METHOD OF PREPARATION OF PLUGGING BRINES FROM NATURAL MINERALIZED WATERS AND PLANT FOR ITS EMBODIMENT Russian patent published in 2000 - IPC

FIELD: oil producing industry. SUBSTANCE: method is based on concentration of natural waters whose main component is sodium chloride by electrodialysis with production of dialyzate and concentrated brines. Electrodialysis is carried out by galvanostatic method with current density of 150-200 A/sq. m to brine density of 1100-1110 kg/cu.m. Dialyzate flow with salt content of 4.0- 4.5 kg/cu. m is divided into two flows with quantitative ratio governed by content of carbonate and bicarbonate ions in composition of initial mineralized water. Flow smaller in volume is directed to three-route electrodialyzer where conversion of sodium chloride is conducted to produce acid and alkali solutions. Alkali solution is supplied to stage of water treatment including degassing and aeration of water. Acid solution flow is mixed with mineralized flow before its galvanostatic electrodialysis. Brine obtained after electrodialysis is subjected to evaporation to produce saturated brine used in preparation of heavy plugging solutions. Salt solutions are evaporated due to utilization of heat produced by combustion of associated gas in direct contact with brine in foam layer. In course of degassing, at stage of water preparation gas phase in form of, mainly, methane is separated from water and used as fuel for preparation of heat carrier. During aeration of senomanian water, it is purified from iron and also from organic impurities when underlying water is used, which is produced together with oil production. Plant includes casing string, pump for transfer of mineralized water, device for brine production with high concentration of salts and based on electrodialysis apparatus, vessels for accumulation of concentrated salt solution and dialyzate, device for production of acid and alkali solutions and vessels for their accumulation, evaporator for production of saturated brine, desalting device for further potentiostatic demineralization of dialyzate obtained in galvanostatic electrodialysis of initial water. Provided also are degasser-settler, aerator-flotator and filter for separation of iron hydroxide and solid suspended matter, and slime accumulator. All apparatus are interconnected with pipelines and valves and provided with pumps for transfer of process solutions and brine. Filter included in plant equipment is in form of metal case accommodating collector and vertical cylindrical filter element. EFFECT: provided production of plugging brines with maximum salt concentration from natural mineralized waters and with minimum power consumption. 7 cl, 7 dwg, 5 tbl, 8 ex