Catalytic downhole reactor and steam generator

Abstract

A Downhole catalytic Methanator reactor assembly is hung within the cemented casing of a vertical well for the purpose of producing large volumes of high quality steam and oil soluble gases for injection into horizontal drainholes drilled into a deep Heavy Oil reservoir, in order to make the Heavy Oil more mobile. Steam is generated in part by the heat of chemical reactions taking place within the reactor assembly. The exothermic Methanation reaction takes place within a fixed bed of catalyst particles, at a temperature below 800.degree. F., when a Syngas feed (H2,CO and/or CO2) comes in contact with a catalyst. Boiler feed water supplied to the reactor assembly from the surface is vaporized in boiler-type water tubes immersed in the catalytic bed, or by direct contact with the catalyst and with the hot gas phase flowing through the bed. The Syngas feed may be supplied to the reactor from the surface, or made directly by Partial Oxidation of Natural Gas in Oxygen within the downhole assembly. The reactor assembly may also be located within a cemented metal-lined cavity under-reamed below a cased access well. For operating each of the horizontal drainholes successively in the cyclic ("huff and puff") mode, a downhole valve section is included in the assembly. Multi-way downhole retrievable valves are used for this purpose. This apparatus presents the advantage of largely reducing the steam heat losses in surface lines and in well tubings.

Dependencies are inferred from the claim text.