Page 82 - Handbook of Natural Gas Transmission and Processing Principles and Practices
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moderate pressures, the crude oil is in a vapor-liquid state (note that the gas state is generally only
found at very low pressure). For a gas condensate, it is possible to define two dew points at the
temperature of the mother rock (retrograde condensation phenomenon). Hence a gas condensate is in
a gaseous state at low or high pressures but exhibits 2-phase equilibria at intermediate pressures. A
natural gas is fully gaseous at the mother rock temperature, regardless of the pressure value.
FIGURE 2.9 Schematic representation of the shapes of phase envelopes for size-symmetric and size-
asymmetric mixtures.
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