Abstract: Methods and apparatus for spalling a material, for example to thermally drill a wellhole, are provided. Such methods may include directing a fluid having a temperature greater than about 500° C. above the ambient temperature of the material and less than about the temperature of the brittle-ductile transition temperature of the material to a target location on the surface of the material, wherein the fluid produces a heat flux of about 0.1 to about 50 MW/m2 at an interface between the fluid and the target location, and thereby creating spalls of the material.

Abstract: Methods and apparatus for spalling a geological formation, for example to thermally drill a wellhole, are provided. Such methods may include providing a housing comprising a reaction chamber and a catalyst element held within the reaction chamber, providing at least one jet nozzle, contacting one or more unreacted fluids or solids with the catalyst element, wherein the unreacted fluid or solid is adapted to react over the catalyst element, thus generating a reacted fluid, and emitting the reacted fluid through the at least one nozzle, wherein the at least one nozzle is directed to an excavation site within or on the geological rock formation, thereby creating spalls and/or a reacted rock region.

Abstract: Methods and apparatus for spalling a material, for example to thermally drill a wellhole, are provided. Such methods may include directing a fluid having a temperature greater than about 500° C. above the ambient temperature of the material and less than about the temperature of the brittle-ductile transition temperature of the material to a target location on the surface of the material, wherein the fluid produces a heat flux of about 0.1 to about 50 MW/m2 at an interface between the fluid and the target location, and thereby creating spalls of the material.

Abstract: Methods for enhancing existing wells, such as increasing the diameter of an existing well by hydrothermal spallation are provided. Such methods may include providing a housing comprising a reaction chamber and a catalyst element held within the reaction chamber, providing at least one jet nozzle, contacting one or more unreacted fluids or solids with the catalyst element, wherein the unreacted fluid or solid is adapted to react with the catalyst element, thus generating a reacted fluid, and emitting the reacted fluid through the at least one nozzle, wherein the at least one nozzle may be directed to a production zone of an internal wall of the existing well.