DRILL PIPE Russian patent published in 1994 - IPC

FIELD: drilling of prospecting and producing oil and gas wells; equipment for drilling ultradeep wells. SUBSTANCE: drill pipe has body with tool joints and annular floating member located in body space and enclosed in sealed containers made of heat-pressure-resistant plastic material of low density (duralumin, alor, etc). Inner wall of container may have corrosion-resistant coating up to 0.1-1.0 mm applied by spraying. Sealed containers prevent floating members from destruction and loss of their properties when pipe is found in corrosive well medium with high temperature and pressure. Corrosion-resistant coating reduced also the hydraulic resistance factor. EFFECT: higher efficiency. 2 cl, 5 dwg