mir911, page-86

Yes, it's definitely possible. It depends on several factors including the storage capacity of the coal as well as the gas content. It's quite a complex relationship between different coal macerals, ash and moisture content, rank, pressure, temperature etc. It also depends on what lithologies are adjacent to the seam, such as permeable sandstones. You also have measurement error which makes it hard to know exactly what the true saturation is with any accuracy.

Generally speaking though saturations in a big thick seam like this would tend to be fairly similar because the gas would diffuse through the seam to reach equilibrium.