Volume ratios presented here relate the volume (V_m) of one mole of 100% methane gas at the relevant in-situ pressure and temperature to the volume (V_STP) of one mole of the same gas at standard conditions. Standard temperature and pressure (STP) are defined as T = 0°C or 273.15 K, P=1 atmosphere or 0.101325 MPa. At STP, V_m = 22,346 cm³/mol = V_STP.

Volume Ratio = V_STP/V_m

Volume ratio can be seen as an expansion factor describing the expected change in volume in bringing the methane from depth conditions to standard surface conditions. For dry gas, it is the reciprocal of the formation-volume factor (Hagoort, 1988). In this report, all volumes are compared back to the same standard temperature and pressure condition (STP). This approach facilitates estimation of resource volumes and allows direct comparison with gas yields from other settings.