Releasing and circulating overshot

The releasable universal overshot is a very suitable tool for externally engaging, packing off and pulling out the fish. The overshot has three main part: the top sub, body and guide. It may be assembled either with a spiral graple (if the fish diameter is near maximum size for the particular overshot) or with a basket grapple (if the fish diameter is considerably below the maximum catch size). According to this different type and size of control ring and top seal belong to the internal parts. As the top of the fish is reached, slowly rotate the overshot (with the fishing string) to the right and lower them into the fish gradually. Stop with the rotation, release any right-hand torque in the fishing string and pull up the fish by elevating the fishing string. If the fish is caught, start the circulating pump and maintain a heavy upward strain while the fluid is forced through the fish. Bump down the weight of fishing string heavily against the overshot, then rotate to the right and slowly elevate the fishing string. Rotation will prevent grapple from biting while overshot is removed from fish.