Natural gas: the facts

What is shale gas and tight gas?

Shale gas is natural gas that is trapped within shale formations of rock. The rock is impermeable, meaning liquids cannot pass through, which makes it harder to extract. Tight gas is held in rock pores 20,000 times narrower than a human hair. A special technique, known as hydraulic fracturing, is needed to extract it.

What is fracking?

A technique known as hydraulic fracturing or fracking is used to break open rock and release natural gas. This involves pumping fluids into the well at high pressure. The fluids are made up of around 99% sand and water, with 1% chemicals added to help the gas flow more freely. Hydraulic fracturing typically takes place a kilometre or more (thousands of feet) below drinking water supplies. Concrete and steel barriers are inserted into the wells to prevent any drilling or fracturing fluids from entering local water supplies.

How is natural gas transported?

Natural gas can be transported by pipeline or ship to where it is needed. By using pipes, gas can be cost effectively transported over long distances as part of an integrated gas transport network. If lined up together, the total length of the world’s natural gas pipelines would stretch to the moon and back eight times. When pipelines cannot cost-effectively reach consumers, natural gas can be cooled to make a liquid, shrinking its volume for shipping to where it is needed.

Is natural gas safe?

Natural gas is naturally colorless, odorless and tasteless. Some countries require an odor to be added to gas so that, in the unlikely event of a release, the gas can be detected. Pipeline companies take steps to ensure that health, safety, security and environmental concerns are addressed throughout the planning, construction, and operational phases of pipeline operations. They work to prevent releases of gas by evaluating, inspecting and maintaining pipelines.

When gas is cooled for shipment over longer distances, it turns into a clear, colourless and non-toxic liquid. In its liquid state, liquefied natural gas (LNG) is not explosive and cannot burn. LNG tankers are specially designed with double hulls to protect the cargo systems from damage or leaks.

What is the environmental impact of natural gas?

Natural gas is the cleanest-burning hydrocarbon. Natural gas emits between 45% and 55% lower greenhouse gas emissions than coal when used to generate electricity, according to IEA data.  Compared to coal-fired power plants, modern natural gas-fired power plants emit less than one-tenth of the pollutants.

Is methane harmful to the environment?

Methane is a potent greenhouse gas. When it is released into the atmosphere it has a much higher global warming impact than CO₂. Natural gas consists mainly of methane. Efforts to address climate change therefore require the industry to reduce both deliberate and unintended methane emissions from production to the final consumer. It is important that the gas industry continues to monitor and reduce methane emissions. This includes wider implementation of leak detection and repair programmes which use infrared cameras.