TUBULAR MEMBER EXPANDER Russian patent published in 2006 - IPC E21B7/20 E21B29/00 

FIELD: simultaneous drilling and casing wells, particularly expanders adapted to widen tubular member in radial direction.

SUBSTANCE: expander comprises body adapted to be connected to elongated member, which moves the expander in axial direction via tubular member. The expander includes the first body part and the second body part offset from the first body part in axial direction. The first body part has larger outer diameter in comparison with the second body part. Expanding member set is arranged around expander body. Each expanding member may be offset with respect to expander body between the first position, in which expanding member is retracted in radial direction and is leveled in axial direction with respect to the second body part. Expander has cooperating device adapted to provide displacement of each expanding member between extended position and retracted position. In accordance with the first embodiment each expanding member and the first body part are provided with cooperating support profiles to prevent reaming member displacement in axial direction with respect to the first body part during tubular member expansion, which results in expanding member holding in its expanded position. In accordance with the second embodiment expanding members installed in their extended positions create substantially solid conical surface, wherein each two neighboring expanding members have common interface extending along cone surface at an angle to radial plane including longitudinal expander axis.

EFFECT: increased efficiency.

10 cl, 6 dwg