Danger - CCS Injection and Leakage

The article, from which these quotes were taken, can be found on the link below (words enhanced to help readers who skim articles)
http://mydocs.epri.com/docs/CorporateDocuments/EPRI_Journal/2007-Spring/1014795_CO2Storage.pdf

While the concept of geologic storage seems simple enough, a CO2 injection well is a surprisingly complicated system. Multiple cement casings and provisions for monitoring are required to ensure that the supercritical fluid reaches only appropriate storage formations and stays there. In particular, steps must be taken to keep the CO2 from interfering with sources of drinking water at shallower depths. In the injection zone itself, special cement must be used to prevent damage to the casing from acids that form when CO2 reacts with the in situ saline solution.

A variety of measurement, monitoring, and verification (MMV) technologies will also need to be incorporated into a complete storage system to make sure the CO2is not leaking into the surrounding environment. Some off-the-shelf technologies,such as seismic imaging of subterranean formations, are already being used to trackthe underground migration of injected CO2, and sampling of groundwater couldprove useful for detecting leakage directly. Detecting small rates of leakage over long periods of time, however, will require higher-resolution measurements and the development of highly precise baseline data. More-sensitive MMV techniques thatcan measure the actual amount of CO2 in storage may also be needed for purposes of greenhouse gas mitigation reporting.

The issue of leakage is critical from both global and local perspectives. Even gradual leakage from numerous sites may provide enough CO2 reentering the atmosphere to undermine efforts to stabilize greenhouse gas concentrations. Locally, leakage from an underground storage site could present an immediate hazard to humans and ecosystems.

The most dramatic type of CO2 release would come from a blow-out at an injection well, which could produce high enough concentrations (7–10%) of the gas in the vicinity to endanger human life.

Undetected leakage from a faulty well or through ground fractures would probably be more diffuse and primarily affect groundwater and surface ecosystems. In particular, aquifers used as a source of drinking water could be harmed, either by acidification resulting from direct contact with large amounts of CO2 or by the seepage of brines displaced by CO2 during the injection process.

Because CO2 is heavier than air, it also could accumulate in lowlying geographic areas or in basements and potentially threaten human health.
Research is currently under way to improve CO2 leak detection and develop possible
remedial measures. Specifically, MMV technologies are needed that would detect
potential leaks long before they pose any danger to water supplies or surface ecosystems.

Seismic imaging, for example, can reveal deep subsurface faulting and abandoned
wells that might permit leakage by providing a route to the surface, and this
type of examination is expected to become a routine part of storage site evaluation. In addition, some experiments are under way to begin to investigate leakage rates for different types of storage and under a variety of injection conditions.

Several kinds of remediation techniques also need to be explored, including the extraction and purification of contaminated groundwater, the interception and reinjection of leaking CO2, and the removal of stored CO2 for injection elsewhere.

“The available monitoring methods are promising, but more experience is needed to establish detection levels and resolution."

”

Risks Related to CO2 Sequestration, - LOTS OF RISKS

This is a great link to a web page that has A LOT OF INFORMATION about the risks associated with CO2 sequestration, also referred to as Geosequestration or "GS" - scroll up and down... you will find it addresses things like - risks to workers, the public, ecosystem, microbes in the ground, drinking water and the contamination it is likely to cause, it is one of the most complete sources of risks that I have seen for CCS ( Carbon Capture and Sequestration)

Click below -
This link is WELL WORTH YOUR TIME!


ADDITIONAL INFORMATION Below -from the web site:
http://solveclimate.com/blog/20090320/ccs-cant-make-tar-sands-clean
Click on the link to read the entire article... bold print is my emphasis.

"Chasing CCS is a money burner and an energy hog, and it may not deliver much carbon savings. The whole reactive proposition raises extreme security and liability issues for industry and taxpayers alike.

