`WELTARG`

Recognised by the OPM Flow parserSCHEDULE

The WELTARG keyword modifies the target and constraints values of both rates and pressures for previously defined wells without having to define all the variables on the well control keywords: WCONPROD, WCONHIST, WCONINJE, or WCONINJH. Variables not changed by the WELTARG keyword remain the same as those previously entered via the well control keywords or previously entered WELTARG keywords. Note that the well must still be initially fully defined using the WCONPROD or WCONINJE keywords. All the aforementioned keywords are described in the SCHEDULE section.

Notes:

User Defined Quantities ("UDQ") can be used as User Defined Arguments ("UDA") for various group, well, and connection keywords in the SCHEDULE section. User Defined Arguments are activated using the UDADIMS keyword in the RUNSPEC section, and defined by the UDQ keyword in the SCHEDULE section.

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

If a well is currently a history matching well, then WELTARG should only be used to change a well's bottom-hole pressure limit, vertical flow performance table number or the artificial lift quantity.

See also the WELCNTL keyword, in the SCHEDULE section that can be used to reset the control mode, as well as a well’s target and constraints of both rates and pressures.

Records: One or more records, each terminated by /
Items per record: 3

Parameters

No.	Name	Description	Type	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 production rates and pressures data are being redefined. Note that the well name (WELNAME) must have been declared previously using the WELSPECS and WCONPROD (or WCONINJE) keywords in the SCHEDULE section, otherwise an error may occur.	STRING				None
2	`CMODE` manual: `TARGET`	A defined character string that sets the item to be changed for the well the value of the item is set by item (3). ORAT: reset the surface oil production rate value as defined by item (3). WRAT: reset the surface water production rate value as defined by item (3). GRAT: reset the surface gas production rate value as defined by item (3). LRAT: reset the surface liquid (oil plus water) production rate value as defined by (3). CRAT: reset the linearly combined calculated rate value as defined by (3). This option is not supported. RESV: reset the in situ reservoir volume rate value as defined by (3). BHP: reset the bottom-hole pressure value as defined by item (3). THP: reset the tubing head pressure value for the well as defined by item (3). VFP: reset the vertical lift performance table number as defined by (3). LIFT: reset the artificial lift quantity for use with vertical lift performance tables. GUID: reset the guide rate value for wells operating under group control. The commercial compositional simulator options: WGRA, NGL, CVAL, REIN, STRA, SATP and SATT are not applicable. Note that TARGET only defines the variable to be changed, it does not change how a well is controlled. For example, if a well is operating on ORAT control, as defined by the previously entered WCONPROD keyword, entering TARGET equal to LRAT with a value, changes the liquid constraint but the well still remains on ORAT control. Use the WELCNTL keyword in the SCHEDULE section to change the control mode of a well. `ORATWRATGRATLRATCRATRESVBHPTHPVFPLIFTGUID`	STRING				None
3	`NEW_VALUE` manual: `VALUE Liquid Gas Res Vol Pressure VFP LIFT`	A real positive value that defines the value of the variable declared by TARGET This value may be specified using a User Defined Argument (UDA).	UDA	stb/d Mscf/d rb/d psia dimensionless same as VFPPROD or VFPINJ	sm3/day sm3/day rm3/day barsa dimensionless same as VFPPROD or VFPINJ	scc/hour scc/hour rcc/hour atma dimensionless same as VFPPROD or VFPINJ	None

Example

The following example below shows the oil rates for the OP01 oil producer at the start of the schedule section (January 1, 2000).
-- ------------------------------------------------------------------------------
-- 01 JAN 2000 START OF SCHEDULE SECTION
-- ------------------------------------------------------------------------------
--
-- WELL PRODUCTION WELL CONTROLS
--
-- WELL OPEN/ CNTL OIL WAT GAS LIQ RES BHP THP VFP VFP
-- NAME SHUT MODE RATE RATE RATE RATE RATE PRES PRES TABLE ALFQ
WCONPROD
OP01 OPEN ORAT 3000 1* 1* 1* 1* 750.0 500. 9 1* /
/ DATES
01 FEB 2000 /
/
--
-- WELL PRODUCTION AND INJECTION TARGETS
--
-- WELL WELL TARGET
-- NAME TARG VALUE
WELTARG
OP01 ORAT 2000 /
/
From January 1, 2000 to February 1, 2000 well OP01 is open and is on oil rate control and has a target oil rate of 3,000 stb/d, and uses VFPPROD vertical lift table number 9 with a minimum tubing head pressure constraint of 500 psia. After February 1, 2000 the well’s oil rate is reduced to 2,000 stb/d and all the other parameters remain unchanged.

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