DOWNHOLE HOLE CLEANING JOINTS AND METHOD OF USING SAME Russian patent published in 2019 - IPC E21B37/00 E21B17/22 

FIELD: drilling soil or rock.

SUBSTANCE: group of inventions relates to tubular articles, for example, components of a drill string and drill stem, used in downhole operations. Hole cleaning joint for a drill string, which descends into the wellbore, comprises a tubular body connectable to the drill string and a hole cleaning section positioned about the tubular body. Hole cleaning section has an outer surface engageable with a wall of the wellbore. Outer surface has spiral grooves extending therein defining blades therebetween. Each spiral groove has a location of maximum width and maximum depth, wherein each spiral groove forms a spiral recess between the end of the wellhead and the end of the well bottom. Each spiral groove has a width and depth that decreases from the location of the maximum width and depth towards the end from the wellhead and the end from the well bottom, respectively. Each end of each spiral groove ends at the point of curvature. Each spiral recess forms a tapering flow channel for receiving drill cuttings passing through it to effect movement of drill cuttings to the wellhead during drilling.

EFFECT: optimisation of hole cleaning, acceleration of movement of drill cuttings and improvement of dispersion of drill cuttings.

37 cl, 23 dwg