WCONHIST

Recognised by the OPM Flow parserSCHEDULE

The WCONHIST keyword defines production rates and pressures for wells that have been declared history matching wells by the use of this keyword. History matching wells are handled differently than ordinary wells that use the WCONPROD keyword for controlling their production targets and constraints. However, the wells still need to be defined like ordinary production wells using the WELSPECS keyword in the SCHEDULE section.

Note that although wells can be allocated to a group when they are specified by the WELSPECS keyword, history matching wells cannot operate under group control. Field and group reporting is still consistent for all wells allocated to a group.

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 of records with each record terminated by a “/” and the keyword should be terminated by a “/”.

See also the WHISTCTL keyword that can be used to reset the TARGET phase, the GCONPROD and GCONINJE keywords to define a group’s production and injection targets and constraints, and the WCONPROD keyword to define a production well’s targets and constraints. All the aforementioned keywords are described in the SCHEDULE section.

Note

One can use TARGET set to RESV in the initial history matching runs to get a “reasonable” pressure match, this ensures that the total reservoir withdrawals are correct, although the individual phase withdrawals will not match. Once a reasonable pressure match is achieved for the reservoir then one can reset TARGET to the sales phase, OIL or GAS, and continue with the matching of all the phases.

In oil reservoirs some engineers prefer to use LIQ rather than OIL as the TARGET phase, although one should consider that as the water phase has no commercial value, the measurement accuracy is significantly less than the oil sales phase.

History matching wells are converted to ordinary wells by restating a well’s control mode using either the WCONPROD or WELTARG keywords in the SCHEDULE section.

Records

One or more records, each terminated by /

Items per record

12

Parameters

Example

The following example below shows the observed production rates for the OP01 oil producer for the first quarter of 2000.
-- ------------------------------------------------------------------------------
-- 01 JAN 2000 START OF SCHEDULE SECTION
-- ------------------------------------------------------------------------------
--
-- WELL HISTORICAL PRODUCTION CONTROLS
--
-- WELL OPEN/ CNTL OIL WAT GAS VFP VFP THP BHP
-- NAME SHUT MODE RATE RATE RATE TABLE ALFQ PRES PRES
WCONHIST OP01 OPEN ORAT 15.5E3 100.0 1550 10 1* 900.0 1* /
/ DATES
01 FEB 2000 /
/
--
-- WELL HISTORICAL PRODUCTION CONTROLS
--
-- WELL OPEN/ CNTL OIL WAT GAS VFP VFP THP BHP
-- NAME SHUT MODE RATE RATE RATE TABLE ALFQ PRES PRES
WCONHIST OP01 OPEN ORAT 15.2E3 150.0 1520 1* 1* 875.0 3250.0 /
/ DATES
01 MAR 2000 /
/
--
-- WELL HISTORICAL PRODUCTION CONTROLS
--
-- WELL OPEN/ CNTL OIL WAT GAS VFP VFP THP BHP
-- NAME SHUT MODE RATE RATE RATE TABLE ALFQ PRES PRES
WCONHIST OP01 OPEN ORAT 15.0E3 200.0 1500 1* 1* 850.0 1* /
/
From January 1, 2000 well OP01 is open and is on oil rate control, and produces 15,500 stb/d oil, with the observed rates of 100 stb/d of water and 15.5 MMscf/d of gas. The well uses VFPPROD vertical lift table number 10 so that OPM Flow can calculate the tubing head pressures based on the fluids produced and the calculated pressures in the simulator.
The next example illustrates how to convert OP01 from a history match well to a normal production well at the start for the forecast run at August 1, 2017 using the WELTARG keyword.
DATES
01 AUG 2017 /
/
--
-- WELL PRODUCTION AND INJECTION TARGETS
--
-- WELL WELL TARGET
-- NAME TARG VALUE
WELTARG
OP01 THP 1* /
/
Here by defaulting the bottom-hole pressure via 1* OPM Flow automatically applies the last bottom-hole pressure from the previous time step as the “constraining phase” together with the last historical rates as constraints. This ensures a smooth transition between history and prediction without having to resort to unreasonable changes to the model. This option is currently not implemented in OPM Flow but is expected to be incorporated in a future release.
| Note One can use TARGET set to RESV in the initial history matching runs to get a “reasonable” pressure match, this ensures that the total reservoir withdrawals are correct, although the individual phase withdrawals will not match. Once a reasonable pressure match is achieved for the reservoir then one can reset TARGET to the sales phase, OIL or GAS, and continue with the matching of all the phases. In oil reservoirs some engineers prefer to use LIQ rather than OIL as the TARGET phase, although one should consider that as the water phase has no commercial value, the measurement accuracy is significantly less than the oil sales phase. |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

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