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Low temperature barriers for use with in situ processes

  • US 7,546,873 B2
  • Filed: 04/21/2006
  • Issued: 06/16/2009
  • Est. Priority Date: 04/22/2005
  • Status: Expired due to Fees
First Claim
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1. A method of forming and maintaining a low temperature zone around at least a portion of a subsurface treatment area, comprising:

  • reducing a temperature of heat transfer fluid with a refrigeration system;

    circulating the heat transfer fluid through freeze well canisters placed in a formation around at least a portion of the subsurface treatment area, wherein at least one freeze well canister is formed from longitudinally welded sheet metal, wherein an initial temperature of the heat transfer fluid supplied to a first freeze well canister is in a range from about −

    35°

    C. to about −

    55°

    C., and wherein at least one of the well canisters comprises carbon steel; and

    returning the heat transfer fluid to the refrigeration system.

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