to add a third compressor to increase the flow by about 2,500 tonnes a day -- the daily equivalent of the annual output from another 500 cars. This additional CO2 will be split between Encana and Apache Corp., which has wells adjacent to Encana's.
"That'll be about it for the easy CO2 from Dakota," Hassan said. And other sources are, at the moment, few and far between.
The advantage of buying from a coal gasification plant is that it produces a clean CO2 stream.
From conventional power plants, CO2 typically makes up less than a sixth of total emissions which, like the air that provides oxygen for combustion, is largely nitrogen. And nitrogen, if injected into an oil field, actually makes the oil harder to extract.
There are some other producers of relatively pure CO2, Hassan said -- some oil sands upgraders, some refineries and fertilizer plants, for example.
But most CO2 emissions are impure and have no commercial value, and Hassan wonders if people will pay up to 50 per cent more to capture and dump this waste.
"The hurdle's not technological. It's economic and social."
Though oil fields could never productively absorb all of North America's waste CO2, Mike Monea, executive director of Saskatchewan's Petroleum Technology Research Centre, says depleted oil fields in the West could still use a lot more CO2.
He said a conservative estimate is that 400 million barrels of additional oil can be obtained this way in Saskatchewan alone.
Alberta would be four to five times bigger, though B.C. "is a little trickier. It's in a more techtonically active area, and we like stable areas to store our CO2."
Of course, this need not mean that B.C.'s doomed to spew CO2 into the atmosphere for all time. The Earth is rife with good storage locations, Monea said.
One thing that makes oil-field storage desirable and safe, he said, is that oil deposits are always covered by "aquatards" -- geological strata that prevent the upward seepage of not only the oil that has been there for millions of years, but also stored CO2 or water. These impermeable layers also cover many underground aquifers, as well as natural gas deposits.
Asghari said Canada has enough good geological formations to store 2.4 trillion tonnes of CO2. In a world were total emissions total 600 million tonnes a year, that's enough to last through four millennia.
"So we could store it all."
win win
Good your previous response made no sense since this is something that oil companies are doing voluntarily since it increases the amounts of oil they can extract. The "polluter" actually makes money from their CO2.
Comment