Green Car Congress  
Go to GCC Discussions forum About GCC Contact  RSS Subscribe Twitter headlines

« University of Michigan to build test facility for connected and automated vehicles | Main | DuPont calls on EU and German authorities to complete HFO-1234y work; “high time to get final clarity” »

Print this post

U. Calgary analysis of energy balances and emissions of SAGD oil sands production finds need for improved processes; some operations not thermally efficient or net generators of energy

19 October 2013

Sagd
Plot of cumulative steam-to-oil ratio (cSOR) vs. ratio of energy produced in form of chemical energy contained in bitumen if combusted to energy injected in form of steam (75% efficient steam generation). From Gates and Larter (2013). Click to enlarge.

A team at the University of Calgary has assessed the thermal efficiencies, energy balances, and emissions of Steam-Assisted Gravity Drainage (SAGD)—both theoretically and as deployed at scale, using field data from the ERCB—for the production of bitumen from Athabasca oil sands reservoirs. In a paper in the journal Fuel, they report that current SAGD projects in Alberta show a very wide range of field performance.

Although optimized SAGD can yield “reasonably high” recovery factors, they found, the economic and environmental costs can be large given the amount of steam required. The data suggests that at the extreme, some operations are actually not net energy generating—i.e., the energy injected via steam exceeds the recovered chemical energy in the retrieved bitumen. The results suggest that in situ bitumen recovery processes need to advance well beyond current capabilities “if practical and sustainable energy balance and emissions scenarios are to be achieved,” they said.

One of the key challenges in producing bitumen and heavy oil is their high, variable viscosity. Heavy oil (between 10° and 20° API) has a dead oil viscosity ranging up to the thousands or tens of thousands of cP. Bitumen (<10° API) has viscosities ranging from the tens of thousands to more than 10 million cP at reservoir conditions.

However, when heated to steam temperatures, bitumen’s viscosity drops by several ordes of magnitude. For a typical Athabasca bitumen, the researchers note, the dead oil viscosity at 100 °C is equal roughly to 220 cP.

For a successful in situ oil sands bitumen recovery process, two requirements must be met: first, it is necessary to raise the oil mobility (often done by lowering its viscosity which results from raising its temperature) until it can be moved by natural forces such as gravity, and secondly, it is necessary to move the mobilized oil to a production wellbore so it can be produced to the surface.

Currently, commercial steam-based in situ processess used to recover bitumen from oil sands reservoirs are either one of Cyclic Steam Stimulation (CSS), or Steam-Assisted Gravity Drainage (SAGD). In this work, we will focus on SAGD although the analysis and results, conceptually, also apply to CSS.

—Gates and Larter (2013)

Operator experience is clearly an important factor but reservoir geology is king!
—Gates and Larter

The geology of the reservoir is a key factor, the two researchers explain. Production reservoirs are “completely different” from the homogeneous sandstones with uniform fluids envisaged by the engineers that developed SAGD.

Geological heterogeneity impacts the recovery process through permeability changes of the reservoir sandstones within the oil column and the shale or mudstone barriers and baffles that prevent or retard fluid flow, respectively. The more laterally extensive the barrier, the longer it takes steam or production fluids to go around it and the longer it taks for mobilized oil to get to the production well. Also, non-productive reservoir within the oil column represents a heat sink which erodes the thermal efficiency of the provess. The main impact of fluid compositional heterogeneity is the due to effect of vertically and laterally varying oil phase viscosity...Thus, during SAGD production, both permeability and oil viscosity variations are important and adversely impact theoretical SAGD productivity.

—Gates and Larter

Nonetheless, while average recoveries for cold heavy oil production range from 5% to 15%, average SAGD recovery factors are between 40% to 60%.

Gates and Larter calculated the theoretical steam to oil ratio (tSOR) required to mobilize the oil to its flow viscosity, given the porosity and fluid saturations. The lower the porosity, the higher the tSOR; the lower the oil saturation, the higher the tSOR.

