CEMENTING METHOD FOR HORIZONTAL SHAFT OF WELL Russian patent published in 2015 - IPC E21B33/13 

FIELD: oil and gas industry.

SUBSTANCE: cementing method for a horizontal shaft of a well lies in running in to the drilled shaft of the well of a cementing assembly consisting of a casing shoe, a filter, a tube with plugs and a casing string. At running-in of the assembly the well is washed through 350-450 m, then periodical washing through 250-350 m is executed. Before entry to the horizontal shaft, while passing the assembly through the horizontal shaft, its weight is determined on the permanent basis at the elevator. When the weight is reduced per 2-3 t the well is washed with simultaneous reciprocating of the assembly per 8-10 m till the weight is returned; thus the whole interval of the horizontal shaft is passed up to the bottom. When the assembly is thrust to the bottom an additional washing cycle is performed with reciprocating. The assembly is thrust to the bottomhole. Packing cement is injected and squeezed through the tube with the plugs to the borehole annulus thus opening the plugs of the tube by the squeeze pressure.

EFFECT: easier delivery of the casing string to the horizontal shaft of the well.