WELL COMPLETION METHOD Russian patent published in 2020 - IPC E21B21/00 E21B7/00 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry, namely, to drilling, flushing, cleaning and construction. When implementing the method after drilling to the design depth, but before lowering the cementing assembly, the drill string is lifted above potential areas of complications or into the shoe of the previous casing string. Performing process exposure at exceeding of drill string rise time above potential intervals of complications exceeding time of sedimentation of drill cuttings and sludge remaining in the borehole. For patterning, drill string is repeatedly lowered to bottomhole with circulation of fluid with flushing and pacing of drilling tool landing points till weight recovery with fixation of intervals of plantings by depth and interval. When the project face is reached, the well is flushed for removal from the well bore to the surface of the drilled cuttings and the slopping mud. Lifting of the drilling assembly is performed with drilling fluid topping to exclude oil and gas manifestation at the well head. Geophysical survey of the well is performed. Casing string is equipped from below with a shoe to assemble the cementing assembly before lowering. Downhole of cementing layout is drilled to drilled borehole with periodic flushing of the well. When guiding the assembly along the shaft, the weight of the assembly is constantly determined on the lifter, with reduction of weight, the well is flushed with simultaneous reciprocation of the arrangement before weight returns. At that, flushing liquid rate and flow rate is increased at passage of fixed intervals for removal of rock and slime from shedding zones.

EFFECT: avoiding emergency situations during drilling, casing stringing and lowering due to fixation of drilling tools depth and intervals during patterning and passage of these sections with increased speed and supply of flushing fluid till recovery of weight of cementing assembly.

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