A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed...http://www.google.es/patents/US7527094?utm_source=gb-gplus-sharePatente US7527094 - Double barrier system for an in situ conversion process
Double barrier system for an in situ conversion process