They then used the tSOR to calculate the theoretical amount of carbon dioxide emitted per unit volume recovered bitumen (tCOR). Their results showed that the amount of CO2 emitted per unit volume oil produced is large; for a steam recovery process operating at about 3000 kPa, under ideal heating conditions, just more than 0.2 tonnes of carbon dioxide are emitted per cubic meter of bitumen recovered for 0.6 steam quality provided to the edge of the chamber.

Using public data, they then examined cumulative steam-to-oil (cSOR) ratios versus time for all major SAGD operations in Alberta by project and by field. They found that although there has been a reduction in the cSOR with time, the cSOR is leveling off for most operations at values above 2 m3/m3.

They found that in general, the best performing well pairs are from regions with better quality reservoir which have thick, highly oil saturated accumulations with few shale barriers and high vertical permeability throughout the reservoir.

They calculated that the energy breakeven point—the point at which the chemical energy output from combusting the bitumen to the energy input in the form of steam—is at cSOR values equal to around 11.5 m3/m3, for the recovery process alone. This means that above this cSOR, the SAGD process is a net energy consumer and thus is not an energy generation process.

After accounting for the energy required (and the bitumen lost) during the upgrading process to convert the bitumen to synthetic oil, and then refining into transportation fuels, they found that the overall breakeven point was equal to a cSOR of about 6.5 m3/m3.

Based on the cSOR field data...many operations exceed this value and thus are not net energy generation processes yet may be “economic”! With disconnected price markets for natural gas and bitumen, it is possible for bitumen recovery under these conditions to be economically viable today even though it makes no sense to pursue such an energy inefficient process when cSOR values are high.

—Gates and Larter

In all cases, they found, carbon dioxide intensity is high and grows significantly as cSOR increases.

The analysis shows that although some SAGD operations are achieving good steam-to-oil ratios, many are not achieveing thermally efficient operation, with cumulative steam-to-oil ratios many times the theoretical vallue. This results from combinations of geological realities, operator decisions and the limitations of the SAGD process.

The results demonstrate that on an energy and carbon dioxide emissions basis, bitumen or bitumen-based energy recovery processes need to step well beyond the capabilities of current steam-based bitumen recovery process, such as SAGD, if practical and sustainable energy balance and emissions scenarios are to be achieved from the in situ oil sands operations.

—Gates and Larter

Financial support for the work was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), Carbon Management Canada and the Canada Research Chairs program.

Resources

  • Ian D. Gates, Stephen R. Larter (2014) “Energy efficiency and emissions intensity of SAGD”, Fuel, Volume 115, Pages 706-713 doi: 10.1016/j.fuel.2013.07.073

October 19, 2013 in Emissions, Oil sands | Permalink | Comments (54) | TrackBack (0)

TrackBack

TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a00d8341c4fbe53ef019b0025485b970d

Listed below are links to weblogs that reference U. Calgary analysis of energy balances and emissions of SAGD oil sands production finds need for improved processes; some operations not thermally efficient or net generators of energy:

Comments

Even if the process is energy-negative, it works as arbitrage; natural gas is currently very cheap in North America, but bitumen sells for nearly as much as crude oil.  It doesn't matter what the energy ratio is so long as it's cash-flow positive.

Two things could change this:

  1. A large increase in NG consumption, such as export terminals or mass conversion of vehicles to CNG/LNG, making gas-fired SAGD uneconomic.
  2. The use of carbon-free technology, such as the LEADIR lead-cooled reactor, to supply the steam for SAGD (and also free the natural gas for other uses).

Three things:

A drop in EV/PHEV cost along with an increase in range. That would be a market killer for petroleum.

Four things:

Carbon pricing. That, and the removal of the subsidies which are typical of the fossil fuel industry.

David LeBlanc, one of the leading lights in the development of high temperature, molten-salt-fueled nuclear reactors, has formed Terrestrial Energy in Canada with a view to (among other things) provide cheap process heat for the tar sands. Check out:

http://www.terrestrialenergyinc.com/

It will be truly ironic if development of the most carbon-intense fossil fuel help us develop one of the most promising zero-carbon energy sources.

