| 摘要 |
A downhole retrieval tool for engaging and retrieving an object from a wellbore includes a mandrel and a grapple having a contracted position and an expanded position. In the expanded position, the grapple engages the object for retrieval. The grapple is operably associated with an expansion member disposed on the mandrel to facilitate movement of the grapple between the contracted and expanded positions. The expansion member is releasably connected to the mandrel. In the event that the downhole tool and object, once secured to each other, are unable to be retrieved from the wellbore, the expansion member can be released from the mandrel which, in turn, causes the grapple to release from the object so that the downhole tool can be removed from the wellbore. A stored energy member facilitates movement of the grapple from the contracted position to the expanded position. |
| 主权项 |
1. A downhole tool for engaging an object in a wellbore, the downhole tool comprising:
a mandrel having an upper end, a lower end, and an outer wall surface; a slip member in sliding engagement with the outer wall surface of the mandrel, the slip member having a fully contracted position defining a fully contracted diameter, a fully expanded position defining a fully expanded diameter, and a plurality of contracted positions each having a respective variable contracted diameter, the fully expanded diameter being greater than the fully contracted diameter, and each of the variable contracted diameters being less than the fully expanded diameter and greater than the fully contracted diameter; an expansion member disposed on the outer wall surface of the mandrel and operatively associated with the slip member to move the slip member between the fully contracted position and the fully expanded position; and a mechanical release member, the expansion member being mechanically releasably secured to the outer wall surface of the mandrel by the mechanical release member, the expansion member including a first position and a second position, the first position being in operable contact with the slip member to facilitate movement of the slip member between the fully contracted position and the fully expanded position, and the second position being out of operable contact with the slip member; wherein the mechanical release member selectively secures the expansion member in the first position, wherein the mechanical release member inhibits movement of the expansion member upwards, downwards, and around the mandrel, and wherein the actuation of the mechanical release member permits the expansion member to slide along the mandrel from the first position to the second position. |
