DRILL PIPE (VARIANTS) Russian patent published in 2005 - IPC

FIELD: drilling equipment, particularly adapted to use in bottomhole assembly to reduce deviation of holes bored in anizotropic rock.

SUBSTANCE: drill pipe comprises metal body having ring-shaped cross-section with two diametrically remote segments forming flat longitudinal areas on pipe surface. Drill pipe also has connection threads located at body ends. In the first embodiment outer layers of flat longitudinal areas are formed of metal having higher coefficient of elasticity than that of metal used for remainder pipe body forming due to plastic deforming thereof. In the second embodiment outer layers of flat longitudinal areas are coated with metal having higher coefficient of elasticity in comparison with that of basic metal. In the most preferable embodiment metal layer is applied on plastically deformed metal of flat longitudinal areas to provide unequal rigidity along main axes of pipe cross-section.

EFFECT: increased efficiency and improved operational performance.

3 cl, 4 dwg, 1 ex