NOVELTY - Method-I for converting natural gas and water (110) into a gas mixture of carbon dioxide and hydrogen, comprises: (a) combusting a portion of the natural gas with an oxidizing agent to generate heat, superheated steam (107); (b) steam reforming the gas mixture with additional superheated steam; (c) water-gas-shifting any residual carbon monoxide into additional carbon dioxide and additional hydrogen; (d) boiling water in a top-to-bottom linear countercurrent heat exchanger; and (e) utilizing the superheated steam to assist in reformation of the natural gas into carbon dioxide and hydrogen.    USE - The method-I is useful for converting natural gas and water into a gas mixture of carbon dioxide and hydrogen, and for enabling oil recovery and production of low-carbon emission electricity utilizing natural gas and water (all claimed).    ADVANTAGE - The method enables enhanced oil recovery and economically produces the low-carbon emission electricity. The method produces large quantities of carbon dioxide, hydrogen and other gases from a natural gas source at low cost at or near an oil site, and provides a compact, portable natural gas steam reformer.    DETAILED DESCRIPTION - Method-I for converting natural gas and water (110) into a gas mixture of carbon dioxide and hydrogen, comprises: (a) combusting a portion of the natural gas with an oxidizing agent to generate heat, superheated steam (107), and a gas mixture of carbon dioxide, carbon monoxide and hydrogen; (b) steam reforming the gas mixture with additional superheated steam under steam-rich conditions to transform a remaining portion of the natural gas into carbon dioxide, carbon monoxide and hydrogen; (c) water-gas-shifting any residual carbon monoxide into additional carbon dioxide and additional hydrogen by utilizing a water-gas-shift catalyst downstream of the steam reforming step, thus producing an effluent gas mixture that is predominantly carbon dioxide and hydrogen; (d) boiling water in a top-to-bottom linear countercurrent heat exchanger to generate the superheated steam by transferring heat released in the water-gas-shifting step, where as the water is gravitationally and thermally stratified from top to bottom with a top portion boiling into steam, the steam continues to rise and is additionally heated in the top-to-bottom linear countercurrent heat exchanger; and (e) utilizing the superheated steam produced as a reactant in the steam reforming step and the water-gas-shifting step to assist in reformation of the natural gas into carbon dioxide and hydrogen. INDEPENDENT CLAIMS are included for:    (1) a method-II for converting natural gas and water into a synthesis gas mixture of carbon monoxide and hydrogen, comprising combusting a portion of the natural gas with an oxidizing agent to generate heat, superheated steam, and a gas mixture of carbon monoxide and hydrogen, with a less carbon dioxide, steam reforming the gas mixture under steam stoichiometric conditions with additional superheated steam to transform a remaining portion of the natural gas into the synthesis gas mixture of carbon monoxide and hydrogen, substantially free of carbon dioxide, boiling water in a top-to-bottom linear countercurrent heat exchanger to generate the superheated steam by transferring heat released in the combusting step, where as the water is gravitationally and thermally stratified from top to bottom with a top portion boiling into steam, the steam continues to rise and is additionally heated in the top-to-bottom linear countercurrent heat exchanger, and utilizing the superheated steam produced as a reactant in the steam reforming step to assist in reformation of the natural gas into carbon monoxide and hydrogen, thus producing an effluent gas mixture that is predominantly carbon monoxide and hydrogen; and    (2) enabling oil recovery and production of low-carbon emission electricity utilizing natural gas and water, comprising the steps (a)-(d) as above per se, boiling additional water in an external boiler by combusting the natural gas with ambient air to generate additional superheated steam which is fed into the steam reforming step, the step (e) as above per se, separating the carbon dioxide and hydrogen into two streams, one predominantly carbon dioxide and the other predominantly hydrogen, compressing the carbon dioxide stream and injecting it into the ground to enable oil recovery, and utilizing the hydrogen stream in a power generator to produce electricity with low carbon emissions, where some of the waste heat from the power generator may be used to boil water to generate additional steam to feed the steam reforming step.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a steam natural gas reformer.    Superheated steam (107)    First enclosure (108)    Water (110)    Second enclosure (112)    Channels. (120)