Abstract: In the representative embodiments of the several methods and apparatus of the invention, a barrier formed of a low-temperature fusible metal alloy having a selected melting point greater than the anticipated well bore temperatures is arranged between a receptor explosive and a typical electrically-initiated detonator enclosed in a housing for blocking the transmission of detonation forces from the detonator to the receptor explosive until the barrier has been heated by an electrical heater adjacent to the barrier. By selecting a fusible metal alloy which has a melting point higher than the known temperatures of the well bore fluids, when the tool is exposed to those elevated temperatures, the barrier will be predictably maintained in its solid state to continue blocking the detonation path of the donor explosive if the heater fails thereby allowing the well tool carrying the explosives to be safely recovered from the well bore.

Abstract: In the representative embodiments of the several methods and apparatus of the invention, a barrier formed of a low-temperature fusible metal alloy having a selected melting point is arranged between the donor and receptor explosives in an otherwise-typical detonator for reliably blocking the transmission of detonation forces from the donor explosive to the receptor explosive until the detonator has been subjected to well bore temperatures which are greater than the melting point of the fusible alloy. By selecting a fusible metal alloy which has a melting point less than the known temperatures of the well bore fluids, when the tool is exposed to those elevated temperatures, the barrier will be predictably transformed to its liquid state thereby allowing the liquid alloy to flow to a non-blocking position away from the detonation path of the donor explosive.

Abstract: In the representative embodiments of the several methods and apparatus of the invention disclosed herein, a movable detonating member is arranged to be selectively impelled against an impact-responsive detonator on a well tool having one or more explosive devices. The movable detonating member is initially restrained from moving in relation of the tool body by a heat-responsive material which, in one embodiment, is operative to release the detonating member when an electrical heater on the tool is initiated from the surface for melting the bonding material or, in another embodiment, releases the detonating member when the material is melted by elevated well bore temperatures.

Abstract: In the representative embodiment of the apparatus of the invention disclosed herein, a circular fluid deflector with a central opening to receive a pump shaft is arranged with a flat transverse face for facing the seal in the pump housing through which the shaft is extended. Fluid-deflecting surfaces are arranged on the deflector including a peripheral rim having an outwardly-diverging inclined surface and one or more annular ribs coaxially disposed between the central opening and the rim which respectively have surfaces facing the shaft seal so that whenever fluids leaking through the shaft seal strike any of these fluid-deflecting surfaces these fluids will be directed outwardly from the deflector member to provide a fluid screen to divert other leaking fluids that would otherwise pass around the deflector and contact adjacent equipment such as the prime mover for the pump.

Abstract: The invention relates to a tool suitable for closing a production column (100) of a well when the tool is located in a connector of enlarged diameter (101). The tool is lowered on the end of a cable (76) and includes a tilting valve member (60) which is oblong in shape and which is oriented longitudinally to pass through the corresponding oblong orifice of a valve seat (69) fixed to the connector, and is then oriented transversely in order to co-operate with said seat in order to close the production column when a traction force (F) is applied to the cable (76).

Abstract: In the representative embodiment of the present invention described herein, several new and improved methods and apparatus are disclosed for simultaneously massaging the upper and lower back portions of a person lying face-up in a supine position on an upwardly-facing surface.