What is Shale Gas?

Shale gas (or gas shale) refers to natural gas (mainly methane) found in fine-grained, organic-rich rocks.

When talking about shale gas, the word shale does not refer to a specific type of rock. Instead, it describes rocks with more fine-grained particles (smaller than sand) than coarse-grained particles, such as

• shale (fissile) and mudstone (non-fissile)
• siltstone
• fine-grained sandstone interlaminated with shale or mudstone
• siliceous and carbonate rocks.

Gas-prone shale may be associated with other resources, such as tight gas and coalbed methane (CBM) in areas where shale is interbedded with coal.