GVF (Gas Volume Fraction) is the volumetric gas fraction in oil + water + gas flow at operating (reservoir) conditions.
Enter liquid and gas flow rates — the calculator computes GVF and converts gas flow to standard, normal, and operating conditions.
Engineering calculator for multiphase oil + water + gas flow.
For a single-phase (liquid) meter, physics is relatively simple: one fluid with known density ρ flows in the pipe; the pressure-drop ↔ flow relation is one equation (often Q ∝ √(ΔP/ρ)), and metrology is a single curve or even one number. For multiphase flow (oil + water + gas) this breaks down for several reasons.
A multiphase meter must work where gas and liquid coexist with different densities, viscosities, and velocities. Pressure drop depends on mixture composition — GVF, phase densities, and flow regime. You cannot take a “10–100 m³/day” water range and apply it to a mixture: at the same ΔP, flow differs at GVF = 5% vs 95%.
Gas and liquid move at different speeds (slip). The same pressure drop maps to different Qgas and Qliq combinations. Classic Venturi with one “mixture” density and no phase distribution model fails — a drift-flux Zuber–Findlay model is used instead.
Flow type (bubbly, slug, annular, dispersed, etc.) depends on GVF, phase velocities, diameter, viscosity, and surface tension. For multiphase meters, regime is part of the metrology model. The GVF section here determines flow structure — meaningless for pure liquid.
Gas rate may be given at standard, normal, or operating conditions; liquid includes WLR; gas may come via GOR. All quantities are reconciled in one model with P, T, densities, and compressibility Z (Peng–Robinson from gas composition).
For multiphase Venturi: direct (ΔP → rates) and inverse (rates → ΔP) problems are solved by bisection with convergence checks — not a tabulated K-factor from a meter datasheet.
Multiphase meters must verify that the instrument covers the specified liquid and gas ranges simultaneously. This site implements that as coverage checking in Venturi sizing.
In short: multiphase metering needs mixture models, GVF, flow regime, and iterative solvers.
Calculators are grouped in the menu: Basic, Venturi, Pro. Access depends on sign-in and access level.
Fundamental gas volume fraction in oil + water + gas flow at operating conditions. With pipe diameter — flow regime from phase velocities. For engineers who need quick gas saturation and regime estimates.
Convert gas volumetric flow to a unified condition set. Input in std., normal, or operating conditions with P and T; output in all three systems.
Fast bidirectional conversion between cubic metres and oil barrels. Useful when reports and equipment mix SI and field units.
Bidirectional Celsius ↔ Fahrenheit conversion in real time. Handy when comparing inputs from international specs and datasheets.
Convert between absolute and gauge pressure. Input in Pa, kPa, MPa, bar, atm, kgf/cm², psi, mm Hg, mm H₂O; output in all units both ways.
Bidirectional pressure unit conversion: editing any field instantly updates the others.
Key tool — Venturi tube measurement range as a multiphase meter. Liquid and gas rates (range or point), PVT, geometry, ΔP and velocity limits. Results table, coverage check, Flow Map, inverse calc, PDF export with QR code.
Direct MPFM problem: from measured ΔP determine oil, water, and gas rates (drift-flux model, Peng–Robinson gas composition, well profiles, saved calculations in account).
Inverse problem: given oil, water, and gas rates, find throat ΔP. Same physics as the flow calculator.
Simultaneous calculation for seven Venturi sizes (DN48, DN77, DN94), summary table, flow map with all size contours, and range summation mode.