cbm trivia

I thought EPG investors or possible investors may be interested in a bit more info in regards to CBM.

From what I have read CBM production has only been around for approx 25 years and mainly in the USA.

Europe is just becoming aware of the amounts of gas available through this method and EPG is at the forefront.

Happy reading.....

What is coalbed methane?

Coalbed methane (CBM) is the natural gas found in most coal deposits. CBM is created during coalification, the process by which plant material is converted into coal over millions of years. Under most circumstances, CBM consists of pure methane, though it may also contain minor amounts of carbon dioxide and nitrogen. Methane is contained primarily within the coal seam where it is adsorbed (attached) to the coal. Pressure from the overlying rock and the water within the coal cleats (fractures) keeps the methane adsorbed onto the coal.

Does CBM produce "sour gas"?

Unlike conventional natural gas which, typically, must be treated before it enters the pipeline, CBM is considered a "sweet gas," and is generally of pipeline quality. This means there is no hydrogen sulphide (sour gas), which often smells and can be hazardous if released into the air. Sweet natural gas is odourless. The smell commonly associated with the natural gas used in households comes from an additive provided as a safety measure.


No two CBM sites are exactly alike. An area's geological history and the depth of its buried coal determine a coal's type and gas content. Still, conventional natural gas drilling techniques can develop almost any CBM deposit. However, before commercial CBM can be produced, testing is often completed on four or five wells in close proximity.

On the surface, a CBM drilling system looks much like one used in any oil and gas operation. In many cases, it most closely resembles the equipment used to drill water wells.


Coalbed Methane and Conventional Natural Gas: A Comparison

Coalbed methane and conventional natural gas share common production methods and advanced exploration technologies, including drilling equipment, pipelines and compressor systems. However, there are significant differences, a few of which are outlined below.

Well Sites/Pad Sizes

During standard drilling operations, a conventional gas well will affect a surface area measuring 120 by 120 metres (1.44 hectares). Larger areas may be used to accommodate rigs used for directional or deep drilling. Since CBM wells are usually shallower by comparison, smaller rigs and smaller surface areas may be used. Once CBM drilling is complete and the well is connected to the pipeline, the area can be reduced to just large enough for a wellhead and pump, a liquids separator and dehydrator, metering equipment and an optional water tank. Later, some of the area can be re-vegetated and re-contoured, leaving little long-term surface impact.


Typical spacing for U.S. CBM wells is one per 320, 160, or 80 acres. Closer spacing allows the wells to work together to reduce the area pressure, ensures optimum production and increases ultimate gas recovery.

Casing/Drilling

A normal drilling operation for a CBM well involves drilling a hole about 20 centimetres in diameter down to the coal seam. Steel or plastic casing lines portions of the hole. Spaces between the casing and bedrock are filled with cement. This combination of casing and cement prevents the exchange of fluids or gases between the well and surrounding rocks or surficial materials, and ensures that drinking water is protected.


Composition of Gas

Conventional natural gas consists primarily of methane, typically 80-90 per cent. It also contains other hydrocarbons (such as ethane, propane, and butane), as well as other gases (including nitrogen, helium, carbon dioxide and hydrogen sulphide). When hydrogen sulphide, or "sour gas", is present in conventional natural gas the gas must be treated before it enters the pipeline that takes it to your home.

However, CBM is generally a "sweet gas" and of pipeline quality, except in some regions where higher levels of carbon dioxide must be separated and removed. Typically, it consists of more than 95 per cent methane, with small amounts of carbon dioxide and nitrogen. Tests on gases recovered from CBM operations indicate no danger from hydrogen sulphide or any other sulphur components, even with high-sulphur coals. In this respect, CBM is a cleaner, safer, more environmentally friendly fuel than many other energy sources, including conventional natural gas.


Production Lifespan/Well Duration

All natural gas wells vary in the duration of production. Depending on various factors, including size and management techniques, a conventional gas well in Canada can produce for three to 25 years. Current estimates for the average production life of a CBM well vary from ten to as many as 40 years. However, this is impossible to verify as U.S. commercial production has been underway for only about 25 years.

Infrastructure

CBM operations require gas and water-gathering systems. Plastic pipes carry low-pressure gas to a central compressor station where the gas is pumped into an intermediate-pressure steel pipeline. The gas eventually enters a main, high-pressure pipeline where it is carried to market.

Water is collected in storage tanks at the well and transported by truck to a disposal site or moved by pipeline to a suitable central disposal site. Usually, to minimize surface impact, both the gas and water pipelines are buried adjacent to access roads.

Did You Know?
Initially, a CBM well may produce from 50 to over 1,000 barrels of water per day for several months or more. This water may be re-injected into deep aquifers, below potential groundwater zones.


How Will CBM Development Affect Me?
The Environment

Air Quality

Generally, because CBM is nearly pipeline quality upon production, it does not require extensive processing, thereby eliminating a source of potential emissions.

Compressors move the gas from the well to the pipeline system. To minimize the levels of exhaust, CBM-burning engines can be used to drive the compressors. The compressors must undergo frequent testing to ensure they meet strict air-quality standards. In many cases, electrical compressors may be used, further reducing emissions.

Therefore, when CBM can displace other fuel sources such as coal, oil and conventional natural gas, its use will reduce the impacts on air quality.

What Is De-watering ?

De-watering – The process of removing water from a coal seam in the vicinity of a producing gas well. The water in the coal is pumped to the surface and an appropriate disposal method is determined based on water quality and quantity. De-watering is required to reduce pressure within the coal seam which in turn allows the methane gas to be released from the coal.