NorCraft Software
We make easytouse engineering software for the oil & gas industry. Our software is designed for practical field applications, and the programs have been tested and proven for both onshore and offshore oil and gas installations. The programs are designed for use right away, easy, clutterfree and fast.
The programs are provided "as is” without warranty of any kind, either expressed or implied, including any warranty of merchantability or fitness for a particular purpose. In no event shall the author or Norcraft be held liable for any loss of profit, special, incidental, consequential, or other similar claims.
The programs are written as Excel macros and require Microsoft Excel version 2007 or later. 'Macro' must be enabled within Excel to run the programs. The DEMOversions received through the direct download link have limited functionality and will only work a few times. A license fee of $9.95 for each program is required for a full version of the program, which will be emailed to you.



ISO5167: 2003 Orifice Calculations 









Free Manual 
GOWDoc (Documentation File) – Free PDFfile 


For more information, please send questions/queries to: 

OilGasApp@gmail.com 
AGA3 and ISO5167 Orifice Calculations
Programs AGA3 and ISO5167 will size orifice plates for given design conditions, find pressure drop for a given flow, or flow for a given pressure drop. The standards (AGA3 ( API2530: 1991) and ISO5167: 2003) are originally designed for gas orifices. In these programs they are also used for liquid orifices.
The gas orifices are Natural Gas, Nitrogen and Air. The fluids for liquid orifices are Crude Oil, Water, Methanol, Monoethylene glycol, diethylene glycol and triethylene glycol.
For gascalculations you have to enter specific gas gravity, temperature and pressure. You can also give molefractions of N2, CO2 and H2S for sour gas calculations.
The AGA8 equation is used for calculating Zfactor (compressibility factor) for natural gases, and the RedlichKwong equation of state for air and nitrogen.
For oilcalculations you have to enter specific oil gravity, temperature and pressure. It is also recommended to give molecular weight of oil. For watercalculations the input requirements are salinity, temperature, and pressure.
NOTE: It is assumed that all dissolved solids for water are expressed as equivalent sodium chloride concentration.
The results are an orifice specification sheet giving the necessary data for design of an orifice or evaluating an existing orifice.
The results will contain a few factors that you should know:
The velocity of approach factor is defined as:
Ev = 1/(Sqrt(1Beta^4))
The flow coefficient, Alpha, is defined as:
Alpha = Ev * Cd
and orifice to pipe diameter ratio is given as:
Beta = OD/PID
API/ ANSI2530  1991 (AGA Report No. 3) (AGA)
The basic flow equation is:
Qv = Fn*(Fc+Fsl)*Y1*Fpb*Ftb*Ftf*Fgr*Fpv*Sqrt(Pf1*hw)
where
Fn = Numeric conversion factor
Cd = Discharge coefficient = (Fc + Fsl)
Fc = Orifice calculation factor
Fsl= Slope factor
Y1 = Expansion factor based on upstream tap
Fpb= Pressure base factor, set to 1.0 (14.73 psia)
Ftb= Temperature base factor, set to 1.0 (60 deg F)
Ftf= Flowing temperature factor
Fgr= Specific gravity factor
Fpv= Supercompressibility factor
Pf1= Absolute flowing pressure based on upstream tap
hw = Orifice differential pressure, in H2O at 60 deg F
The above equation is often simplified to:
Qv = C' * Sqrt(Pf1*hw)
where C' is called the Composite orifice flow factor.
For other factors and the factors for pipe taps you are advised to consult the standard API25301991, Part 3.
ISO51672: 2003 ( ISO)
The basic flow equation is:
Qm = C*E*Eps*Pi/4*OD^2*Sqrt(2*dP*Roh)
where
Qm = Mass flow rate (kg/s)
C = Discharge coefficient = Alpha/E
E = Velocity of approach factor = 1/(Sqrt(1Beta^4))
Eps = Expansion factor due to pressure drop
Pi = 3.14159
OD = Orifice diameter at actual flowing conditions
dP = Differential pressure across orifice
Roh = Density of flowing fluid measured at upstream tap
For other factors consult the standard ISO51672: 2003.
Program WatGas  WaterNatural Gas Phase Behavior Calculations
Watgas calculates WaterNatural Gas interaction properties, including the following PVTproperties:
Hydrate formation calculations
Water content predictions of natural gases
