| 摘要 |
A spearing device for use in removing casing is disclosed. The spearing device includes: a top sub; a bottom sub; a mandrel, coupled to the top and bottom subs, having an outer corrugated surface; a grapple having a correspondingly corrugated inner surface and an outer surface including wickers for engaging an interior surface of the casing; a piston disposed within the mandrel and operatively coupled to the grapple; and a spring operative with the piston and biasing the grapple toward a collapsed position. The grapple: (i) axially and rotationally moves along the corrugated outer surface of the mandrel and (ii) expands and collapses responsive to axial movement relative to the mandrel. Responsive to increases in hydraulic pressure, the piston compresses the spring and axially moves and expands the grapple. Responsive to subsequent decreases in hydraulic pressure, the spring decompresses and axially moves and collapses the grapple. |
