US Patent 11787993 In-situ foamed gel for lost circulation

A system and method for treating lost circulation, including providing a treatment fluid including a polymer and a nitrogen-generating compound through a wellbore into a lost circulation zone in a subterranean formation, generating nitrogen gas in the lost circulation zone by a reaction of the nitrogen-generating compound, generating foam from the nitrogen gas and the treatment fluid in the lost circulation zone to give foamed polymer in the lost circulation zone, and plugging the lost circulation zone with the foamed polymer.