Cup tool for a high-pressure mandrel and method of using same

#This is the first application filed for the present invention.

#Not applicable.

#This invention generally relates to wellhead isolation equipment and, in particular, to a cup tool for a high-pressure mandrel used for isolating a wellhead.

#Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, in which:

#FIG. 1 is a cross-sectional view of a prior-art cup tool for a high-pressure mandrel;

#FIG. 2 is a cross-sectional view of a cup tool for a high-pressure mandrel in accordance with an embodiment of the invention wherein a gauge ring is slipped onto the cup tool;

#In general, as will be explained below, the invention provides a cup tool for providing a high-pressure fluid-tight seal in an annular gap between a high-pressure mandrel and a casing or a production tubing in a wellbore. The cup tool includes a cup tool tube having a threaded upper end for connection to the high-pressure mandrel and an elastomeric cup that is slidably received on an outer surface of the cup tool tube. When the cup is exposed to elevated fluid pressures, a top end of the elastomeric cup is forced up over an annular step (jump step) into abutment with a gauge ring, which causes the cup to move into a set position in which the cup extrudes into the annular gap to provide the high-pressure fluid seal. A bullnose, or the like, is threaded to a bottom of the cup tool tube to protect the cup while guiding the cup tool through a wellhead. The annular jump step inhibits premature setting of the elastomeric cup during insertion of the cup tool through restrictions in the wellhead or tubing string.

#FIG. 2 illustrates a cup tool 10 in accordance with one embodiment of the invention. The cup tool 10 includes a cup tool tube 12. The cup tool tube 12 has a set of upper pin threads 14 for connection to a high-pressure mandrel (not shown in this figure). The cup tool tube also includes a set of lower pin threads 16 for connection to a bullnose 18. In one embodiment, the bullnose 18 has an annular groove 19 that receives an annular sealing element such as an O-ring or ring gasket for providing a fluid-tight seal between the bullnose 18 and the cup tool tube 12.

#As shown in FIG. 2, the cup tool 10 includes an elastomeric cup 24 that is slidably mounted over an outer surface of the cup tool tube as described in Applicant's U.S. Pat. 6,918,441 referenced above.