Exploring for gas

Looking for natural gas is similar to prospecting for oil (and usually the two fuels are found together). A team of experts – geologists, geochemists, drilling engineers and geophysicists – work together to discover oil and gas.

Geologists and geophysicists collect information about the structure of the earth's crust to determine the presence of 'traps' or reservoirs that may contain oil and gas. This information comes from magnetic measurements, gravity measurements, detection of oil and gas escapes, and seismic surveys. Satellites, aeroplanes, ships and land vehicles are used to collect this information. Seismic surveys generally use echoes from a vibration source at the earth's surface to collect information about the rocks beneath.

Whatever measurements are made, the presence of gas can only be confirmed by drilling a well. Drilling a well is expensive and generally only one in five wells successfully locate gas or oil. Many more wells may be required to determine the size of the trap and the amount of oil and gas it contains. Only then can a decision be made to develop the oil or gas find for commercial production.

Commercial production requires the construction of production and processing plants, and pipelines to deliver the gas to market. If the find is located under the sea, it may be necessary to construct a platform for production equipment. The production platform may rest on the sea floor or, if the water is very deep, may float above the wells.