Opencast Mining - Mine Planning, Opening of coal seams and preparation for excavation box cut, types selection of site formation of production benches ripping types of rippers concept of rip ability and cycle of operation drilling blast hole drills performance parameters requirement of number of drills blasting blast design.Morgan H. Mosser, in Coal Bed Methane (Second Edition), 2020 23.1 Introduction. The extraction and recovery of coal bed methane and coal mine methane is an integral contributing part of the natural gas production in the United States accounting for 980 BCF per annum in 2017. The gas from premining drainage and planned degassing is generally of high quality requiring only compression and.