Abstract: Methods and apparatus for excavation of a borehole in a geological formation are provided. Such methods may include providing a thermal system capable of providing substantially hot fluid, and comprising at least one jet nozzle, providing a mechanical drilling system comprising a drill bit, directing the substantially hot fluid through the jet nozzle towards the geological formation causing an altered portion of geological formation to form, and removing the altered portion using the drill bit, thereby creating cuttings and producing a borehole in the geological formation.

Abstract: Methods and apparatus for excavation of a borehole in a geological formation are provided. Such methods may include providing a thermal system capable of providing substantially hot fluid, and comprising at least one jet nozzle, providing a mechanical drilling system comprising a drill bit, directing the substantially hot fluid through the jet nozzle towards the geological formation causing an altered portion of geological formation to form, and removing the altered portion using the drill bit, thereby creating cuttings and producing a borehole in the geological formation.

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.

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.