Kombinerede anordninger af borehulsprop/kemisk opvarmningsanordning til anvendelse ved borehulsoperationer og tilhørende varmepatroner

The present invention provides a cartridge (1) for a chemical heater used in down-hole operations. The cartridge (1) comprises a quantity of a chemical reaction heat source (2) wrapped in a temporary coating (3) that is capable of maintaining the shape of the cartridge (1) prior to use but which is consumed during the burn of the heater. The present invention also provides a eutectic/bismuth based alloy well plugging/sealing tool (5). The tool (5) having a tubular heater body (6) with an internal cavity (8) capable of receiving a chemical heat source and a quantity of eutectic/bismuth based alloy (7) provided in thermal communication with the heater body (6) around an outer surface of the heater body (6). The tool has a sleeve (10) provided around an outer surface of the alloy (7), which insulates and/or mechanically protects the alloy (7) down-hole. In this way the sleeve (10) enables the diameter of tool (5) to be reduced whilst maintaining its functionality. In further aspect, the present invention also discloses the provision of a refractory lining (20) on the inner walls of the tubular heater body of chemical heaters, such as the heater (6) used in the eutectic/bismuth based alloy well plugging/sealing tool (5).