Properties Tab

Subtopics:

Property Type View

Reservoir Properties View

Inputs Pane

Toolbar Icons

Gas Properties

Additional Properties for Liquid-rich Gas

Oil / Condensate Properties

Water Properties

CBM Properties

Adsorption Properties

Geomechanical Properties

Capillary Pressure Properties

Relative Permeability Properties

Main View

Property Type View

In this view, you can select the property type. When you click to select a property type, the Inputs pane updates to show the available inputs and calculated parameters specific to that property type, and the Main View updates to show the appropriate correlations in plot or tabular format.

An exclamation mark beside a property type indicates that the properties have not been fully specified. In the screenshot below, Oil has an exclamation mark beside it. This is only a problem if your reservoir has oil. If this is the case, click Oil and enter the required parameters.

The Property Type view also has a toolbar where you can change your plotting options, import custom data, and copy / paste data.

Reservoir Properties View

This view includes inputs for standard reservoir properties. Some of these parameters, such as reservoir temperature, are required in order to display data on the plots or tables in the Main view.

Inputs Pane

The Inputs pane is to the right of the Properties pane. This pane shows the available correlations, input parameters, and calculated values specific to the property type selected in the Property Type view. The inputs can change when the correlation changes.

Toolbar Icons

The toolbar icons for this pane are as follows:

View Data — view your data in the Main view in a table format. This icon is only displayed when the Main view is displaying plots.
View Plot — view your data in the Main view represented by plots. This icon is only displayed when the Main view is displaying tables.
Import Data — bring in your custom property data.
Help for Correlations — after clicking this icon, select either PVT Correlation Help, or Viscosity Correlation Help. A dialog box opens, which displays information about each of the available correlations. This icon is disabled for property types that don't have correlations.
Change Bottom Left Plot — while viewing your plots, there may be an additional plot that can be viewed by clicking this icon. This icon is only displayed when more than four plots are available. For example, when liquid-rich gas is selected, there is an additional plot to view the vaporized oil ratio.

Gas Properties

This view displays drop-down lists where you can select the PVT correlation (for Z, B_g, and c_g) and viscosity correlation.

Note:

Unless otherwise noted, all percentages are in mole %.

From the Gas Type drop-down list, you can select one of the following gas types: dry gas, wet gas, or liquid-rich gas. When liquid-rich gas is selected, an additional drop-down list and gas property inputs is displayed. The Vaporized Oil Ratio (Rs) Correlation drop-down list is used to model liquid drop-out in the Gas Condensate Numerical models. To calculate a recombined gas rate factor and a recombined gas gravity (used in analytical modeling of gas condensate reservoirs), enter the initial condensate gas ratio (CGR), condensate gravity, and separator temperature and pressure to be used with gas gravity. For additional information, see Gas Condensate Properties.

After you select Gas in the selection tree, you can select a PVT correlation or custom table from the PVT Correlation drop-down list. (If you select Custom Table, you can enter your own data.) In the Viscosity Correlation drop-down list, you can select a viscosity correlation or a custom table. In the Gas Type drop-down list, you can select dry gas, wet gas, or liquid-rich gas. These selections affect how gas properties are calculated.

Gas Properties, Gas Composition, and Critical Properties can be entered as input parameters in each of their sections. The calculated properties at p_i and T_R are also displayed.

Gas properties vs pressure are plotted, including Z, ψ, B_g or B_gd, ρ_g, c_g, R_v, V_L / V_sat, and μ_g.

Additional Properties for Liquid-rich Gas

If the Gas Type is set to Liquid-Rich Gas, additional properties are displayed:

Vaporized Oil Ratio Correlation — defines the amount of liquid vaporized in gas as a function of pressure.
p_dew — dew point pressure. It should be set to the same value as the bubble point pressure defined under Oil / Condensate properties.
CGR_I — condensate gas ratio at the separator.
γ_cond — condensate gravity. It should be set to the same value as the oil gravity defined under Oil / Condensate properties.
T_sep, p_sep — temperature and pressure at the separator.
RGRF — recombined gas rate factor. We recommend keeping the default value.
G_r — recombined gas gravity. All gas property functions are generated based on this gas gravity (as well as critical temperature and pressure).

