Shock energy absorber including collapsible energy absorbing element and

Abstract

A shock absorber is adapted to be disposed within a perforating gun string or within the tubing string above the perforating gun and includes an energy absorbing element adapted to absorb and store mechanical energy during detonation of the perforating gun and to permanently deform in response to the storage of the mechanical energy, the stored energy being released in the form of heat, and not in the form of kinetic energy. Therefore, following absorption of the mechanical energy by the shock absorber, no further expansion of the shock absorber is experienced. The shock absorber includes an inner housing, an outer hosuing, a connection for interconnecting the inner and outer housing, and a break up charge for breaking the connection and releasing the inner housing from the outer housing when the perforating gun is detonated whereby the shock absorber is as strong as the tubing string before the connection is broken and is flexible after the connection is broken. The energy absorbing element may be a damping coil or it may be a honeycomb. The damping coil and honeycomb energy absorbing elements permanently deform when mechanical energy is absorbed; therefore, the stored mechanical energy is subsequently released in the form of heat and not in the form of kinetic energy.