It Takes Energy to Bury CO2

The chief obstacle to CCS is cost. Right now, no country buries lots of CO2 because it is not economical. John Pavlish, a senior U.S. researcher on CCS at North Dakota's Energy and Environmental Research Center, notes that CCS would raise the cost of a power plant by 35 to 100 percent which, in turn, would increase electric bills by 30 to 80 percent. Without a $40 to $80 price tag on a tonne of CO2, not much carbon will ever get buried.

It takes a lot energy to capture, compress and inject CO2 into the ground. In fact 30, percent of the power generated by a coal-fired facility or tar sands power plant would be cannibalized by a CO2 retrofit.

That’s great news for coal companies because CCS demands that utilities burn more coal instead of building windmills.

Storage problems

Security of storage is also a concern. Not too many places in North America are suitable for carbon burial due to earthquake risks or high density oil and gas drilling. Improperly sealed wells or faulty cement jobs could invite great volumes of CO2 back to the surface. Leaks could also acidify groundwater.

The Intergovernmental Panel on Climate Change, for example, dutifully notes that Alberta is a pin cushion. With more than 350,000 oil and gas wells, it is one of the most intensely drilled landscapes in the world. In other words, CO2 could find its way back to the surface and into people’s basements and wells.

CO2 injection may also cause man-made earthquakes. The rapid depletion of gas wells and the water flooding of oil wells have caused a series of documented earthquakes in Alberta, Texas and the Netherlands. Geologists call it “induced seismicity.” The largest earthquakes ever recorded in Alberta were triggered by oil and gas activity. Natural Resources Canada recently studied a series of earthquakes caused by sour gas removal at the Strachan gas plant in Rocky Mountain House.

Although the technology for capturing, compressing and piping carbon is doable, not much is known about rapid CO2 injection into old oil reservoirs or salty aquifers.

Independent research by University of Calgary engineer Minzghe Dong shows that each and every reservoir behaves differently and has to be carefully prepared. If most of the oil and water isn’t removed, the reservoir will chemically react with CO2 and limit the amount of disposal space. Scientists have yet to show that the rock cap sealing salt aquifers can actually safely contain CO2.

Liability is no small cross in the carbon cemetery either. Buried CO2 must be monitored for thousands of years, a task few regulators really want to undertake. Industry doesn’t want to invest in CCS until government (read taxpayers) assumes the liabilities of leaks and groundwater contamination. Wyoming, the largest coal producing state, wisely passed legislation that places the liability for the unintended consequences of CCS on the utility or oil company that injects it.

It is reactive program, not a proactive one. The technology costs too much and won't scale up in time to make a difference. It directly robs taxpayers and subsidizes the world’s wealthiest industry. And it steals dollars from renewable programs. What CCS does is give coal and oil companies taxpayer money to accelerate hydrocarbon consumption by nearly one third."

WARNING - CO2 Sequestration Danger - Citizen CALL TO ACTION

WARNING

CARBON DIOXIDE SEQUESTRATION

AN EXPERIMENT WITH CONSEQUENCES

• Two major aquifers will be at risk, threatening our water
• Injection at high pressure can cause earthquakes
• If released in sudden amounts can cause death
• If released in slow amounts can damage nutrient-rich soil
• Turns into an acidic solvent that corrodes pipelines
• No one knows how far it can travel once injected
• Residents can be burdened with unfair liability issues
• Will cost $93 million over a ten-year period

TAKE ACTION

STOP IT NOW!

CONCERNED CITIZENS ACTION MEETING

PUBLIC IS URGED TO ATTEND

Christian Lighthouse Center’s

All Seasons Place

5256 Sebring-Warner Road Greenville, OH – Darke Co.

When: Monday, June 29, 2009

7:00 p.m.

SPEAKERS:

Kerwin Olson,

Citizens Action of Indiana

Dangers of CO2

Kathleen Boutis, President

Green Coalition of Western Ohio

Sponsored by: Citizens Against CO2 Sequestration

citizensagainstco2sequestration.blogspot.com

General hazards of carbon dioxide

This information is from the following web site:
http://www.hse.gov.uk/carboncapture/carbondioxide.htm

"At room temperature and ambient pressure CO₂ is a colourless, odourless gas that will not support combustion or human life. CO₂ has been recognised as a workplace hazard for over a century. It is significantly heavier than air and many fatalities from asphyxiation have resulted from entry into pits, tanks, sumps or cellars where CO₂ has accumulated and displaced oxygen.

