WDFAC
Recognised by the OPM Flow parserSCHEDULE
The WDFAC keyword defines a gas well’s D-factor (flow dependent skin factor), which is normally derived from well tests or calculated analytically based on the coefficient of inertial resistance, usually known as β, in Forchheimer’s flow equation,1 Geertsma, J., 1974. Estimating the Coefficient of Inertial Resistance in Fluid Flow Through Porous Media. Soc.Pet.Eng.J., October: 445-450., 2 Gewers, C.W.W. and Nichol, L.R., 1969. Gas Turbulence Factor in a Microvugular Carbonate. J.Can.Pet.Tech., April.and 3 Wong, S.W., 1970. Effects of Liquid Saturation on Turbulence Factors for Gas Liquid Systems. J.Can.Pet.Tech., October.
Geertsma, J., 1974. Estimating the Coefficient of Inertial Resistance in Fluid Flow Through Porous Media. Soc.Pet.Eng.J., October: 445-450.
Gewers, C.W.W. and Nichol, L.R., 1969. Gas Turbulence Factor in a Microvugular Carbonate. J.Can.Pet.Tech., April.
Wong, S.W., 1970. Effects of Liquid Saturation on Turbulence Factors for Gas Liquid Systems. J.Can.Pet.Tech., October
Internally the simulator evaluates a D-factor for each well connection by assuming the D-factors are inversely proportional to the connection transmissibility factors. This is done at the time the well D-factor is specified. If a connection is later closed then the well D-factor is likely to change but the connection D-factors for each of the remaining open connections should not be affected.
Notes:
The keyword is followed by any number of records with each record terminated by a “/” and the keyword should be terminated by a “/”.
See also the WDFACCOR keyword in the SCHEDULE section that uses Dake’s4 Dake, L.P. Fundamentals of Reservoir Engineering, Amsterdam, The Netherlands, Elsevier Science BV (1978) Chapter 8.6, pages 252-257. correlation to calculate the well D-factor; and the COMPDAT keyword in the SCHEDULE section that can be used to specify the connection D-factors directly.
Dake, L.P. Fundamentals of Reservoir Engineering, Amsterdam, The Netherlands, Elsevier Science BV (1978) Chapter 8.6, pages 252-257.
- Records
- One or more records, each terminated by
/ - Items per record
- 2
Parameters
| No. | Name | Description | Type | Dimension | Field | Metric | Lab | Default |
|---|---|---|---|---|---|---|---|---|
| 1 | WELLmanual: WELNAME | A character string of up to eight characters in length that defines the well name for which the well D-factor is being defined. Note that the well name (WELNAME) must have been declared previously using the WELSPECS keyword in the SCHEDULE section. | STRING | None | ||||
| 2 | DFACTOR | A real positive value greater than or equal to zero that defines the D-factor for the well. | DOUBLE | Time/ | day/ | day/ | hour/ | 0.0 |
Example
--
-- WELL D-FACTORS
--
-- WELL D-
-- NAME FACTOR
WEFAC
GP01 1.0E-03 /
/
In the above example a well D-factor of 10-3 is specified for gas well GP01.Manual source: parts/chapters/subsections/12.3/WDFAC.fodt