METHOD FOR COLLECTING AND PREPARING DRAINAGE WATER Russian patent published in 2007 - IPC E21B43/34 B01D17/04 

FIELD: oil industry, possible use for preparing oil emulsion at oil preparation plants.

SUBSTANCE: method includes feeding oil emulsion received from oil fields into devices for preliminary water disposal, separating water part from oil emulsion in preliminary water disposal devices and draining of water part to cleaning structures, cold separation of gas from oil emulsion in buffer vessels, heating of oil emulsion in heat exchangers and in furnace, hot dehydration of oil emulsion at hot sediment stages, desalination of oil emulsion in electric dehydrators with feeding of fresh water into electric dehydrators through disperser, feeding of drainage water after hot sediment and electric dehydrators to beginning of process at devices for preliminary water disposal, feeding of processed oil from electric dehydrators through heat exchangers into buffer vessels for processed oil, hot separation of gas in buffer vessels for processed oil and feeding of oil to consumer. In accordance to invention devices for preliminary oil disposal are divided on two steps. First step is operated in normal mode with feeding of oil emulsion from oil fields into inlet and from preliminary water disposal devices into buffer vessels. Second step is bound in parallel to first step, feeding of oil emulsion from oil fields into inlet of second step of preliminary water disposal devices is prevented. Drainage water after hot sediment and electric dehydrators is fed to inlet of second step of preliminary water disposal devices, without mixing thereof with water-oil emulsion received from fields. From second step of preliminary water disposal devices part of water is fed into cleaning structures and oil emulsion is fed into inlet of buffer vessels. Influx of drainage water into inlet of second step of preliminary water disposal devices is performed through lower manifold-distributor of device below layer of water cushion, while technological process in second step of preliminary water disposal devices is performed at temperature of 50-80°C.

EFFECT: increased efficiency of separation of water-oil emulsion at preliminary dehydration stage onto oil and water, stabilization of hot dehydration stages operation, desalination of oil and prevention of growth of number of intermediate layers from stable emulsions.

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