API MPMS 12.3-2006 pdf download.Manual of Petroleum Measurement Standards Chapter 12- Calculation of Petroleum Quantities Section 3- Volumetric Shrinkage Resulting From Blending Light Hydrocarbons With Crude Oils .
6 Precautions Use the New MPMS Chapter 1 2.3 and Tables 6.1 EFFECT OF TEMPERATURE AND PRESSURE ON VOLUMETRIC SHRINKAGE The new correlation is based on experimental data gathered at conditions of absolute pressure in the range of 100-700 kilopascals, 15-115 pounds per square inch absolute, and temperatures near or Thus, it is recommended that all shrinkage calculations be limited to conditions within that range. 6.2 DIFFERENCE BETWEEN CUSTOMARY AND METRIC TABLES Shrinkage factors obtained from Table 3 in customary units will not necessarily be nu- merically equivalent to factors determined from Tables 4 and 5 in SI units. This difference is partially the result of the difference in standard temperatures versus but even after volume correction using the API correlation, shrinkage factors may show a rel- ative difference of as much as 0.4 percent. For custody transfer purposes, it is therefore rec- ommended that buyers and sellers agree on which set of tables they will use. 6.3 AND ALTERNATIVES The correlation equation or tables given in this text can predict volumetric shrinkage within the stated precision for mixtures of hydrocarbons over a relatively wide range in density difference and mixture ratios. However, the available experimental data suggest factors other than density difference affect the volumetric behavior. Current under- standing is insufficient to allow accurate prediction of the effect of composition, and thus experimental confirmation is recommended for hydrocarbon types not represented existing data sets. It is when an accurate shrinkage is required for spe- cific mixtures or when there are extenuating may make use of the shrink- age tables questionable, the shrinkage may be determined by testing the individual components in a qualified lab using one of the test methods included in Appendix C.
7 Precision Statement The new correlation equation presented in this report predicts mixture volumes within ±0.04 percent of the experimental values for 75 percent data over the en- tire range of blend ratios. Correlation of volumetric shrinkage with density difference is dependent on the accuracy of determination of the fluid densities. Other factors not included in this correlation, par- ticularly compositional uniqueness, will affect the reliability of the predicted shrinkage value. The values of percent total shrinkage presented in Tables 3 and 5 are given with four digits after the decimal. Note prediction and measurement two digit resolution at most (XX.XX percent shrinkage). The additional digits are for convenience in calculations involving custody transfer quantities. If the correlation is being used to correct values for a fluid balance determination, one should note that the predicted shrinkage is technically defensible to two digits. 8 Shrinkage Tables The following tables are the standard for calculation of volumetric shrinkage. (See ex- amples in 5.4.) a. Volumetric Shrinkage Percentage Factors for Blending Two Hydrocarbons with Gravity Differences from and from 1 to 99 percent Light Hydrocarbon Component in Total Blend (Table 3) This table is entered with the difference in API gravity between the light and heavy hy- drocarbon components and the percentage by volume of the light hydrocarbon in the mix to obtain a percentage shrinkage of the total volume of the mixture. Multiplication of the percentage factor extracted from the table (divided by 100) by the total volume of the mix- ture equals the volumetric occurs from mixing the light with the heavy hy- drocarbon component.
c. Volumetric Shrinkage Percentage Factors for Blending Two Hydrocarbons with Differ- ences in Inverse Densities at in m3/kg Determined from Table 4 and from 1to99 Per- cent Light Hydrocarbon Component in Total Blend (Table 5-Metric) This table is entered between inverse densities of the light and heavy components (from Table 4) and the percentage light component in the total mix to deter- mine a percentage shrinkage of the total volume of the mixture. Multiplication of the per- centage factor extracted from the table (divided by 100) by the total volume of the mixture equals the volume shrinkage that occurs from mixing the light with the heavy hydrocarbon component.