The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 2016
Filed:
Jul. 24, 2013
Smith International, Inc., Houston, TX (US);
Stephen Hekelaar, Spring, TX (US);
Smith International, Inc., Houston, TX (US);
Abstract
A spearing device for removing casing from wellbore includes a top sub, a bottom sub, and a mandrel coupled to the top and bottom subs. The device includes a grapple having a corrugated inner surface corresponding to a corrugated portion of the mandrel and an outer surface including wickers for engaging an interior surface of the casing. A piston is disposed within the mandrel and operatively coupled to the grapple. A spring operates with the piston and biases the grapple toward a collapsed position. The grapple axially and rotationally moves along the corrugated outer surface of the mandrel. The grapple expands and collapses in response to axial movement relative to the mandrel. The piston compresses the spring and axially moves and expands the grapple in response to increases in hydraulic pressure. In response to subsequent decreases in hydraulic pressure, the spring decompresses and axially moves and collapses the grapple.