Coal Seam Methane Gas (CBM)
What is Coal Bed Methane Gas?
Coal bed methane gas (CBM or coal seam methane), as the name suggests, is a by-product of the geological processes that created our waste deposits of coal. It's original name was firedamp because it is the most dangerous of the explosive mine gases. Some coal measures contain more gas other contain less.
Wikipedia, the free encyclopedia, defines CBM as: "Also called coal bed gas, the term refers to methane adsorbed into the solid matrix of the coal. It is called 'sweet gas' because of its lack of hydrogen sulfide. The presence of this gas is well known from its occurrence in underground coal mining, where it presents a serious safety risk. Coalbed methane, often referred to as CBM, is distinct from a typical sandstone or other conventional gas reservoir, as the methane is stored within the coal by a process called adsorption. The methane is in a near-liquid state, lining the inside of pores within the coal (called the matrix). The open fractures in the coal (called the cleats) can also contain free gas or can be saturated with water."
This coal gas can be extracted by various drilling techniques and used as the natural petroleum gas. For an authoritative review see this complete Wikipedia page Extraction of CBM.
Frequently Asked Questions - Coal Bed Methane (CBM)
Environmental Hazards of Coal Gas
Promoters of the coal gas extraction take a lot of of trouble to present their fledgling industry as very "green", harmless to the environment, "the way ahead", "clean coal technology" and so on. Unfortunately, despite all the skillful spin, the reality is different. Overseas experiences, particularly those from the USA, show that gas mining is associated with numerous environmental hazards. We have to be extremely careful because the environmental damage could easily exceed any expected benefits.
Threats in General
Website of the Australian Gas Alliance
Letter to Bureau of Land Management, Buffalo, Wyoming,
Climate changes methane gas leaks, CO2 info http://www.cs.ntu.edu.au/homepages/jmitroy/sid101/uncc/fs027.html
Coal bed methane alert (Sydney gas gets a mention). http://www.ticora.com/cbmalerts/CBMAlertMay2001.pdf
Threats to Underground Water Resources
INFORMATION ABOUT COAL BED METHANE GAS http://waterquality.montana.edu/docs/methane/cbmfaq.shtml
Threats to Surface Water
Possible Air Pollution
Social Effects of Coal Gas Mining
For some reasons promoters of the coal gas mining prefer to move into undisturbed areas inhabited by small rural communities. Experience overseas shows that this could have devastating effects on them for many reasons. This can be best illustrated by several streaming video clips from Colorado and Wyoming, USA. They deal mainly with effects of the natural gas (propane) exploration but the social and environmental effects would be very similar to those of the coal bed methane. Colorado and Wyoming are two gas exploration boom states and their local paper Rocky Mountains News run on 12 December, 2007 a fascinating feature entitled
The video interviews with local residents are at the
top on the right hand side of the page. They are something not to be
missed because these clips may well represent a glimpse into
our future. There is, of course, one vital difference: in Australia the land owners
do not get royalties from the gas companies so probably
not too many "haves" will be created here. The
Rocky Mountains scenery in the clips is stunning and the
tolerance of Americans to the environmental damage amazing. Do not miss
reading the readers comments at the bottom of the page - very
educational. They may be real or they may be a work of some public
relation firm hired by the oil companies. There is no doubt that the
social effects of gas exploration could be very complex.
CBM Development, Ranching And Agriculture A public testimony of Nancy Sorenson a rancher from Wyoming, USA. A story of a broken dreams ...
Coal Gas Extraction in Australia
The history of coal gas mining in Australia is relatively short but quite turbulent. We are only second to the USA in commercialization of the coal gas methane resources.
In NSW there is a small gas field south of Sydney at Camden. This was originally established by Woodside Petroleum Company and subsequently sold to Sydney Gas Limited and Australian Gas Limited consortium. Sydney Gas subsequently tried unsuccessfully establish a gas field west of Wyong. At present they are trying again in the Hunter Valley Bulga-Broke area.
In Central Qeensland, where they operate under the Coal Mining Act, they are more succesful. See the article presented by the Australian Coal Association. It should be noted that they do not operate in densely populated rural residential areas.
and Climate Change - Methane Capture and Use
GAS PROJECT - STAGE 2 COAL SEAM METHANE EXTRACTION. PROPOSAL BY SYDNEY
GAS OPERATIONS PTY LTD
Bed Methane Hazards in New South Wales
ABC RADIO INTERVIEW WITH KERRY HICKEY ABOUT WYONG PROJECT http://www.abc.net.au/rn/talks/bbing/stories/s1392759.htm
Mining Mismanagement in Pilliga, NSW http://www.npansw.org.au/web/news/media/050331_Mining_Mismanagement_in_Pilliga.htm
New Gas Pipeline to deliver jobs and cut greenhouse http://www.planning.nsw.gov.au/mediarelplan/fs20060928_420.html
Coal Gas and Government Departments
Governments at all levels are in difficult positions. From one side they are under pressure from the mining companies to give them unlimited access to the land under their juristriction. On the other side they are the voters who require protection of the environment and their citizen rights. They do not always succeed in taking a responsible and balanced view.
MAYORAL MINUTE - METHANE GAS PROPOSAL IN WYONG SHIRE RURAL VALLEYS http://www.wyongsc.nsw.gov.au/about/meeting_paper_241104.pdf
Government Cover-up http://www.parliament.nsw.gov.au/prod/parlment/hansart.nsf/V3Key/LC20021112007
Coal Gas Extraction Overseas
The CBM industry started in the USA in the early eighties. These early days could be characterized by a complete disregard of any environmental concerns - saline waste waters were allowed to drain into rivers and escaped gas resulted in a constant smelly haze over the rangelands of Wyoming and Montana. Lately there were some improvements due to the state government regulation but there is still a long way to go. several new CBM projects are currently under consideration especially in USA, Canada and Indonesia.
POWDER RIVER BASIN WEBSITE ON COAL
BED METHANE GAS
Coal Bed Methane Monitor
CBM and the Existing Coal Mines
When the coal deposits are disturbed by open cut mining the gas simply escapes into the atmosphere. In underground mines the coal gas represents a serious danger to the miners because the explosive mixture of methane and air is extremely dangerous. It has to be moved by mine ventilation systems into the open air and either released or flared. Since methane is 24 times more effective as a greenhouse gas then the carbon dioxide releasing it atmosphere is highly damaging and irresponsible. Flaring the methane is better but also a waste of a valuable resource. Extraction of the methane from the existing coal mine leases is a more attractive proposition. Both industries are therefore inexorably linked and should be treated as one.
A NEW longwall project north of Wyong http://www.longwalls.com/storyview.asp?storyid=69779§ionsource=s225 A NEW longwall project north of Wyong in New South Wales has recently been submitted for project application approval – the first of many needed before an expected longwall ramp-up in 2010. Wallarah 2 Coal Project (W2CP) environment and community manager Peter Smith told International Longwall News how the project was progressing.