SEALING OF PIPE AND STRING CLEARANCE Russian patent published in 2004 - IPC

FIELD: oil and gas production. SUBSTANCE: invention deals with sealing of pipe and string clearance, especially in wells with abnormally high pressure. In compliance with invention well is killed with process fluid. String is perforated. Chaser and grouting mortar are injected. Excess of grouting mortar is forced out of well. Well is abandoned in waiting on solidification of grouting mortar. Process fluid is driven with service water under excessive pressure on formation. Then string is perforated in upper part of permeable horizon and bottom of bridge lying above. Well is blasted for flame under maximum depression, is flushed with service water under excessive pressure with regard to pressure in formation and water-soluble polymer coagulating and solidifying with contact with stratal water containing ions of polyvalent metals is pumped in. Grouting mortar is injected and driven into formation, pipe and hole clearance with preservation of excessive pressure. Mixture of cement with rheological reinforcing and especially finely divided mineral binding additive of MICRODUR type is utilized in the capacity of grouting mortar. EFFECT: prevented filtration of fluid in pipe and hole clearance, expanded functional potential of approach.