Energy

The extraction

Often, albeit not always, natural gas is extracted from the same fields as oil. Just like oil, natural gas is the result of the transformation of organic substances deposited at the bottom of ancient seas and lakes (sedimentary basins). Therefore, there is no search for natural gas distinct from that of oil, but a single research activity for hydrocarbons: only after exploration wells are drilled is it possible to ascertain the nature of the deposit. The term “associated gas” is used when natural gas is dissolved into oil or makes up the top layer of the oil field; the expression “non-associated gas” is used when the field contains almost exclusively natural gas (for example, the large field of the North Sea or the Netherlands). Extracting natural gas from underground is quite easy. Usually it is trapped together with oil under a rock layer. Due to the big pressure, as soon as drilling is finished, the gas comes out and it is necessary to “direct” it into a pipe and guide it towards its final destinations or storage centres. The latter are not tanks like the ones containing oil, but they are exhausted natural reserves that once contained natural gas, oil or water and that are used today as real “warehouses” for the gas.