`WELSPECL`

Recognised by the OPM Flow parserSCHEDULE

The WELSPECL keyword defines the general well specification data for all well types and must be used for all wells contained within a Local Grid Refinement (“LGR”) instead of the WELSPECS keyword. WELSPECL must declare wells first before any other LGR well specification keywords are used in the input file. The keyword declares the name of well, the group the well belongs to, the LGR the well is incorporated into, the wellhead location and other key parameters.

This keyword is not supported by OPM Flow but would change the results if supported so the simulation will be stopped.

Notes:

The keyword is followed by any number of records with each record terminated by a “/” and the keyword should be terminated by a “/”.

Note that the total number of individual wells declared by the WELSPECS cannot exceed the valued entered via the MXWELS variable on the WELLDIMS keyword in the RUNSPEC section.

See also the COMPDATL keyword to define a well’s connections in a LGR, the WCONPROD and WCONINJE keywords to define a well’s production and injections targets and constraints. All the aforementioned keywords are described in the SCHEDULE section.

Records: One or more records, each terminated by /
Items per record: 18

Parameters

No.	Name	Description	Type	Dimension	Field	Metric	Lab	Default
1	`WELL` manual: `WELNAME`	A character string of up to eight characters in length that defines the well name for which the well specification data is being defined.	STRING					None
2	`GROUP` manual: `GRPNAME`	A character string of up to eight characters in length that defines the group name for which the well is assigned to. The group named FIELD is the top most group and thus GRPNAME cannot be set to FIELD, although this is allowed in the commercial compositional simulator but not the commercial black-oil simulator. Note that the group hierarchy should be defined by the GRUPTREE keyword when there is more than one level of groups, otherwise all the groups will sit directly under the FIELD group in the group tree hierarchy. Secondly, groups defined by the GRUPTREE keyword cannot contain other groups and wells; that is, groups must either contain other groups or wells but not both. If necessary, wells can be re-allocated to a different group by re-entering a well's WELSPECS data together with a new value for GRPNAME.	STRING					None
3	`LGR` manual: `LGRNAME`	A character string of up to eight characters in length that defines the name of the local grid refinement for which the well is assigned to.	STRING					None
4	`HEAD_I` manual: `I`	A positive integer greater than or equal to zero and less than or equal to NX on the CARFIN keyword for Cartesian grids, that defines the wellhead location for a vertical or deviated well, or the heel for a horizontal well in the I-direction within the LGR. For radial LGRs this parameter should be set to one.	INT					None
5	`HEAD_J` manual: `J`	A positive integer greater than or equal to zero and less than or equal to NY on the CARFIN keyword for Cartesian grids, that defines the wellhead location for a vertical or deviated well, or the heel for a horizontal well in the J-direction within the LGR. For radial LGRs this parameter should be set to one.	INT					None
6	`REF_DEPTH` manual: `BHPREF`	A real value that defines the reference depth for reporting the bottom-hole pressure for the well. Ideally this value should be set to the midpoint of the perforations as defined by the COMPDATL keyword in the SCHEDULE section. If defaulted by 1* or set to a value less than or equal to zero, then the mid-point of shallowest connection defined by the COMPDATL keyword will be used.	DOUBLE	Length	feet	m	cm	Mid-point of shallowest connection defined by the COMPDATL keyword
7	`PHASE` manual: `TYPE`	A defined character that defines the “main” phase for the well, and should be set to one of the following character strings: GAS: for a gas well. OIL: for an oil well. WAT: for a water injection well. LIQ: for an oil well when the liquid productivity index is required for the well. This parameter defines the phase used to calculate a well’s productivity or injectivity index and the type of well, or a well’s connection, to close when a group’s production constraints, as defined on the GCONPROD keyword in the SCHEDULE section, have been violated. For example, if the well is declared as an oil well, then excessive gas and water connections will be subject to closure. `GASOILWATLIQ`	STRING					None
8	`D_RADIUS` manual: `DRADIUS`	A real value that defines the well drainage radius for the well used to calculate a well’s productivity or injectivity index. A default of zero results in the pressure equivalent radius of the grid blocks containing the well connections are used.	DOUBLE	Length	feet	m	cm	0.0
