Unconventional Reservoir Parameters
The parameters include the inputs you specify, or the default Harmony values and calculated values from the plot interpretations.
The raw data derivative and the beta-derivative can be displayed in the typecurve plot by clicking the checkboxes in Typecurve Options (see screenshot below). For bilinear flow, the beta-derivative is 0.25; for linear flow, it is 0.5; for boundary-dominated flow, it is 1.0.
Additional gas options for adsorption and geomechanical models can be used by clicking their checkboxes (see screenshot below). These model options require that the Langmuir isotherm and permeability and/or compressibility ratio correlations are entered in the Properties Editor.
The flowing pressure inputs in the Forecast parameters section are used with the
slope of the square-root time plot to determine xf√k.
You can enter the drainage area, or area of SRV
, but by default, these values come from the
OOIP / OGIP on the flowing material balance (FMB) plot. Changes to
the OOIP / OGIP on the FMB will update the area. The
decline exponent, b, and final gas rate are used to calculate the hyperbolic
decline forecast. The start date is the end of production data for the
well. The ∆t is set based on the forecast duration to reach the final
rate, and corresponds to the end date. Either qf
or ∆t can be entered, and the other value will be calculated.
The second half of the parameters section displays calculated values from the interpretations. The xf√k is displayed from the square-root time plot, and can be used to determine xf if the matrix permeability is entered. The time to reach the end of linear flow (telf) is determined from the slope of the square-root time plot, the flowing pressure, and the drainage area entered or determined from OOIP / OGIP. The OOIP / OGIP displayed is related to the area used. The expected ultimate recovery (EUR), remaining recoverable (RR), and recovery factor (RF) come from the boundary-dominated flow forecast.
