METHOD OF DESALTING AND DEHYDRATING HEAVY VISCOUS CRUDE OIL AND TRAPPED PETROLEUM PRODUCT

FIELD: crude oil treatment and petroleum processing. ^ SUBSTANCE: method comprises dilution of heavy viscous crude oil or trapped petroleum product with light-weight low-viscosity petroleum at ratio of 30 to 70% on the weight of feedstock or mixing with either gasoline recovered from heavy viscous crude oil or gasoline from thermal processes of petroleum processing, or trapped gasoline formed in trimming water/gasoline emulsion from commercial gasoline tanks followed by settling of water, said gasoline being used in amount 5 to 50% on the weight of feedstock. Desalting i9s performed in three stages, wherein, in the first stage, thermal settlers and, in subsequent stages, electrodehydrators are employed. Before each stage, demulsifier such as mixture of polyalkylene glycols is added to oil in following amounts: before feedstock pump 20-100 g/t and before each subsequent desalting stage 3-15 g/t. Advantageously, in order to enhance efficiency of mixing wash water with oil, mechanical facilities such as sprayers or perforated barriers are employed. ^ EFFECT: enhanced desalting and dehydration efficiency and reduced power consumption. ^ 4 cl, 7 tbl, 5 ex