9	`INFLOW_EQ` manual: `INFLOW`	A defined character string that defines the inflow equation to be used for the well in calculating the well’s flow rates. INFLOW should be set to one of the following character strings: STD: the standard inflow equation will be used. This is normally used for wells that are primary oil or water wells. NO: an alias for STD. R-G: the Russell Goodrich1 Russell, D.G., Goodrich, J.H., Perry, G.E and Bruskotter, J.F "Methods of Predicting Gas Well Performance", Transactions of the ASME, Journal of Petroleum Technology (1966) 99-108. pressure square inflow equation will used. This option can be used for dry gas wells. Russell, D.G., Goodrich, J.H., Perry, G.E and Bruskotter, J.F "Methods of Predicting Gas Well Performance", Transactions of the ASME, Journal of Petroleum Technology (1966) 99-108. YES: an alias for R-G. P-P: the general dry gas pseudo pressure inflow equation will be used. Normally used for dry gas wells. GPP: the generalized gas pseudo pressure inflow equation used with wet gas wells, that is condensate gas wells. This inflow equation is based on the formulation of Whitson et al.2 Whitson, C. H. and Fevang, Ø. “Generalised Pseudopressure Well Treatment in Reservoir Simulation,” Presented at the IBC Technical Services Conference on Optimisation of Gas Condensate Fields, Aberdeen, UK (June 26-27, 1997). Whitson, C. H. and Fevang, Ø. “Generalised Pseudopressure Well Treatment in Reservoir Simulation,” Presented at the IBC Technical Services Conference on Optimisation of Gas Condensate Fields, Aberdeen, UK (June 26-27, 1997). For oil and water wells the INFLOW should be set to STD, why for dry gas wells INFLOW can be set to either R-G or P-P; however, the P-P option is preferred for dry gas wells due to the more rigorous treatment of gas flow. For wet gas wells, that is gas condensate wells, INFLOW should be set to GPP. Only INFLOW equal to STD and NO are currently implemented in OPM Flow. `STDNOYESGPP`	STRING					STD
10	`AUTO_SHUTIN` manual: `AUTO`	A defined character string that defines the automatic action to be taken if the economic WCUT, GOR, or WGR limits are violated and the well is to cease production. AUTO should be set to one of the following character strings: STOP: the well is “stopped” at the surface and will not produce any fluids to surface; however, if there any open connections then flow may occur within the wellbore and between the open connections depending on a connection’s potential with respect to all the other connections. Inter-connection flow (cross flow) can be prevented by setting the XFLOW variable to NO. In this case the well’s behavior will be similar to the SHUT option described below. SHUT: the well is shut at the surface and downhole, this results in no flow at the surface and no cross flow downhole. The corrective action takes places at the end of the time step in which the constraint is violated. `STOPSHUT`	STRING					SHUT
11	`CROSSFLOW` manual: `XFLOW`	A defined character string that defines the if cross flow should occur within the wellbore, and should be set to either: YES: to allow cross flow in the wellbore through well connections. NO: to disallow cross flow within the wellbore, even if the flow potentials in the well connections would allow such flow to occur. In some cases numerical issues can occur if this variable is set to YES, and resetting it to NO may resolve the issue; however the results may not represent the physical process in this case. `YESNO`	STRING					YES
12	`P_TABLE` manual: `PVTNUM`	A positive integer greater than or equal to zero that defines the PVT table used to calculate the wellbore fluid properties that define the relationship between reservoir and surface volume rates. The default value of zero sets PVTNUM to be the PVT table of the deepest connection in the well.	INT					0
13	`DENSITY_CALC` manual: `DENOPT`	A defined character string that sets the type of density calculation used in calculating the wellbore hydrostatic head, and should be set to one of the following character strings: SEG: sets the hydrostatic head density calculation to segmented. In this cases the density is calculated between neighboring well connections and the volumes flowing from the connections. This is the more accurate calculation if the fluid properties flowing from the well connections are variable. The density calculation itself is explicit, i.e. uses the flowing volumes of the last time step. AVG: sets the hydrostatic head density calculation to the average density calculation. Here the density is considered uniform across a given reservoir and is dependent on total inflow rates of each phase and the well’s bottom-hole pressure The default option of 1* invokes the SEG option and is the only option implemented in OPM Flow. `SEGAVG`	STRING					SEG
14	`FIP_REGION` manual: `FIPNUM`	An integer value defines the FIPNUM region used to determine the reservoir conditions in calculating the well’s reservoir volumes. If set to a negative integer value then the FIPNUM region of the deepest connection in the well will be used. If set to zero, the default value, then the average properties for the field will be used. If set to an integer value greater than zero, then the FIPNUM indicated by this value will be used.	INT					0
15	`FRONTSIM1`	Not used.	STRING
16	`FRONTSIM2`	Not used.	STRING
17	`well_model`	Not used.	STRING
18	`POLYMER_TABLE`	Not used.	INT

Example

The following example defines three wells using the WELSPECL keyword
--
-- WELL SPECIFICATION DATA FOR LGR WELLS
--
-- WELL GROUP LGR LOCATION BHP PHASE DRAIN INFLOW SHUT CROSS PVT
-- NAME NAME NAME I J DEPTH FLUID AREA EQUA. IN FLOW TABLE
WELSPECL
GI01 PLATFORM LGR01 14 13 1* GAS 1* P-P SHUT NO 1* /
GP01 PLATFORM LGR01 64 80 1* GAS 1* GPP SHUT NO 1* /
OP01 PLATFORM LGR02 24 10 1* OIL 1* STD SHUT NO 1* /
/
Here, well GI01 and GP01 are in the same LGR named LGR01 and OP01 is in a separate LGR named LGR02. GI01 is a dry gas injection well that uses the dry gas pseudo inflow equation, GP01 is a gas condensate well that uses the generalized gas pseudo pressure inflow equation, and finally, OP01 is an oil well that uses the standard inflow equation. All wells: will be shut if they are required to cease production, all wells disallow cross flow, and the hydrostatic head calculation is defaulted to the segment option for all wells.

Manual source: parts/chapters/subsections/12.3/WELSPECL.fodt