DRILL PIPE WITH GAS LINING Russian patent published in 2000 - IPC

FIELD: drilling of prospecting, producing oil, gas and special wells with scientific purposes and also mine shafts; completing of drilling tools. SUBSTANCE: drill pipe includes carrying pipe body with joints. Internal surface of pipe body has coating in the form of circular floating member with density less than that of fluid filling the well. Floating member of lined pipe is made in the form of single integral insert or several sectional circular inserts each in the form of spiral coiled within insert dimensions, heat-pressure resistant long tubular vessel of minor diameter filled with light gas (for instance, helium) at initial pressure ensuring compensation of crushing external pressure equalling the sum of hydrostatic and hydrodynamic pressures at depth of pipe lining in well. EFFECT: higher operating reliability of drill pipe in prolonged contact with corrosive high-temperature well hydraulic medium, and reduced cost of lined pipe. 2 cl, 4 dwg