Nick,

Amen to that. The tar sand industry has the money required to back this kind of research.

I read a highly interesting book written by two key persons from the Argonne fast breeder program (there is a name invented to scare people, although both 'fast' and 'breeder' refer to aspects that are benign and ultimately improve the safety of nuclear energy) by using metal fuel rather than oxide fuel, and a lot of clever engineering. The program was shut down in the mid-nineties by the Clinton adm. for political reasons (their words), just as they were ready to finally demonstrate the whole value chain. Their reactor would basically be capable of powering humanity for decades on existing nuclear waste and leave near-zero waste in the process.

The problem with using zero-carbon emission energy to get more 'petroleum' out of the ground is that increasing utilization of global oil resources (estimated by USGS and agreed by peak oil community to be roughly 6000 billion barrels of original oil in place) from 2000 to 3000 billion barrels will result in an additional CO2 concentration in the atmosphere of 60 ppm (roughly), which appears to be more than desirable, even disregarding other anthropogenic CO2 sources.

(1·10^12 bll = 1.45·10^14 kg oil = 1.13·10^14 carbon = 9.5·10^12 kmol carbon

Weight of atmosphere: 4·pi·(6·10^6 m)^2 = 4.5·10^14 m2. Each square meter holds about 10 metric tonnes, thus: 4.5·10^18 kg air. Average molar mass of air: 29 kg/kmol, thus: moles of air: 1.56·10^17 kmol air. Marginal concentration of extra CO2 = 9.5E12/1.56E17 = 61 ppm.)

Anyway, developing safe, abundant, low-waste, proliferation resistant nuclear with the objective of providing more fossil petroleum seems to be worth it overall. The gains are greater than the pains. (because nuclear power 'too cheap to meter' might ultimately discourage people from producing all the oil more than any political scheme)

@Thomas Pedersen:

'...nuclear power 'too cheap to meter' might ultimately discourage people from producing all the oil more than any political scheme...'

As an optimist, this is the scenario I am hoping for. Economics will trump policy.

I believe the established projects, Cenovus, Esso, CNRL all have respectable steam to oil ratios under 3:1 and they represent most of the in-situ production in Alberta. There are a few facilities that struggle and I believe much of this can be attributed to difficult geology. I think its a bit misleading to use the phrase 'many operations exceed this value' as they may be many in number however their overall production is less significant.

Bruce Power shelved a proposal to built a nuclear facility in the Peace River area about two years ago. The proposal was intended to serve the rising energy demands of the oil sands. The main reason for suspending/ abandoning may have been due to natural gas prices but opposition from locals as well as environmental groups probably played a role too. Even in western Canada where we mine uranium and the infamous oil sands, building a nuclear power plant seems like a non starter.

Natural gas looks like it would work as a transportation fuel for many applications and be easily justified based on economics yet its adoption seems slow; which leads me to expect that adoption of hybrid and electric vehicles will be also be slow even when they are competitive on an economic basis. Governments may become more active in promoting their favorite fuels and energy. It will be interesting to watch how USA, China, Russia, Saudi Arabia, EU and Japan play their cards.

@Calgarygary, re: steam to oil 3:1

Your statement is correct from the data I have seen

@Thomas Pedersen

You're referring to the PRISM reactor. People that I know in the nuclear industry tell me that GE is going to file with the NRC for a design certification with an eye to having a prototype reactor online sometime around 2020. The same people tell me that GE can make a mint by reprocessing spent fuel. Supposedly, the government has a rather large and stagnant fund that the nuclear industry has been paying into since its inception to pay for fuel remediation. It would GE's pearl if they bring a commercial PRISM reactor online... not to mention they might make some money selling electricity into the grid while they're at it.

