Abstract: A mandrel arrangement is for use in a wellbore tubing. A method is for using the same. A mandrel body houses at least one piston, the at least one piston being movable in relation to the mandrel body between a first position and a second position by a fluid force acting on the piston. A cavity is arranged adjacent the piston for communicating wellbore fluid pressure between the wellbore tubing and the piston. The cavity is provided with drainage means for facilitating removal of any particles present in at least a lower portion of the cavity.
Abstract: A well barrier is for sealing off a first portion of a wellbore from a second portion of the wellbore, the first portion having a higher fluid pressure than the second portion. The well barrier is held in place in the wellbore by a holding means. The well barrier is preshaped to disintegrate in at least three barrier elements upon activation of a disintegration means, at least one of the barrier elements having a surface area facing the first portion of the wellbore that is larger than the surface area facing the second portion of the wellbore. A method is for controlling a disintegration of the well barrier.