How does coal seam gas form?
How does coal seam gas form?
Gases in coal seams are formed during the long geological process of coal formation (coalification) when organic matter is converted into coal. The gas accumulates underground, held within the cleats (natural fractures) and pores of the coal itself. Not all coal seams contain useful quantities of methane.
How is CSG extracted?
Coal seam gas is extracted by drilling a well vertically through rock strata until reaching the coal seam, at which point the well may also be drilled out horizontally to increase access to the methane gas. Coal seams contain both water and gas.
Why is coal seam gas so controversial?
Possible environmental effects: environmental groups have raised concerns that CSG development might cause environmental damage through release of untreated production water at the surface; damage to, and contamination of underground aquifers by hydraulic fracturing; damage to wildlife habitat in sensitive areas and …
How do you find a coal seam?
A coal seam is a dark brown or black banded deposit of coal that is visible within layers of rock. These seams are located underground and can be mined using either deep mining or strip mining techniques depending on their proximity to the surface.
How do you make coal gas?
Coal gas is produced when coal is heated in the absence of air in an enclosed chamber. When bituminous coal is heated to a temperature of about 400°C it softens and coalesces, giving off water vapour, rich gas and tar.
What is mining and fracking for coal seam gas?
In some cases hydraulic fracturing, or ‘fracking’, is used to extract coal seam gas. Hydraulic fracturing is the process of injecting fluid under high pressure into a coal seam to widen existing fractures and create new ones.
How is crude oil formed?
Crude oil is formed from the remains of dead organisms (diatoms) such as algae and zooplankton that existed millions of years ago in a marine environment. As they lived these organisms absorbed energy from the sun and stored it as carbon molecules within their bodies.
Is coal seam gas renewable?
Coal seam gas is a non-renewable energy resource that is a by-product of coal. The methane gas is contained within the coal seams by water from groundwater aquifers.
Is coal seam gas good or bad?
Some chemicals used in drilling and hydraulic fracturing, and naturally occurring contaminants released from the coal seam during mining, could harm human health, given sufficient dose and duration of exposure. This potential harm includes increased risk of cancer.
What is a coal seam?
Definition of coal seam : a bed of coal usually thick enough to be profitably mined.
What is coal seam gas and how is it made?
What is coal seam gas? Coal seam gas (CSG), also known as coal bed methane, is a form of natural gas typically extracted from coal seams at depths of 300-1,000 metres. CSG is a mixture of a number of gases, but is mostly made up of methane (generally 95-97 per cent pure methane).
How do you extract methane from coal seams?
In deeper and low permeability coal seams, hydraulic fractures are used to extract methane from coal. This involves pumping a mixture of water, sand, and other additives at high pressure down the well and into the coal seam, fracturing the coal seam and providing a track for gas to flow back.
What are the reservoir properties of a coal seam?
Coal seams are both a source and the reservoir for all gases in them. For a successful drainage of methane from coal, the reservoir properties of coal seams must be determined. These include the gas content, permeability, sorption time, and the reservoir gas pressure.
What is CO2 CSG gas?
Coal seam gas (CSG), also known as coal bed methane, is a form of natural gas typically extracted from coal seams at depths of 300-1,000 metres. CSG is a mixture of a number of gases, but is mostly made up of methane (generally 95-97 per cent pure methane). It is typically attached by adsorption to the coal matrix,…