Inhibitor quantities (methanol/glycols) to avoid hydrate problems in pipelines
Solid CO2 formation predictions
The program handles gases with known compositions and noncompositional gases (only gas gravity is needed). Note that the compositional model is more reliable than the noncompositional model, although they give similar results.
Almost all gases contain some water vapor. When leaving the producing formation, gas is saturated with water vapor, which is in equilibrium with reservoir liquid water at temperatures and pressures prevailing there.
Knowing the water content of natural gases is essential to the design and operation of production, dehydration and transmission systems. Water may condense in production and gathering systems. This may result in hydrate formation and plugging of flow systems and damage to internals of production equipment.
Condensed water may form water slugs, which will tend to decrease flow efficiency and increase the pressure drop in a line. Presence of free water in pipeline systems may also cause corrosion. If carbon dioxide and/or hydrogen sulfide are present, the gases may form carbonic acid and sulphurous acid respectively if dissolved in water.
Program GOWProp (GasOilWater Physical Properties)
Program GOWProp is a Physical Properties program that calculates PVT properties of gas, oil, and water — with your choice of calculation methods. Pick from a selection of standard equations for calculating certain properties. More than 12 properties are calculated and the results include a pressure depletion table of the various properties and will plot the output on screen. U.S. and SI Units.
Oil properties are calculated based on a blackoil model. In fluidproperty terms the blackoil model employs 2 pseudocomponents:
1) "OIL" defined as produced oil at stock tank conditions
2) "GAS" defined as produced separator gas
The basic assumption is that gas may dissolve in the oil phase, but oil will not dissolve in the gas phase. For mixtures of heavy oil and light components this is a reasonable assumption, but is a misleading assumption for mixtures of light and intermediate components.
The following fluids are included:
Gases:
Natural gas
Nitrogen
Air
Liquids:
Oil
Water
Methanol/Water mixtures
Monoethylene glycol/Water mixtures
Diethylene glycol/Water mixtures
Triethylene glycol/Water mixtures
GOWProp will let you choose between SIunits (metric) or Customary units.
The gas property routine calculates:
Molecular weight
Density
Compressibility
Gas formation volume factor
Zfactor (gas deviation factor)
Viscosity
Thermal conductivity
Specific heat
Ideal isentropic coefficient, Cp/Cv
Real isentropic coefficient, k
Pseudo Critical properties
Pseudo Reduced properties
The liquid property routine calculates:
API gravity (for oil only)
Density
Compressibility
Formation volume factor (oil and water only)
Solution gasliquid ratio (oil and water only)
Bubble point pressure (oil only)
Viscosity
Thermal conductivity
Surface tension
Specific heat
Pseudo Critical properties
Pseudo Reduced properties
A pressure liberation table of properties (at constant temperature) will also presented from given pressure down to atmospheric conditions (14.696 psia [1.01325 Bara]).
Program GOSep (GasOil Separtor Flash Calculations)
Program GOSep performs flash calculations for gas/oil separators to optimize liquid recovery. The program performs vaporliquid equilibrium calculations for 2 stages of separation and Stock Tank conditions (Standard Conditions), defined in the program as 14.73 psia and 60 °F.
Equilibrium ratios (Kvalues) are used for calculating compositions of gas and liquid phases at given temperatures and pressures. Normally an equation of state (EOS) is used for predicting equilibrium ratios, and is a function of composition, pressure and temperature. Based on the fact that compositional effects on equilibrium ratios are small below about 1000 psia, Standing developed a correlation for calculating equilibrium ratios based on data reported by Katz and Hachmuth. The correlation gives the following equation for each component:
K = (1/P) x 10 ^{(a + c x F) }
where
F = b x (1/Tb  1/T)
K = equilibrium ratio
a, b, c = correlating parameter
P = pressure, psia
T = temperature, deg R
Tb = boiling point, deg R
X = mole fraction in liquid phase
y = mole fraction in vapor phase
Last Revised: April, 2014