| 摘要 |
A rotating drill string sub redistributes wellbore drill cuttings into the drilling fluid flowstream to improve the efficiency of the drilling operation. Standoff elements are located on each side of an agitator, all configured on a relatively short section of drill pipe. The agitator comprises a plurality of alternating blades standing radially outward from and arranged helically about the axis of the sub, and grooves located between pairs of adjacent blades, each groove comprising a flow channel that is open at both ends of the agitator. The standoff elements contain abutment surfaces having an outer diameter greater than the outer diameter of the agitator, so that the agitator is prevented from contacting the wall of the wellbore and therefore does not experience the forces that the standoff elements experience.
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