*2.1. Materials*

#### 2.1.1. CBM Reservoir Sample

The reserves of CBM resources are 2.8 billion m<sup>3</sup> and the abundance of resource reserves is 0.43 m<sup>3</sup>/km<sup>2</sup> in the Lengshuijiang mining area in central Hunan. The development prospect is broad. CBM reservoir sample of Lengshuijiang mining area was selected and made into ϕ20 mm × 10 mm standard sample which has the same bedding direction and similar structure. Rock powder was obtained by crushing some samples and passing a 200-mesh sieve.