@Nick,
I was shocked to think that nuclear reactors could be fueled by molten salt and was headed for the kitchen to check when I realised you were referring to using molten salt as a carrier.(I wouldn't describe a solar thermal plant as salt fueled.) Picky maybe but you'd be suprised how misleading your grammar sounds.


This article describes another example of sheer unabashed greed,and while we all know that is the 'modus operandi' of military democracies (loosely speaking)

I would further make the point from Terrestrial energy website that:

"Molten Salt Reactor (“MSR”) technology is one of the six reactors chosen by the Gen IV International Forum (“GIF”), an international effort to develop a new generation of nuclear power based on civilian needs."

" Due to an early mistaken belief in severe geological limitations of uranium resources, this reactor design was developed as a more demanding form of nuclear reactor, a “breeder.” Breeders create their own fissile fuel when in operation. MSRs are suitable for this role as thorium breeders, but the U.S. government decided to put their sole breeder focus on sodium-cooled fast uranium breeders. Consequently, the MSR program was canceled in the early 1970s. In hindsight, this was a policy error."

I disagree.

The policy accurately enacted the original primary intention of the establishment and ongoing capability of manufacturing fissile material for the purpose of providing lighting in the worlds classrooms?
or was it various forms of w of m d?

I guess it depends on who you believe.
But the fact is politics -we - made an almighty mess and the two most recent disasters in Japan - Actually the public acknowledgement of what was in both cases the end result of a string of negligent activities and attitudes by the leading co in a world leading high technology country.

But if you say it's safe.

I'll move on to the topic.

That is as implied by some commentators that this unproven technology should work as a cure to the other disaster of carbon intensive, BY ANY METHOD, of Tar Sands Mining.

Or if you prefer to believe that carbon pollution is not not real, we could mention the other toxic byproducts that threaten? (currently doing damage to) fisheries,water courses and transport corridors.

Boy, am I glad we have such posting words of wisdom and comfort on this site.
Keep it up guys and I'll grow out of my comforter
-Can't wait to grow up finally.

Regardless the ability or otherwise to add that quantity of carbon and the proven leakage to water courses and inherant risk to any type of transport corridor,this is another example of turning a blind eye to some very dangerous activity for monetary gain.


I was shocked to think that nuclear reactors could be fueled by molten salt and was headed for the kitchen to check when I realised you were referring to using molten salt as a carrier.(I wouldn't describe a solar thermal plant as salt fueled.) Picky maybe but you'd be suprised how misleading your grammar sounds.


This article describes another example of sheer unabashed greed,and while we all know that is the 'modus operandi' of military democracies (loosely speaking)

I would further make the point from Terrestrial energy website that:

"Molten Salt Reactor (“MSR”) technology is one of the six reactors chosen by the Gen IV International Forum (“GIF”), an international effort to develop a new generation of nuclear power based on civilian needs."

" Due to an early mistaken belief in severe geological limitations of uranium resources, this reactor design was developed as a more demanding form of nuclear reactor, a “breeder.” Breeders create their own fissile fuel when in operation. MSRs are suitable for this role as thorium breeders, but the U.S. government decided to put their sole breeder focus on sodium-cooled fast uranium breeders. Consequently, the MSR program was canceled in the early 1970s. In hindsight, this was a policy error."

I disagree.

The policy accurately enabled the primary purpose of manufacture and capability of fissile material for the purpose of providing lighting in third world classrooms?
or was it various forms of w of m d?

Regardless the desirability of reducing the stockpiles of high (or low level) radioactive waste.

I guess it depends on who you believe.

But the fact is politics -we - made an almighty mess and the two most recent disasters in Japan - Actually the public acknowledgement of what was in both cases the end result of a string of negligent activities and attitudes by the leading co in a world leading high technology country.

But if you insist that it's safe.


Or if you prefer to believe that carbon pollution is not not real, we could mention the other toxic byproducts that threaten? (currently doing damage to) fisheries,water courses and transport corridors.

Boy, am I glad we have such words of wisdom and comfort on this site.

