| 摘要 |
The present invention relates to downhole tools, and in particular an underreamer tool (1) for use in a wellbore of an oil or gas well and a method of actuation. In an embodiment, the underreamer tool (1) has body (10) having a longitudinal axis(18) and a fluid conduit, a tool element (20) and an actuation device (90) configured to urge the tool element (20) relative to the body (10) from a first configuration into a second configuration. In this embodiment, a portion (30) of the tool (1) has a curved actuation surface (30e) and as the tool element (20) is urged across the curved actuation surface (30e), the tool element (20) is moved radially with respect to the body (10) of the tool (1). Typically, the actuation device (90) may include a piston (60) driven by pressure of fluid circulated through the fluid flow conduit (16). |
