In this work, gas genesis (methane) in coals from Lorraine (France), Warrior and San Juan (USA) Basins are studied using classical petrographic parameters such as vitrinite reflectance and maceral analysis.
Petrographic characterization allow the visualization of the transformations in organic compounds which are responsible for coal hydrocarbon generation. Determination of the onset in the gas window is also possible from petrographic results. Coal samples studied here show similar chemical composition and thermal evolution, and therefore, the Lorraine basin could have a methane production capacity similar to th a t o f the American basins (Warrior and San Juan)