"..adoption of hybrid and electric vehicles will be also be slow.."

EV adoption will be slower than some would like. People have been accused of being pro fossil fuel, that the California Low Carbon fuel program is not low enough.

If anyone is depending on EVs to save the day, you may be a bit off the mark. Perhaps 1% of the cars might be EV by 2020, well if California Low Carbon is not low enough, then this EV certainly slow enough.

Apoologies for above posts a result of many unsuccessful attempts to post.
Lessons learned:1; walk away and try later.2;in the meantime refine writing via critical proof reading.
3; learn by mistakes; 4;don't forget to humor the typo!

No problem, an edit feature would be nice.
The last few words of my post should read...

"then the EV (adoption rate) is certainly slow enough."
One misspelled word can change the whole meaning.

You don't need pure EVs; PHEVs are good enough to displace much if not most motor fuel used in LDVs.

What I would like to see is something like LEADIR supplying steam for SAGD, and being retrofitted to coal-fired electric plants (perhaps with gas-fired superheaters).  That would slash fossil-fuel use and carbon emissions, and probably electric prices as well (I understand the cost of TRISO fuel for a LEADIR is about 3x as much as LEU, but that's still only about 2¢/kWh).

Five things:

The emergence of H2-FCV by 2015 that can use H2 made directly from nuclear energy or solar or wind energy. Petroleum use will decline when FCV and PEV will take over the automotive market.

In sunny areas, perhaps PHEV's may be equipped with solar PV panels on all upward-facing surfaces that can supply the vehicle with 1/3 to 1/2 the total energy consumed during the car's lifespan. This will solve the intermittency nature of solar energy as well as providing a convenient surface for mounting of solar PV panels on parking lots without any additional cost of supporting structures. When integrated to a PHEV's body surface, the installation cost of these solar PV surfaces will be next to nothing, while electrical hardwares are already built-in the vehicle.

Common sense dictates that, in the long term, unlimited clean solar energy will replace most other forms of energy generation such as coal, NG, nuclear, wind etc. Hydro may be one of the existing form to stay.

Six things:

Because of climate change drought becomes the new normal and water becomes too valuable to use in bitumen recovery.

PHEVs still need to get the fuel somewhere, biomass can produce synthetic gasoline without the fossil CO2 emissions. But NO, the wise ones say that if it can not provide ALL our fuel it is worthless so forget it.

The next few years are going to be very interesting. We're pretty sure that the cost of EV batteries is largely an economy of scale issue and that the only real issue with very wide spread adoption is range.

If higher capacity batteries come to market in the next five years hydrogen fuel cell vehicles will wither on the vine. The dreams of building large numbers of nuclear reactors to cook gunk out of tar sands and crack water into hydrogen will die away. Petroleum and hydrogen transportation simply can't compete with electricity. That's math.

If we reach an impasse with battery capacity then I'd expect the route will be wind and solar to produce hydrogen. PHEVs using electricity for 90% of the driving and hydrogen fuel cells for the last 10% would likely be our cleanest, least expensive alternative.

Going 100% hydrogen fuel cells would mean tremendous infrastructure buildup, PHEVs would cut that by 90%.

The UK has apparently just decided to build a couple new reactors and is guaranteeing to pay around 15c/kWh for every kWh produced for the next 20 (or more?) years. Plus give the building loan guarantees which put non-completion risks back on the UK taxpayer. We aren't likely to build 15c/kWh nuclear to crack water into hydrogen when we can do the same work with 5c or less wind and solar.

To summarize my views:

Wind and Solar as currently being done are largely a Ponzi scheme. If you can't get more energy out than you put in, it just doesn't make sense.

Hydrogen is not an energy source. It is an energy carrier. Because of it's nature, being difficult to store and transport, it may never be an acceptable fuel.

I live in far Western Wyoming. The nearest Wal-mart, Lowes and Home Depot are 115 miles away. I need transportation that will safely take me 200 miles and back without hours long wait for re-energizing. I doubt that I will ever see a practical EV that would meet my needs.

