Vasquez-Beggs
| Light oils, Medium oils | The Vasquez-Beggs correlation was developed using laboratory results from more than 600 crude oil systems, and measured over wide ranges of pressure, temperature, oil gravity and gas gravity. The reported error for solution GOR and oil formation volume factor were -0.7% and 4.7%, respectively. | | **Standing** | Light oils, medium oils | 50 experimentally determined data points on 22 different oil-gas mixtures from California were used in the development of the correlations. | | **De Ghetto** |Light, medium, heavy and extra heavy oils
| The De Ghetto model is a model especially optimized for heavy and extra heavy oils, although it may also be used for lighter oils. The model implements modified correlations of Standing and Vasquez-Beggs for heavy oils, and uses the standard correlations for all other oils. | ### **Multiphase Flow Models** | Model | Used for | Description | | --------------------------------------------- | ---------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | |Hagedorn-Brown
|Vertical well
Oil or Oil & Gas
|The Hagedorn and Brown method was developed by obtaining experimental
pressure drop and flow rate data from a 1500 ft deep instrumental well.
Pressures were measured for flow in tubing sizes ranging from 1 ¼” to 2 ⅞”
in O.D. A wide range of liquid rates and gas/liquid ratios were included,
and the effects of liquid viscosity were studied by using water and oil as the
liquid phase. The oils used had viscosities at stock tank conditions of 10, 35
and 110 cP. The Hagedorn and Brown method has been found to give good
results over a wide range of well conditions and is one of the most widely
used well flow correlations in the industry. The Hagedorn and Brown
Correlation gives best results for wellbore with low to moderate liquid
volume fractions (high GOR) and relatively high mixture velocities
(annular-mist or froth flow).
Horizontal well
Oil or Oil & Gas
|The Beggs & Brill model is developed for tubing strings in inclined wells and
pipelines for hilly terrain. This model results from experiments using air
and water as test fluids over a wide range of parameters given below:
Vertical wells
Oil or Oil & Gas
|For oil gravity less than 30° API. Most applicable for wellbores with GOR
up to 5000.
Vertical well
Gas, Gas & Condensate
|The Gray correlation is one of the most commonly used methods for
gas-condensate well pressure profile prediction. The correlation notes
that caution should be used for the following conditions:
Gray Modified
| Vertical well Gas-condensate | Modified version of the Gray model. | | **Duns & Ros** | Vertical flow of gas and liquid mixtures in wells |Perform well for wells with high gas-liquid ratios
(usually in mist flow regime) and condensate wells
Vasquez-Beggs
| Light oils, Medium oils | Vasquez & Beggs correlation from 1978 was based on a large data base, and is therefore applicable to a wide range of oils. An average error of -7.54% was reported. | | **Standing** | Light oils. Medium oils | This model, often referred to as either Beal or Standing, was developed by Beal and fitted by Standing. It is valid for Oil gravity: 15-53°API and Reservoir temperature of 100-229°F. | | **Egbogah** |Light, Medium & Heavy oils
| Based on the work of Beggs & Robinson, Egbogah & Ng proposed a new empirical viscosity correlation for heavy oils. The model range is Oil gravity: 5-58°API and Reservoir temperature, T: 15-80°C. | | **De Ghetto** | Light, Medium, Heavy & Extra Heavy oils | The De Getto model is a modified correlation of Egbogah & Ng. The model handles both extra-heavy oil (°API <= 10) and heavy oil (10 < °API <= 22.3). For saturated and undersaturated oil viscosity prediction, the average absolute errors were reported to be 12% and 6%, respectively. | ### **Gas Viscosity Models** | **Model** | Description | | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | |Lee
| The model is applicable within a range of reservoir temperatures, T: 100-340 °F and pressures 100-8000 psi. Average reported error is 2-4%. For high gas viscosities the model is known to under-predict the viscosity. | | **Lee modified** |The modified Lee model is reported to have an average absolute error of 2.29%. Primary difference is that Lee modified performs better for a greater range of gas viscosities.
| ## Blowout Simulation Options Number of simulations (Monte Carlo iterations) – this value can be decreased to a low number in order to check if the blowout simulation is valid. * If the blowout rates are zero after running a simulation with few iterations, the wrong PVT, Multiphase flow or oil viscosity model have been picked. Try to change model according to the descriptions above. * The number of iterations should be left at 10000 when running a full simulation. If you increase the number, the simulation time will increase significantly * All other values should (normally) be left as is