SHALE GAS

SHALE GAS: shale gas refers to natural gas that is trapped within shale formations. Shales are fine-grained sedimentary rocks that can be rich sources of petroleum and natural gas. Shale is one of the Earth’s most common sedimentary rocks. It is a fine-grain rock composed mainly of clay flakes and tiny fragments of other minerals. Shale can be a gas reservoir, but only formations with certain characteristics are viable for development. Over the past decade, the combination of horizontal drilling and hydraulic fracturing has allowed access to large volumes of shale gas that were previously uneconomical to produce. The production of natural gas from shale formations has rejuvenated the natural gas industry in the United States. Thermogenic (from the Greek word meaning ‘formed by heat’) gas forms when organic matter in shale is broken down at high temperatures, often a result of burial deep underground. The gas is then reabsorbed by organic material to trap the gas within the shale. Shale gas is the most commonly known unconventional gas.