ELASTIC CENTRALIZER Russian patent published in 1997 - IPC

FIELD: drilling equipment; applicable in bottomhole assembly of drill string in drilling of oil and gas wells. SUBSTANCE: centralizer has stem, frame installed on stem with the help of radial supports and distance bushing. Frame has arched supporting strips. To limit sagging of the latter, supports are used which are made in form of rings located between end faces of radial supports and distance bushing, or in form of circular protrusions of distance bushing. Stops may be located on internal surface of supporting strips and may be removable. When drilling tool is run into well, supporting strips undergo deformation along entire length, therefore, their rigidity for bending is rather small. In drilling of curved wellbore, only central part of supporting strips undergo deformation between supports that leads to sharp rise of their bending rigidity. As a result, flexible centralizer is capable of holding the bit axis in the center of wellbore in complicated drilling conditions. EFFECT: higher efficiency. 5 dwg