C023 – API Density Referral 1980-86
Description
This converts density values between standard conditions (1.01325 bar and 15°C) and other observed or line conditions.
References
The correction for temperature is calculated using the Manual of Petroleum Measurement Standards Chapter 11.1 – Volume correction factors Volume 10 – Background, Development and Program Documentation: API Standard 2540 First Edition August 1980.
Measurement of Petroleum Measurement Standards Chapter 11.2.1 – Compressibility Factors for Hydrocarbons: 0-90° API Gravity Range (1984)
Measurement of Petroleum Measurement Standards Chapter 11.2.1M – Compressibility Factors for Hydrocarbons: 638-1074 Kilograms per Cubic Metre Range (First Edition August 1984)
Measurement of Petroleum Measurement Standards Chapter 11.2.2 – Compressibility Factors for Hydrocarbons: 0.350-0.637 Relative Density (60°F/60°F) and -50°F to 140°F Metering Temperature (First Edition October 1986)
Measurement of Petroleum Measurement Standards Chapter 11.2.2M – Compressibility Factors for Hydrocarbons: 350-637 Kilograms per Cubic Metre Density (15°C) and -46°C to 60°C Metering Temperature (First Edition October 1986)
Kelton calculation reference C023
FLOCALC calculation reference F023
KIMS calculation reference K212
Options
Solve for
The standard density calculation methods (with the exception of User entered RD) are bi directional
- Standard density
Calculate the standard density from the density at a given pressure and temperature
- Density
Calculate the density at a given pressure and temperature from the standard density
Precision
The precision options enables switching between rounding methods
- Full
This enables you to bypass the rounding methods outlined in the algorithms and use the full precision during the calculation
- Rounding
Select this option to follow the algorithms to the same rounding precision as is in the standard
Calculation
The temperature correction factor, Ctl, is calculated using the procedure in C222.
The pressure correction factor, Cpl, is calculated using the procedure in C220.
Density
When solving for density the temperature correction according to API 11.1 is applied followed by the pressure correction according to API MPMS Chapter 11.2.1.
Standard Density
When solving for standard density an iterative calculation is performed making use of the API 11.1 and API MPMS Chapter 11.2.1 algorithms. An initial estimate is taken for standard density based upon the entered density. This value is then fed into the API 11.1 temperature correction algorithm to gain the Ctl. The estimate for standard density is then taken into the API 11.2.1 pressure correction algorithm to gain the Cpl. The Ctl and Cpl are then fed into the below formula to gain a new estimate of standard density. The process is repeated until standard density values converge to within 10-6.