It is also possible for dangerous levels of CO₂ to form out-of-doors in trenches, depressions or valleys. This is particularly likely when the gas is colder than the surrounding air, which may occur following pressurised release.

In 2000, a US Environmental Projection Agency study on CO₂ related incidents in fire scenarios reported that since 1975 there were 51 recorded incidents involving the discharge of CO₂ fire extinguishing systems resulting in 72 deaths and 145 injuries.
There is no significant inherent human response to CO₂ that could be useful as a detection mechanism. Human response to hydrogen sulphide by smell occurs at very low (ppm) concentrations, similarly with ammonia and sulphur dioxide.

In contrast, CO₂ is present in the air we breath (0.037%). This may cause problems with instrumented detection because the 'background' CO₂ levels are so high. In addition, the cooling effects of a pressurised CO₂ leak may have an adverse effect on the accuracy and operability of CO₂ gas detection systems.

The recognition of the dangers of CO₂ has prompted much research into its toxicity in both human volunteers and animals. It is now known that, in addition to the problem of asphyxiation due to the displacement of oxygen, the inhalation of elevated concentrations of CO₂ can increase the acidity of the blood triggering adverse effects on the respiratory, cardiovascular and central nervous systems. Data from published research reports has been used by HSE to quantify the toxicity of CO₂ in the form of Dangerous Toxic Load (DTL)¹ values.

The DTLs have been used in calculations by the Health and Safety Laboratories (HSL) to demonstrate that CO₂ exhibits major accident potential, when transported by pipeline in large quantities at ambient temperature and at a pressure of 7 bar or more, well below the dense phase or supercritical region. It is not yet clear whether controls should be applied to the transport of CO₂ in this context but pending further research, it is possible that HSE will propose amending the Pipelines Safety Regulations to include CO₂ as a dangerous fluid.

Additional hazards of dense phase or supercritical carbon dioxide

For economic and technical reasons it is likely CO₂ will be handled close to or above its critical pressure (73.82 bar) where many of its properties are similar to that of a liquid. In this state it is often referred to as a dense phase fluid, whereas above critical temperature (31.04oC) and pressure it is referred to as supercritical. Most of the additional hazards associated with dense phase or supercritical CO₂ arise when this pressure suddenly falls or is lost completely.

Scale of the thermal cooling envelope

In the event pf a major pressure loss, e.g a pipe rupture or containment failure, the depressurisation will result in an increase in the volume occupied by the CO₂ of several hundred fold as the escaping fluid undergoes a rapid expansion (and phase change) as a proportion essentially 'boils' and becomes a gas while the remainder forms solid particles. This rapid, violent expansion causes the temperature of escaping CO₂ to fall very rapidly, frequently below -80°C. while the particles of solid CO₂ formed (dry ice) will result in projectiles expelled at very high velocities.

Cryogenic burns and impact injuries from extremely cold jet of gas and entrained missiles are serious hazards to personnel. Cryogenic embrittlement of structural steelwork and adverse effects from the impingement of extremely cold gas jets on safety-critical equipment are major threats to the structural and functional integrity of nearby plant unless appropriately designed or protected.

Toxic contamination effects

Supercritical CO₂ is a highly efficient solvent. When supercritical CO₂ undergoes a significant pressure reduction it moves from its supercritical state with super solvent properties to a gaseous state with virtually no solvent capability. In any environment where other substances are present with supercritical CO₂ their solvation will occur resulting in fluid medium or "solution" containing various compounds or elements many of which may be extremely toxic. Any toxic substance held in such a pressurised 'solution' will 'precipitate' out on loss of pressure or containment and is likely to result in harmful human exposure or environmental damage due to the contamination of the area of deposition unless appropriate measures are taken.