What we will eventually get hasn't been thought of yet.

Windbag Bob writes:

We aren't likely to build 15c/kWh nuclear to crack water into hydrogen when we can do the same work with 5c or less wind and solar.

5¢?  The UK's current rate for offshore wind farms is GBP155/MWH.  That is more like US23¢/kWh.

The FOAK EPR at Olkiluoto will produce power for around 10¢/kWh amortization O&M.  Experience will lower the cost of later units by quite a bit, and the government guarantees put up by the UK eliminate most of the regulatory risk.

the wise ones say that if it can not provide ALL our fuel it is worthless so forget it.

Nobody said it's worthless.  It's just expensive and limited, and there are higher-value competing uses (e.g. polymers),  Last, building a major chemical plant is a 50-year investment, and battery improvements could radically change the market in ten years or less.  Maybe bio-gasoline is viable in the near future, but if the plants making it can't change their product mix they could wind up as stranded assets.  Given the massive size of the petroleum fuels market compared to polymers, it's likely that most of them would.

It was reported today that energy produced by the two large reactors to be built in south-western England will be $0.15/kWh for the next 35 years. That's very far from the 1 to 2 cents/kWh claimed by many pro-nuclear posters.

Meanwhile, the latest (private) wind farms being built in our area will get 10 cents/kWh and future larger wind turbines will produce energy for about 5 to 6 cents/kWh without radiation leaks/explosion fear.

Low general public acceptance + very high cost (15 + cents/kWh) are major factors against building more nuclear power plants.

Wind 4c/kWh -

"The prices offered by wind projects to utility purchasers averaged $40/MWh for projects negotiating contracts 2011 and 2012, spurring demand for wind energy."

http://www1.eere.energy.gov/wind/pdfs/2012_wind_technologies_market_report.pdf


Solar 5c/kWh -

"The cost of large-scale solar projects has fallen by one third in the last five years and big solar now competes with wind energy in the solar-rich south-west of the United States, according to new research.

The study by the Lawrence Berkeley National Laboratory entitled “Utility-Scale Solar 2012: An Empirical Analysis of Project Cost, Performance, and Pricing Trends in the United States” – says the cost of solar is still falling and contracts for some solar projects are being struck as low as $50/MWh (including a 30 per cent federal tax credit)."

"Another interesting observation from LBNL is that most of the contracts written in recent years do not escalate in nominal dollars over the life of the contract. This means that in real dollar terms, the pricing of the contract actually declines.

This means that towards the end of their contracts, the solar plants (including PV, CSP and CPV) contracted in 2013 will on average will be delivering electricity at less than $40/MWh. This is likely to be considerably less than fossil fuel plants at the same time, given the expected cost of fuels and any environmental regulations."


http://reneweconomy.com.au/2013/big-solar-now-competing-with-wind-energy-on-costs-75962

Nuclear 15c/kWh -

Summary of the apparent agreement for two new nuclear reactors in the UK -

"The strike price is 9.25 pence per kWh, equivalent to around 0.11 euros ($0.15/kWh) at today’s conversion rate.

The price is guaranteed for 35 years.

The price will be adjusted for inflation (i.e., go up)

And reviewed in 7.5, 15, and 25 years to “protect” Hinkley C, as the plant will be called, “from being curtailed without appropriate compensation”

http://www.renewablesinternational.net/uk-grants-feed-in-tariffs-to-nuclear/150/537/74096/

"Experience will lower the cost of later units by quite a bit"

We have 60 years' experience building nuclear reactors and the price does nothing but climb.

If one does a LCOE for Olkiluoto 3 including financing costs (which the Breakthrough Institute "forgets" to include) the price is around 15c/kWh.

The price of both wind and solar should continue to drop over the coming years.

The math. Simply do the math.


Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Green Car Congress © 2014 BioAge Group, LLC. All Rights Reserved. | Home | BioAge Group