WellTest Wizard: Analysis Parameters
Subtopics:
This dialog box prompts you enter the parameters required to conduct an analysis.
In addition to the required inputs, it is often appropriate to modify parameters that have default values by editing them in the Parameters dialog box.
Saturations
Default values for saturations should be adjusted to reflect your reservoir conditions. These are used to calculate total compressibility, which is used in all of the analysis line calculations. For the gas fluid type, gas saturation defaults to 80%, oil saturation defaults to 0%, and water saturation defaults to 20%. For the oil fluid type, gas saturation defaults to 0%, oil saturation defaults to 80%, and water saturation defaults to 20%. For the water fluid type, gas saturation defaults to 0%, oil saturation defaults to 0%, and water saturation defaults to 100%.
Formation Compressibility
The default value for formation compressibility, cf, is calculated using the entered porosity and Hall’s correlation for consolidated sandstones, and is not suitable for all reservoirs. For example, naturally fractured, geo-pressured and coalbed methane reservoirs have higher formation compressibility. Formation compressibility affects the total compressibility, which is used in analysis line calculations.
Wellbore Radius
Wellbore radius (rw) defaults to 0.3 ft (0.0914 m) and should be changed to suit your wellbore dimensions.
Datum depth (TVD)
For minifrac pre-closure analyses, datum depth (TVD) defaults to the value specified in the wellbore schematic, if sandface pressures were calculated.