Patent ID: 7775280
Filing Date: 2010-08-17
Classification: E21B

Abstract:
1. A method of dislodging a tool stuck downhole in a wellbore, comprising: connecting a jarring apparatus to a tool via a wireline, the jarring apparatus comprising a first sub-assembly disposing a first spring, a second sub-assembly disposing a second spring, a third sub-assembly disposing a third spring and a forth sub-assembly, wherein the first sub-assembly is attached to a wireline, the forth sub-assembly is attached to the tool and the second sub-assembly and the third sub-assembly are disposed between the first and the forth sub-assembly; compressing the third spring in response to applying tension to the wireline moving the first sub-assembly, the second sub-assembly and the third sub-assembly away from the stuck tool; moving the first sub-assembly, the second sub-assembly and the third sub-assembly toward the stuck tool in response to releasing the tension in the wireline; compressing the first spring and the second spring in response to moving the first sub-assembly, the second sub-assembly, and the third sub-assembly the third tool toward the stuck tool; expanding the third spring in response to compressing the first and the second springs; and jarring the stuck tool downward in response to the force of the expanding third spring and the impact of the first sub-assembly, the second sub-assembly and the third sub-assembly on the stuck tool via the forth sub-assembly.