METHOD OF PURIFICATION OF ACCOMPANYING WATERS OF OIL-GAS FIELDS Russian patent published in 2008 - IPC C02F1/463 C02F103/10 

FIELD: chemistry.

SUBSTANCE: invention relates to complex purification of accompanying waters of oil-gas fields and can be used at enterprises of oil-gas complex. To implement the said method alkali solution is introduced into purified water for creation of alkaline medium. pH 8.5-12.5. In obtained alkaline solution steel electrodes are submerged. Constant voltage ensuring creation of oxidative-reduction potential Eh(-50)÷(-120) mV and disperse phase coagulation is applied to the electrodes during a time period sufficient for sorption by disperse phase of cations and anions of radioactive nuclides. Then electrodes are de-energised. Sedimentation of disperse phase, separation of sedimented disperse phase and neutralisation of purified solution are carried out. To create the aforesaid oxidative-reduction potential applied to the electrodes constant voltage is chosen equal to 6-12 V with current strength of 3-900 A. The method ensures purification of accompanying waters from natural radioactive nuclides and simultaneously from phenols and surface-active substances used in technological cycles of oil and gas production. In addition, the method allows reducing mineralisation and carbonate hardness of accompanying waters, concentration of total iron and suspended substances.

EFFECT: purification of accompanying waters of oil-gas fields from natural radioactive nuclides, phenols and surface-active substances; reduction of mineralisation, carbonate hardness, concentration of total iron and suspended substances in water

2 cl, 1 ex, 5 tbl