`DENSITY`

Recognised by the OPM Flow parserPROPS

DENSITY defines the oil, water and gas surface densities for the fluids for various regions in the model. The number of DENSITY vector data sets is defined by the NTPVT parameter on the TABDIMS keyword in the RUNSPEC section and the allocation of the DENSITY data sets to different grid blocks in the model is done via the PVTNUM keyword in the REGIONS section. One data set consists of one record or line which is terminated by a “/”. The surface density or gravity must be entered using either the DENSITY or GRAVITY keywords irrespective of which phases are active in the model.

Notes:

The keyword is followed by NTPVT tables as declared on the TABDIMS keyword in the RUNSPEC section.

Each table is terminated by a “/” and there is no “/” terminator for the keyword.

Note that provided the first table has been entered, subsequent tables may be defaulted, in this case the prior table is copied to the current table. See the third example for an illustration on how to use this feature.

According to the SPE SI standard181 The SI Metric System of Units and SPE Metric Standard, Adopted for Use as a Voluntary Standard by the SPE Board of Directors, June 1983, Society of Petroleum Engineers., Relative Density (γ) replaces Specific Gravity as the term used to define the ratio of the density of a known material to the density of reference material, at standard conditions of pressure and temperature. Standard conditions vary throughout the world, but for oil field units one normally uses14.7 psia and 60 oF, whereas for SI units some areas use 101.325 kPa and 15 oC.

The SI Metric System of Units and SPE Metric Standard, Adopted for Use as a Voluntary Standard by the SPE Board of Directors, June 1983, Society of Petroleum Engineers.

See also the GRAVITY keyword in the PROPS section, that can be used to enter the relative density values instead of the density numbers.

Records: Fixed number of records
Items per record: 3

Parameters

No.	Name	Description	Type	Dimension	Field	Metric	Lab	Default
1	`OIL` manual: `OILDEN`	OILDEN is a real number defining the density of the oil phase at surface conditions.	DOUBLE	Density	lb/ft3 37.457	kg/m3 600	gm/cc 0.6	Defined
2	`WATER` manual: `WATDEN`	WATDEN is a real number defining the density of the water phase at surface conditions.	DOUBLE	Density	lb/ft3 62.366	kg/m3 999.014	gm/cc 0.999014	Defined
3	`GAS` manual: `GASDEN`	GASDEN is a real number defining the density of the gas phase at surface conditions.	DOUBLE	Density	lb/ft3 0.062428	kg/m3 1.000	gm/cc 0.001	Defined

Example

The following shows the DENSITY keyword for when NTPVT on the TABDIMS keyword in the RUNSPEC section is set to one.
--
-- OIL WAT GAS
-- DENSITY DENSITY DENSITY
-- ------- ------- -------
DENSITY
39.0 62.37 0.04520 / PVT DATA REGION 1
The next example shows the DENSITY keyword for when NTPVT on the TABDIMS keyword in the RUNSPEC section is set to three.
--
-- OIL WAT GAS
-- DENSITY DENSITY DENSITY
-- ------- ------- -------
DENSITY
38.0 62.30 0.04500 / PVT DATA REGION 1
39.0 62.37 0.04520 / PVT DATA REGION 2
40.0 62.40 0.04800 / PVT DATA REGION 3
The third, and final, example shows the DENSITY keyword for when NTPVT on the TABDIMS keyword in the RUNSPEC section is set to four. Here table two defaults to table one, and table four defaults to table three.
--
-- OIL WAT GAS
-- DENSITY DENSITY DENSITY
-- ------- ------- -------
DENSITY
38.0 62.30 0.04500 / PVT DATA REGION 1
/ PVT DATA REGION 2
39.0 62.37 0.04520 / PVT DATA REGION 3
/ PVT DATA REGION 3
Again, note that there is no terminating “/” for this keyword.

Manual source: parts/chapters/subsections/8.3/DENSITY.fodt