SEALING METHOD OF CONNECTION OF MAIN AND SUPPLEMENTARY BORE HOLES Russian patent published in 2012 - IPC E21B43/10 E21B33/10 

FIELD: oil and gas production.

SUBSTANCE: sealing method of connection of main and supplementary bore holes consists in drilling of main bore, descending of main casing string, spudding of supplementary bore from the main one, descending of additional casing string with sealing connection with main casing string, cementing of additional and main casing strings. Connection sealing is done after cementing of additional casing string and plant in its upper part and in the main casing string below spudding interval of supplementary bore of cutting packers, note that connection sealing is performed by pumping of fixing agent above spudding interval of supplementary bore from the main above the cutting packers, after process holding enough for fixing and sealing of open bore walls in the connection there performed is a wash-out of excessive fixing agent and dismounting or drilling out of cutting packers.

EFFECT: application of the proposed method due to its simplicity, exclusion of necessity to manufacture non-standard equipment and low cost allows reducing expenses on connection sealing of main and supplementary bore holes.