Integral spiral heavy weight drill pipe is to extend the central upset of heavy weight drill pipe and to cut spiral groove on heavy weight drill pipe.
整体螺旋加重钻杆是在整体加重钻杆的中间加厚部位延长并铣削螺旋槽。
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It acts as the LPF, effectively eliminating the high frequency component in the feed-in signal. The groove in the central region working as a loading capacitance in the open end is also discussed.