Glossaire :Active solar system [...] Atom

Active solar system (see the French definition ): A means of capturing, storing and distributing solar energy that requires an external energy source to work.
Additive (see the French definition ): Chemical compound added to a fuel base or lubricant to improve its properties.
Aerobic (see the French definition ): Describes a microorganism whose life depends on the presence of free oxygen which is contained in the air.
Alkylation (see the French definition ): Alkylation is one of the main petrochemical reactions. It is used to increase the number of carbon atoms in an organic compound (a substance containing at least one atom of carbon and one atom of hydrogen). In petroleum product refining it is particularly used to produce fuels such as unleaded gasoline 95 and 98.
Anaerobic (see the French definition ): Describes a microorganism that can live without free oxygen.
Anaerobic bacterium (see the French definition ): A bacterium which can survive without oxygen.
Anaerobic fermentation (methanization) (see the French definition ): Fermentation in the absence of oxygen.
ANDRA (see the French definition ): French National Radioactive Waste Management Agency [Agence Nationale pour la Gestion des Déchets Radioactifs]. ANDRA is an industrial and commercial public body that is responsible for the long-term management of radioactive waste produced in France.
Anthracite (see the French definition ): A type of coal with 95% pure carbon content. An excellent fuel.
Anticline (see the French definition ): A swell or fold of the ground that is convex up. Anticlines are one of the main types of hydrocarbon trap.
Anticyclone (see the French definition ): The center of high atmospheric pressure which can keep atmospheric disturbances away.
Appraisal drilling (see the French definition ): Also called delineation drilling, appraisal drilling is carried out to gain a better understanding of the structure and extent of a deposit in order to decide whether to mine it or not. It is used in tandem with exploration drilling.
Aquifer (see the French definition ): An aquifer is a geological formation which acts as a natural reservoir. It can store water and let it flow through easily, thereby making it an ideal location for groundwater.
Arch dam (see the French definition ): A type of dam in the shape of a convex arch supported by the lateral rock walls which help the dam to withstand the pressure of the water that it retains.
Artificial fracturing (see the French definition ): When engineers want to increase the oil or gas extraction flow from reservoirs with poor permeability, they can use the technique of artificial fracturing. By injecting water at high pressure, fissures and fractures are made in the reservoir rock. The hydrocarbons will then be able to flow more easily through these fissures. Hydrochloric acid can also be injected to dissolve carbonates, while hydrofluoric acid can also be used as it dissolves silica (acidification). This can artificially increase permeability. The two methods can even be used in tandem (acid fracturing).
Artificial radioactivity (see the French definition ): Artificial radioactivity comes from man-made radioactive elements that are required for energy production, medical purposes and industrial uses.
Assisted recovery (see the French definition ): When an oil or gas deposit starts to be worked, a pressure lower than the reservoir pressure is applied in the production well. Under this different pressure, both oil and gas will travel towards the well and naturally rise. After some time, the pressure in the deposit will drop and the oil and gas flows will fall. Production therefore has to be stimulated by assisted recovery techniques if production is to be kept at the required rate. There are two main assisted recovery techniques, which are pumping and water or gas injection.
Atom (see the French definition ): The basic unit of matter that comprises a nucleus which is surrounded by a cloud of electrons.