Live Engineering Dashboard

Well Testing Toolbox

Interactive Tools

Engineering calculators and conversion utilities for field work.

Gas Flow Rate Estimation

Estimation through a fixed choke when Critical Flow exists (Downstream P < 0.5 × Upstream P).

Scientific Calculation Model

The Estimated Gas Flow Rate ($Q$) is calculated using the following critical flow model:

$$Q = \frac{C \cdot P_{up}}{\sqrt{T \cdot G}}$$

Where the Choke Coefficient ($C$) is derived empirically:

$$C = \left( \frac{D}{64} \right)^{2.0871} \times 26.616 \times 18$$
  • $Q$ = Flow Rate (Mscfd)
  • $D$ = Choke Size (1/64")
  • $P_{up}$ = Upstream Pressure (psig)
  • $T$ = Absolute Temperature ($^\circ F + 459.67$)
  • $G$ = Gas Gravity (Air = 1.0)