Apparatus, methods, and systems for extracting oil or natural gas from a well using a portable coal reformer. In one example, the method may include reforming coal by reaction with water to generate driver gas (comprising carbon dioxide and hydrogen gas), and injecting the driver gas into the well. The driver gas reduces the viscosity and pressurizes the oil to help extract the oil from the oil well. The coal reforming operation may include combusting coal or other combustible material with ambient oxygen to release energy, and heating coal and water with the energy released to a temperature above that required for the coal reforming reaction to proceed, thereby reforming coal and water into driver gas. The driver gas may be purified by filtering out particles and sulfur before injecting into the well. A portion of the hydrogen gas may be separated from the driver gas and used to generate electrical power.