Patent ID: 8002032

Claim:
A hydraulic overshot apparatus with a removable setting and testing core, comprising: a. a first lower portion, attachable and positioned around an upper end of open tubing, under pressure; b. a second upper portion, positioned in the first lower portion; c. means for injecting fluid under pressure into the upper portion for sealingly engaging the first lower portion to an outer wall of the tubing and simultaneously sealing the upper portion to an inner wall of the tubing; d. means for injecting a test fluid under pressure to test the integrity of seals between the apparatus and the outer wall and inner wall of the tubing; and e. a valving element for releasing the pressure between the upper portion and the inner wall of the tubing and removing the upper portion so that the lower portion remains sealing engaged to the wall of the tubing for attaching devices to conduct workover of the tubing under pressure.