API RP 85-2003 pdf download.Use of Subsea Wet-gas Flowmeters in Allocation Measurement Systems.
2 Referenced Publications API RP 17A Design and Operation of Subsea Produc- tion Systems Manual of Petroleum Measurement Standards (MPMS), Chapter 20 ÒAllocation MeasurementÓ ISO 1 Guide to the Expression of Uncertainty in Measurement Basil, M. and A.W. Jamieson, Uncertainty of Complex Sys- tems Using the Monte Carlo Techniques, North Sea Flow Measurement Workshop, Gleneagles, Scotland, October 1998. 3 Definitions and Nomenclature 3.1 DEFINITIONS 3.1.1 allocation: The (mathematical) process of assign- ing portions of a commingled production stream to the sources, typically wells, which contributed to the total ßow. 3.1.2 allocation meter: A ßow measurement device used for the speciÞc purpose of measuring the ßow rates from a single well or input ßowline; not to be confused with the ref- erence meter. 3.1.3 commingle: To combine the hydrocarbon streams from two or more wells or production facilities into common tanks or pipelines. 3.1.4 Equations of State (EOS): Equations which relate the compositions, pressures, temperatures, and various other physical properties of gases and liquids to one another, and are used to predict the transformation of physical state when conditions change (see PVT Analysis).
3.1.5 error: The difference between the result of a mea- surement and the true value of the measurand. 3.1.6 estimate: A measurement which has been corrected to remove the effects of inßuence factors. 3.1.7 gas-oil ratio (GOR): The ratio of produced gas ßow rate to the liquid hydrocarbon ßow rate at any point, measured in standard cubic feet per barrel (SCF/BBL) or standard cubic meters of gas per cubic meter of liquid hydro- carbon (m 3 / m 3 ). 3.1.8 gas (liquid) volume fraction, GVF (LVF): The fraction of the total volumetric ßow at actual conditions in the pipe which is attributable to gas (liquid) ßow. 3.1.9 imbalance upper/lower control limit: A limit on System Balance that is established for the purpose of main- taining control of the overall process. 3.1.10 individual allocated quantity ( A i ): A contribut- ing meterÕs share of the master quantity ( Q z ) that incorporates a calculated share of the system imbalance ( I ), so that the sum of all the allocated quantities ( S A i ) equals the master quantity ( Q z ). 3.1.11 individual quantity ( IQ i ): The quantity deter- mined by an individual contributing meter or measurement point. 3.1.12 individual theoretical quantity ( Q i ): The quan- tity represented by an individual contributing meter or mea- surement point after conversion to a theoretical value by applying an Equation of State (EOS) or other correction fac- tor, usually done in order to adjust the measured quantity for comparison at the same pressure and temperature base as the Master Quantity ( Q Z ). 3.1.13 influence factor: A quantity which is not the measurand, but which will affect the result of measurement.
3.1.19 pressure-volume-temperature (PVT) rela- tionship: Application of Equations of State (EOS) to a com- posite ßuid to calculate the change in properties in going from one set of conditions (P and T) to another. 3.1.20 random error: The error which deviates about the mean value of the measurement in an unpredictable, bipolar fashion. 3.1.21 reference meter: A ßow meter used for the spe- ciÞc purpose of measuring the ßow rates of one phase of the commingled stream, (e.g., the liquid hydrocarbon ßow rate). 3.1.22 repeatability: The closeness of the agreement between results of successive measurements of the same mea- surand carried out under the same conditions of measurement. 3.1.23 reproducibility: The closeness of agreement of measurement results of the same measurand carried out under changed conditions of measurement, such as different loca- tion, time, reference standard, etc. 3.1.24 sample (experimenta