INTERNAL PIPE CATCHER Russian patent published in 2002 - IPC

FIELD: oil and gas industry, grabbing, holding and lifting of pipes left in well as result of breakdown. SUBSTANCE: internal pipe catcher has housing with male screw surface. Upper part of housing is joined to adapter and its lower part is connected to nipple. Pipe catcher has grabbing unit with female screw surface matching male screw surface of housing and limiting unit. The latter comes in the form of bushing located in upper part of nipple. Lower part of grabbing unit has conical guide and cylindrical surface. Cylindrical surface enters bushing for axial movement with reference to housing, length of cylindrical surface corresponds to value of free travel of grabbing unit in axial direction. Proposed approach makes it feasible to increase reliability of operation by prevention of damage to grabbing unit in process of entry of unit into broken pipe thanks to reduction of radial force of grabbing unit and broken pipe and thanks to fixation of axial movement of grabbing bushing with use of conical guide and cylindrical surface located in limiting bushing. EFFECT: increased reliability of operation of internal pipe catcher. 1 dwg