Abstract: For lost circulation treatment, a lost circulation additive including a dry mixture of water soluble crosslinkable polymer, a crosslinking agent, and a reinforcing material of fibers and/or comminuted plant materials. The method of forming a lost circulation fluid includes contacting the additive with water or an aqueous solution, with a method of conforming the formation further including the step of injecting the fluid into the wellbore.

Abstract: A composition comprising (a) a resin composition comprising a block copolymer of the formula hydrocarbon-polyether-polyamide-polyether-hydrocarbon; and (b) a polar liquid. The block copolymer may be prepared by a process comprising reacting together reactants comprising dimer acid, diamine, and a polyether having termination at one end selected from amine, hydroxyl and carboxyl, and termination at another end selected from hydrocarbons. The polar liquid may be one or more of an aromatic liquid, a polar aprotic liquid, a ketone-containing liquid, an ester-containing liquid, an ether-containing liquid, an amide-containing liquid and a sulfoxide-containing liquid. The composition may be a gel at room temperature.