I would prefer if it was over 50m in total
let me explain.
I spoke to my engineering friends who have worked on oil and gas projects. The main question is not whether how many metres of coal seams but its how many metres are commercially viable to be producing at certain rate.
It is also about how much impurity is in the content. If the content we get out is around 80-90% methane then it will be good. We would also need to include the amount of water and other elements that come up when we extract the gas.
I showed him the jixi operation, he told me the donkey pump is sucking out water and so on.. so at the end of the day we need to know how clean the gas content is.
He did mention something about some people around the world were trying to burn the coal underground via a process but not sure how successful that was.