Production of synthesis gas from a coal formation

A method for in situ production of synthesis gas from a coal formation, comprising:

• heating a section of the formation to a temperature sufficient to allow synthesis gas generation, wherein a permeability of the section is substantially uniform and greater than a permeability of an unheated section of the formation when the temperature sufficient to allow synthesis gas generation in the formation is achieved;
• providing a synthesis gas generating fluid to the section to generate synthesis gas;
• controlling the heating of the section and provision of the synthesis gas generating fluid to maintain a temperature in the section above the temperature sufficient to generate synthesis gas;
• and
• removing synthesis gas from the formation.