METHOD FOR REMOVING SEDIMENTATIONS FROM INJECTION WELLS Russian patent published in 1997 - IPC

FIELD: oil and gas production industry. SUBSTANCE: method allows for restoration of injectability of well close to initial value in off-shore sea deposits. According to method, injected into perforated bottom-hole zone of reservoir is solution containing sodium or potassium salts of sulphuroxygen-containing acids, fluorohydrogen acid and surface-active agent. In preparation of solution, used as sodium salts of sulphuroxygen-containing acids are potassium pyrosulphate and potassium bisulfate , and used as potassium salt of sulphuroxygen-containing acid is potassium pyrisulphate. Solution time delay for reaction is determined depending on reservoir temperature: 1-2 h at temperature of 120-140 C, 2-4 h at 90-120 C, 4-6 h at 60-90 C. EFFECT: high efficiency. 3 cl, 3 tbl