Oil / Condensate Properties

This view displays drop-down lists where you can select the PVT correlation (for R_so, B_o, and c_o) and viscosity correlation.

If the available correlations do not describe your oil properties satisfactorily, you can select custom correlations, and import or paste custom PVT data into tables for R_s, B_o, and mu. Alternatively, you can calibrate a correlation to shift it through a known PVT point by populating the inputs in the Calibration Properties section of the Oil Inputs pane. When calibrating an oil correlation, check all the plots to ensure that the resulting properties make sense. For example, if unrealistic values are entered for R_so and B_o, the oil compressibility curve, which is calculated from the R_so and B_o curves, may contain discontinuities. See Oil Calibration for more information.

After you select Oil / Condensate in the selection tree, you can select a PVT correlation, constant properties, or custom table from the PVT Correlation drop-down list. In the Viscosity Correlation drop-down list, you can select a correlation, constant properties, or custom table.

Oil properties can be entered as input parameters. The calculated properties at p_i and T_R are also displayed. Calibration properties can be entered to calibrate your oil / condensate properties.

Oil properties vs pressure are plotted, including R_so, B_o, ρ_o, c_o, and μ_o.

Water Properties

This view displays a drop-down list and fields where you can enter your water properties.

After you select Water in the selection tree, you can select a correlation, constant properties, or custom table from the General Correlation drop-down list.

You can enter Water Composition as input parameters, and you can select the Gas Saturated checkbox to take into account gas saturation in water. The calculated properties at p_i and T_R are displayed.

Water properties vs pressure are plotted, including R_sw, B_w, ρ_w, c_w, and μ_w.

CBM Properties

WellTest supports coalbed methane (CBM) analytical models (appropriate for dry CBM wells) and numerical models (for wet or dry CBM wells). The pseudo-steady state (PSS) models, designed to model wet CBM wells analytically, are available in IHS Harmony^TM, but not in WellTest. The Initial Gas Composition section of the CBM Inputs pane only impacts the PSS models and has no impact on WellTest.

Enter the Langmuir Isotherm and Coal properties to account for the gas adsorbed on the coal.

After you select CBM in the selection tree, Initial Gas Composition, Langmuir Isotherm, and Coal Properties can be entered as input parameters. In the Matrix Shrinkage Correlation drop-down list, you can select a correlation or custom table.

CBM properties vs pressure are plotted, including Gas Content, k / k_i, and Φ / Φ_i.

Adsorption Properties

Adsorption properties should be entered to account for adsorbed gas in shales. For adsorption in CBM reservoirs, the CBM properties should be populated.

After you select Adsorption in the selection tree, Langmuir Isotherm, and Shale Properties can be entered as input parameters.

Gas content vs pressure is plotted.

Geomechanical Properties

With geomechanical properties, you can model pressure-dependent permeability and formation compressibility, which are significant in over-pressured reservoirs such as the Haynesville shale.

After you select Geomechanical in the selection tree, you can select a correlation or custom table from the Permeability Ratio Correlation drop-down list. In the Compressibility Ratio Correlation drop-down list, you can select a correlation or custom table.

Geomechanical properties vs pressure are plotted, including k / k_i and c_f / c_fi.

Capillary Pressure Properties

Capillary pressure properties are used by numerical models.

After you select Capillary Pressure in the selection tree, you can select a correlation or custom table from the Capillary Pressure Correlation drop-down list.

Capillary pressures vs pressure are plotted, including p_cgo, p_cgw and p_cow.

Relative Permeability Properties

Relative permeability properties are used by numerical models.

After you select Relative Permeability in the selection tree, you can select a correlation or custom table in the 2-Phase Model Correlation drop-down list. You can enter input parameters for water-gas, oil-gas, and water-oil. In the 3-Phase Model Correlation drop-down list, you can select a correlation.

Relative permeabilities vs pressure are plotted for gas-water, gas-oil, and oil-water. The 3-phase relative permeability is also presented in a triangle graph.

Main View

This view consists of plots or tables displaying how properties vary with pressure or saturation, and depends on the property type selected in the Property Type view. To switch between viewing plots or tables, click the View Data or View Plot icons on the toolbar of the Inputs pane.

Note:

The tables are read-only unless a Custom correlation is selected in the Inputs pane.