METHOD FOR WELL CONSTRUCTION Russian patent published in 2012 - IPC E21B7/00 E21B21/00 

FIELD: construction.

SUBSTANCE: method for well construction includes rotation and axial feed of a layout with a chisel and supply of a drilling mud via an inner cavity of the layout for landing, lowering and cementing of a casing string. Drilling is carried out with application of a hydraulic downhole motor, when a zenith angle of more than 25° is reached, and there is a risk of drill string sticking prior to the drill string build-up, a pack of the drilling mud base is squeezed into a bottomhole area with zero content of a weighting agent and a solid phase with density of 1000-1010 kg/m³ in the volume of 8-12 m³, the annular space is sealed, and 0.5-1 m³ of the drilling mud base pack is squeezed into the bottomhole area with the wellhead pressure of not more than 3 MPa and the flow from 10 to 16 l/s, soaked for not more than 1 minute, the pressure is released, and the drill string is built up, circulation of the drilling mud is recovered, drilling continues with the drilling mud, during the subsequent building-up of the drill string the operations are repeated.

EFFECT: invention provides for drilling of wells with a high zenith angle without sticking of a drill string during its build-up.

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