| 主权项 |
1. A downhole jarring apparatus for use in jarring an object in a bore, comprising:
a first jarring portion including a first impact surface; a second jarring portion including a second impact surface; wherein the apparatus is configurable from a disabled configuration in which the impact surfaces are prevented from being axially impacted together, and a jarring configuration in which the impact surfaces are permitted to be axially impacted together and generate an impact force therebetween, and during reconfiguration of the apparatus from the disabled configuration to the jarring configuration initial engagement of the first and second impact surfaces generates an impact force therebetween, and wherein the apparatus is reconfigurable from the jarring configuration to the disabled configuration to permit the apparatus to be resettable, wherein the apparatus further comprises a rotatable jarring arrangement operable to translate a rotational drive movement to cause relative axial movement of the first and second impact surfaces to establish axial impact therebetween when the apparatus is configured in the jarring configuration. |
