Abstract: A gas generator has an elongate combustion housing shaped to fit within a borehole for generating gasses in the borehole for use in the recovery of petroleum products. The gas generator includes a plurality of annular cooling jacket segments that surround the elongate combustion housing, each of the annular cooling jacket segments having an inlet port and an outlet port for allowing water to flow therethrough. A plurality of apertures through the elongate combustion housing allow water to flow from the plurality of annular cooling jacket segments into the elongate combustion chamber.

Abstract: A method for cooling a downhole gas generator that includes a combustion housing and a plurality of annular cooling jacket segments. A flow of water is provided into inlet ports, and out of outlet ports, of each of the plurality of annular cooling jacket segments, for cooling the downhole gas generator. The flow of water into the inlet ports, and out of the outlet ports is regulated to provide optimal cooling of the downhole gas generator, and to also optimize the flow of water through the plurality of apertures of the combustion housing and into the combustion chamber, to minimize heat damage to the combustion housing.