Invasive cryogenic tool and method for freezing the content of a pipe

A cryogenic tool for freezing a pipe content which otherwise flows through the pipe, comprising:

• an elongated tool body having a hollow tip formed of thermally conductive material, said tip being adapted for insertion through a wall of the pipe and having sufficient length to extend entirely through the wall of the pipe and into the pipe content;
• and
• a cryogenic device connected to the hollow tip, for transmitting a cryogenic fluid through a conduit into said hollow tip, said hollow tip having a larger cross-sectional area than said conduit, whereby said cryogenic fluid expands during entry into said hollow tip and absorbs sufficient heat from said content via thermal conduction through said thermally conductive material to freeze said content of said pipe in the vicinity of said tip and thereby form a plug of said content which prevents flow through the pipe.

A method of freezing a content of a pipe to prevent flow through the pipe, said method comprising the steps of:

• inserting a thermally conductive tip of a cryogenic tool through a wall of said pipe so that said cryogenic tool extends into said content;
• and
• applying a cryogenic fluid to said conductive tip so that heat from said content of the pipe is transferred through the tip to the cryogenic fluid, to vaporize said cryogenic fluid.