Raw Materials

The raw materials processed by the refinery are crude oil and partially processed fuels. All these materials are delivered to Coryton by ship. The deep water channel of the Thames Estuary allows tankers carrying up to 100,000 tonnes of oil to dock at Coryton. Coryton has five jetties (see fig. 10). The most easterly jetty extends out furthest into the deep water channel and is used for the unloading of very large crude carriers (VLCCs), usually from the Middle East or North Africa.

Each day 33 million litres of crude oil are delivered. Most of the oil used at Coryton is from the North Sea (see Figure 9) and is delivered in smaller tankers. The location of North Sea oil fields is shown in Figure 2 on page 2. The jetties are also used for the loading of refined products leaving the refinery.

Unloading

Figure 11 shows a tanker being unloaded. The oil is taken by pipeline to storage tanks before being fed into the refining process. However, it spends very little time in storage, at most a few hours.

Coryton has a total of 220 storage tanks. The largest (in the foreground of Figure 11) hold 80,000 tonnes. The movement of crude oil is carried out in a ‘closed system’. This means that there is no loss of oil or gas to the atmosphere.

In Figure 11 it can be seen that the tops of the crude oil storage tanks are floating. This is for safety reasons so that no gases build up beneath the roof or escape to the atmosphere.

Shipping Movements

In the month of October 1999 58 ships and 20 motorised barges docked at the Coryton jetties. The table below gives information on the ships docked at Coryton on one high tide on one day in October 1999.