Abstract: A wireline jar tool delivers instrument packages into wellbores and retrieves tools when they get stuck. The jar has several stored spring chambers connected to accelerate an upper spring chamber away from a stuck lower carrier chamber that supports instrument packages. Wireline tension actuates the jarring action and then lowers a sinker bar for reset as many times as required to incrementally jar the un-stick fish uphole. The wire line connects to a conductor that extends inside the tool through a main operating shaft, release coupling, hammer and anvil, lost motion coupling, into the lower chamber where the end connects to the instruments for communication to the surface. A small wireline tension provides unexpected large impact forces.

Abstract: A gas-generating composition comprising an oxidizer, a non-metal, preferably organic, fuel component, and a metal fuel staple component of a particular size.