444484-A is referenced by 35 patents.
444,484. Recovering natural gas. RANNEY, L., Petrolia, Ontario, Canada. Sept. 17, 1934, No. 26685. [Class 55 (ii)] Natural gas is recovered from coal and other carbonaceous deposits in situ by gaining access to such deposit and subjecting it to a heat treatmeni appreciably below the temperature at which destructive distillation commences. The gas is thereby caused to exude or to flow into the pore spaces or passages in the deposit and so facilitate recovery. A tunnel 3 with sapping tunnels 4 may be driven into a coal seam, and to increase the exposed surface of the coal charges may be ignited in borings from the sapping tunnels. A concrete barrier 5 is then constructed in the tunnel 3 near the shaft 1.; A second tunnel system 9, 10 of a similar character is then completed and hot gas is pumped through pipes 13, 12 so as to raise the temperature of the coal 10 F. or more, and upset the unstable equilibrium by which adsorbed gas is held in the cool. This gas is driven into the tunnels 4, 3 and withdrawn through pipes 6, 7 to holders located either in the mine or at the surface. In a modification, a system of wells may be used either above or in conjunction with a tunnel system.