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Gas Flow Rate Calculator

Convert gas flow rates between standard surface conditions and reservoir conditions. Calculate z-factor and gas expansion factor. Convert between Mscf/d, MMscfd, and Mcm/d.

Gas Properties & Conditions

Surface Gas Rate (Mscf/d)

Reservoir Pressure (psia)

Reservoir Temperature (°F)

Gas Specific Gravity, γ_g

Z-Factor (override, optional)

Standard Conditions Pressure (psia)

Results

Z-Factor

Bg (RB/Mscf)

Reservoir Rate

RB/d

MMscfd

Annual Volume

Bcf/yr

Gas Density (reservoir)

lb/ft³

Mcm/d (SI)

thousand m³/day

Gas Expansion Factor

scf/RCF

Equations

Z-factor: Simple Pitzer correlation (approximation); use Well Log Z-Factor for high accuracy.

Gas Formation Volume Factor: Bg = 0.02829 × z × T / P [RB/Mscf] (T in Rankine)

Reservoir rate: q_res = q_sc × Bg [RB/d, q_sc in Mscf/d]

Gas Expansion Factor: E = P / (z × T × 0.02829 × P_sc) [Mscf/RB]

Conversions: 1 MMscfd = 1000 Mscf/d; 1 Mscf = 28.317 m³ (standard)

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