摘要 |
According to the invention a flexible drill pipe constructed of a closed pitch cylindrical spiral coil of wire rod with a floating core of tube sections constructed the same positioned end to end but not attached through the hollow center of the coil of wire rod to keep the coil of wire rod from collapsing under torsion loads required for a drilling operation. A thin wall hose is laid through the tube sections so drilling fluids can be pumped through the flexible drill pipe during a drilling operation.
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