API MPMS 12.2.2:2010 pdf download

API MPMS 12.2.2:2010 pdf download.Manual of Petroleum Measurement Standards Chapter 12- -Calculation of Petroleum Quantities Section 2- Calculation of Petroleum Quantities Using Dynamic Measurement Methods and Volumetric Correction Factors Part 2- -Measurement Tickets.
9 Correction Factors
Calculations in this publication arc based on correcting the measured volume of the merchantable liquid to its volume at base conditions. Correction factors are provided to adjust the metered volume to base conditions, to adjust for inaccuracies associated with the meter’s performance, to combine factors for ease of calculations. and to adjust for nonmerchantable quantities.
9.1 LIQUID DENSITY CORRECTION FACTORS
The liquid’s density shall be determined by appropriate technical standards or, if necessary, proper correlations or equations of state. If multiple parties are involved in the measurement, the method selected for determining the liquid’s densities shall be mutually agreed upon.
API MPMS Chapter 12.2, Part 1, Appendix B—Liquid Density Correlation, contains a list of recommended liquid versus API correlations in accordance with API’s position paper dated 1981. Where an API correlation does not currently exist, the appropriate ASTM standard has been provided to assist the user community.
Liquid density correction factors are employed to account for changes in density due to the effects of temperature and pressure upon the liquid. These correction factors are as follows:
CTL corrects for the effect of temperature on the liquid density.
CPL corrects for the effect of compressibility on the liquid density.
9.1.1 Correction for Effect of Temperature on Liquid (CTL)
If a quantity of petroleum liquid is subjected to a change in temperature, its density will decrease as the temperature rises, or increase as the temperature falls. This density change is proportional to the thermal coefficient of expansion of the liquid and temperature.
The correction factor for the effect ot temperature on the liquid’s density is called CTL. The CTL factor is a function of the liquid’s base density (RHOb) and weighted average temperature (TWA).
9.1.2 Correction for Compressibility on Liquid (CPL)
If a petroleum liquid is subjected to a change in pressure, the liquid density will increase as the pressure increases and decrease as the pressure decreases. The correction factor for the effect of compressibility on liquid density is called CPL.
The CPL factor is a function of the liquid’s compressibility factor (F). weighted average pressure (PWA), equilibrium vapor pressure of the liquid (Pc), and base pressure (Ph).
are terms to adjust for inaccuracies associated with the meter’s performance as determined at the time of proving. Unless the meter is equipped with an adjustment that alters its registration to account for the ME, an MF must be applied to the indicated volume of the meter.
MFs are used to adjust the indicated volume (MR—MR0) of a meter for inaccuracies associated with the meter’s performance as determined at the time of proving.
CMFs are meter factors that have been corrected from normal operating pressure to base pressure using the CPL that would otherwise belong on the measurement ticket. CMFs may be used in applications where the relative density, temperature, and pressure are considered to be constant throughout the measurement ticket period.
9.3 COMBINED CORRECTION FACTOR (CCF)
When multiplying a large number (for example, an IV) by a small number (for example, a correction factor) over and over again, a lowering of the precision may cur in the calculations. In addition, errors can occur in mathematical calculations due to sequencing and rounding between different machines or programs. To minimize these errors, the industry selected a method that combines correction factors in a specified sequence and maximum discrimination levels. The method for combining two or more correction factors is to first obtain a CCF by serial multiplication of the individual correction factors and rounding the CCF to a required number of decimal places.