Dry Ice 'grit blasting effects'

Where captured CO₂ may be present with solid particles such as reservoir-derived sand and other solid debris, loss of containment may result in these combining with the dry ice formed to produce particles of a much greater abrasive capability than dry ice alone. This would enhance the erosion effects on process pipework and vessels adjacent to the leak which could lead to further damage to equipment and hence risk to people.

Specific challenges associated with dense phase or supercritical carbon dioxide

Whilst the processes that make up Carbon Capture and Storage (CCS) are not novel in themselves there is relatively little experience worldwide in managing the risks associated with CO₂, compared with oil and gas. The major accident hazards presented by handling high pressure CO₂ offshore or onshore need to be considered in the context of about 10,000 years' operating experience in managing hazards associated with hydrocarbon processing offshore alone, and probably much more if onshore processes are included². In comparison there are probably less than 100 operating years for handling CO₂ and significantly less in dealing with supercritical CO₂.

Modelling dense phase/supercritical CO₂ releases

The ability to anticipate foreseeable major accident scenarios and accurately predict the consequences of these hazardous events is a fundamental element in the assessment of the risk. A lack of substantial operation experience in a novel process or technology generally leads to significant difficulties in identifying accurately the hazards associated with that process or technology.

We do not yet fully understand the behaviour of CO₂ when released from dense phase. Industry is researching appropriate models which will need to be validated. There is a need for appropriate scale experimental work to provide HSE and duty holders with a thorough understanding of how CO₂ behaves during foreseeable large releases.

Containment and integrity

Whilst there are applicable general engineering standards, there is a lack of internationally recognised standards and codes of practice specifically for dense phase or supercritical CO₂ plant and equipment. When designing, fabricating and maintaining plant for handling and transporting CO₂ it is important that the full significance its physical properties, at the temperatures, pressures and inventories required are fully recognised and managed accordingly. Where applying standards developed for other substances including hydrocarbons, such as natural gas, extreme caution is advised as even the highest standards for many other substances may not be sufficient to ensure adequate containment for CO₂ under the expected, and unexpected operating envelope(s).

Deep-Sixing CO2 Emissions

http://articles.latimes.com/2006/sep/03/science/sci-northsea3?pg=2

"By Robert Lee Hotz
September 03, 2006

Until recently, however, few cared so much about how long the carbon dioxide stayed put.

That is starting to change. Since 2000, the North American energy company EnCana Corp. has boosted oil production 50% at Weyburn, Canada, by injecting millions of tons of surplus CO2 from North Dakota. Plans call for at least 20 million tons in all to be sequestered permanently there in coming decades -- an amount equal to the annual emissions of 6.8 million cars.

So far, monitoring indicates that most of it will stay underground but, by one report, about 2,500 tons a day bubble to the surface where it must be recaptured and re-injected.

Critics of the storage operations worry about the long-term safety of the reservoirs. No one knows whether excess carbon dioxide will remain stable underground for hundreds or thousands of years.

"If it can find any well, crack or conduit in the rock, it will escape," said Harvard carbon storage researcher Kurt Zenz House.

With more than 3.5 million oil wells drilled in the U.S. since petroleum exploration began in earnest 150 years ago, there is no shortage of potential leaks.

Experts also worry how so much carbon dioxide will alter the chemistry of the storage formations themselves. Bubbles composed of millions of tons of sequestered CO2 could form an acid that could etch away the confining rocks or erode the concrete caps on well heads.

To test the effects of carbon dioxide storage, researchers funded by the U.S. Department of Energy recently injected 2,000 tons -- about half a day's power plant emissions -- into a mile-deep well northeast of Houston.

After monitoring the site for two years, researchers at the U.S. Geological Survey found no leaks.

But in a study made public in July, they did discover that the buried CO2 increased the acidity of the saltwater in the rock enough to dissolve the surrounding minerals. Should enough minerals be eaten away, the gas could seep slowly into the atmosphere again, they reported. The acidic solution also could combine with trace metals and organic compounds to contaminate groundwater."