Patent ID: 8353497
Filing Date: 2013-01-15
Classification: E21B

Abstract:
1. A packing unit to seal a wellbore, the packing unit comprising: at least one rotatable cam disposed about an axis of the wellbore, the at least one rotatable cam having a cam axis and being rotatable about the cam axis, the axis of the wellbore being generally perpendicular to a horizontal plane defined by the cam axis such that rotation of the at least one rotatable cam about the cam axis moves the at least one rotatable cam toward the wellbore and relative to the horizontal plane; and the at least one rotatable cam comprising an outer peripheral surface that includes first surface portion and a second surface portion that is adjacent to the first surface portion, a seal recess defined by the first surface portion and the second surface portion; wherein the seal recess comprises a taper between at least a first rotary position and a second rotary position, the taper configured to seal against a range of radii between a minimum radius and a maximum radius as the at least one rotatable cam is rotated about the cam axis between the first rotary position and second rotary position: and wherein the packing unit sealingly engages a tool in the wellbore by rotation of the at least one rotatable cam, bringing the seal recess into sealing contact with the tool.