In most oil terminals there is no processing or other product transformation on site. The products from a refinery which are stored in the terminal are in their final form suitable for delivery to customers. Blending of products may be undertaken, and additives may be injected into products, but there is usually no manufacturing plant on site. Modern terminals have a high degree of site automation.

Some oil terminals receive crude oil production from offshore installations. Crude oil received by pipeline may have been ‘spiked’ with natural gas liquids (NGL), and is known as live crude. Such oil needs to be processed or stabilised to remove the lighter fractions such as ethane, propane and butane to produce a dead or stabilised crude that is suitable for storage and transport. Such oil terminals may include processing facilities to treat the oil to achieve an oil Reid vapor pressure (RVP) of 10 to 12 psi (70 to 82 kPa). The process facilities include oil heaters to warm the oil which then routed to separator vessels. In the separators the lighter fractions flash off from the oil and are further processed to separate them into their individual components. The now stabilised oil can be routed to storage and then sold or sent for further processing.

The storage tanks at an oil terminal may includes fixed roof tanks, internal floating roof tanks and external floating roof tanks. Floating roof tanks are generally used for more volatile products to reduce evaporation loss. Fixed roof tanks which have a vapor space above the product and which breathes in or out as the product is removed or the tank is filled. Some tank may be fitted with internal heating coils using hot water or steam to keep the contents warm. This reduces the viscosity of the product to ease transfer and pumping. Terminals may also have ‘Horton spheres’ which are used to store liquefied petroleum gases such as propane and butane (see left foreground of the above Kowloon oil depot).