1 Scope
This standard specifies the calculation methods of static liquid quantities of crude oil, petroleum products and petrochemical products (hereinafter referred to as oil products) in oil storage containers, defines the terms employed in the calculation of static oil quantities, and gives the equations for calculating some correction factors. Fundamental to this process is that different users can obtain consistent results through calculation by using the same basic data (tank capacity table, levels, densities, temperatures, etc.) regardless of whether the data is gathered automatically or manually.
This standard is applicable to calculation of quantities of oil products, at atmospheric conditions, in upright cylindrical tanks, oil tankers, railway tankers, horizontal cylindrical tanks, road tankers and other oil storage containers.
This standard does not address the calculation of oil quantities for clingage, non-liquid material, small quantities remaining on board, and oil vapor space.
The reference conditions for calculating static oil quantities in this standard are: standard temperature of 20°C and atmospheric pressure of 101.325 kPa.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 260 Determination of Water Content in Petroleum Products
GB/T 1884 Crude Petroleum and Liquid Petroleum Products—Laboratory Determination of Density—Hydrometer Method (GB/T 1884-2000, eqv ISO 3675:1998)
GB/T 1885 Petroleum Measurement Tables (GB/T 1885-1998, eqv ISO 91-2)
GB/T 4756 Petroleum Liquids—Manual Sampling (GB/T 4756-1998, eqv ISO 3170:1988)
GB/T 6531 Crude Petroleum and Fuel Oils—Determination of Sediment—Extraction Method (GB/T 6531-1986, eqv ISO 3735:1975)
GB/T 6533 Test Method for Water and Sediment in Crude Oil by the Centrifuge Method (eqv ASTM D4007:1981)
GB/T 8170 Rules for Rounding Off of Numerical Values
GB/T 8927 Petroleum and Liquid Petroleum Products—Method of Measuring the Temperature
GB/T 8929 Crude Petroleum—Determination of Water—Distillation Method (eqv ASTM D4006:1981)
GB/T 13235.1 Petroleum and Liquid Petroleum Products—Volumetric Calibration of Vertical Cylindrical Metal Tanks—Strapping Method (GB/T 13235.1-1991, neq ISO/DIS 7507-1)
GB/T 13235.2 Petroleum and Liquid Petroleum Products—Volumetric Calibration of Vertical Cylindrical Metal Tanks—Optical Reference Line Method (neq ASTM D4738:1990)
GB/T 13235.3 Petroleum and Liquid Petroleum Products—Volumetric Calibration of Vertical Cylindrical Metal Tanks—Electro-optical Distance-ranging Internal Method (GB/T 13235.3-1995, neq ISO/DIS 7507-4)
GB/T 13377 Crude Petroleum and Liquid or Solid Petroleum Products—Determination of Density or Relative Density—Capillary Stoppered Pyknometer and Graduated Bicapillary Pyknometer Methods (GB/T 13377-1992, neq ISO 3838:1983)
GB/T 13894 Petroleum and Liquid Petroleum Products—Measurement of Liquid Level in Tank—Manual Method (neq API 2545-65:1987)
GB/T 17605 Petroleum and Liquid Petroleum Products—Volumetric Calibration of Horizontal Cylindrical Metal Tanks (Manual Methods) (neq API 2551:1997)
GB/T 18273 Petroleum and Liquid Petroleum Products—Direct Static Measurements—Contents of Vertical Storage Tanks—Mass Measurement by Hydrostatic Tank Gauging (GB/T 18273-2000, eqv ISO 11223-1:1995)
JJG 133 Road Tankers Capacity
JJG 140 Volume of Rail Tankers
JJG 168 Vertical Metal Tank Capacity
JJG 266 Horizontal Metal Tank Capacity
JJG 702 Verification Regulation of Ships Liquid Cargo Tank Capacity
SH/T 0604 Crude Petroleum and Petroleum Products—Determination of Density—Oscillating U-tube Method (SH/T 0604-2000, eqv ISO 12185:1996)
ISO/TR 8338 Crude Petroleum Oil—Transfer Accountability—Method for Estimation on Ships of Total Quantity Remaining on Board (ROB)
ISO 3171 Petroleum Liquids—Automatic Pipeline Sampling
API MPMS Chapter 2 Tank Calibration
API MPMS Chapter 17 Marine Measurement
3 Terms and Definitions
For the purposes of this standard, the following terms and definitions apply. Refer to Appendix B for the comparison of symbols of terms at home and abroad.
3.1
Free water (FW)
Water that is separated in oil products and mainly exists under oil products. VFW represents the deduction of free water, including bottom sediments.
3.2
Sediment and water (SW)
Generic term for suspended sediment, dissolved water and suspended water in oil products, of which the mass fraction or volume fraction, volume and mass are represented by SW%, VSW and mSW respectively.
3.3
Correction for SW (CSW)
Correction factor for correcting gross standard volume to net standard volume or gross mass to net mass, for deduction of sediment and water in oil products.
3.4
Volume correction factor (VCF)
Correction factor for correcting the volume of oil products, at observed temperature, to standard volume. It is expressed by the ratio of the volume at standard temperature to that at non-standard temperature, and is equivalent to correction for the temperature of the liquid (CTL).
3.5
Correction for temperature of the shell (CTSh)
Correction factor for correcting the calibrated volume of oil tank at standard temperature (that is, the indicated value in tank capacity table) to the actual volume at service temperature.
3.6
Total observed volume (Vto)
Total measurement volume of all oil products, sediment and water, and free water at observed temperature.
3.7
Gross observed volume (Vgo)
Total measurement volume of all oil products and sediment and water, excluding free water, at observed temperature.
3.8
Gross standard volume (Vgs)
Total volume of all oil products and sediment and water, excluding free water, at standard temperature, which is obtained by correcting the gross observed volume with the appropriate volume correction factor for the observed temperature and standard density.
3.9
Net standard volume (Vns)
Total volume of all oil products, excluding free water and sediment and water, at standard temperature, which is obtained by deducting sediment and water from the gross standard volume.
3.10
Weight, apparent mass in air (m)
Value obtained by weighing the oil products in air, also commonly known as commercial mass or weight, which is different from the mass in vacuum without correction for air buoyancy effect. The apparent mass of oil products in air can also be calculated from the volume of oil products by correcting the air buoyancy effect.
3.11
Weight converting factor (WCF)
Factor that converts the standard volume of oil products to the apparent mass in air, which is equal to the standard density minus the corrected value of air buoyancy. In this standard, the corrected value of air buoyancy is 1.1 kg/m3 or 0.001 1 g/cm3.
3.12
Gross weight (mg)
Weight corresponding to gross standard volume (Vgs).
3.13
Net weight (mn)
Weight corresponding to net standard volume (Vns).
3.14
Total calculated volume (Vtc)
Total volume of all oil products and sediment and water at standard temperature and free water at observed temperature, that is, the sum of gross standard volume and free water volume.
3.15
On-board quantity (OBQ)
All oil products, water, oil sludge and other substances, other than free water, that already exist before loading the oil tanker.
3.16
Remaining on board (ROB)
All oil products, water, oil sludge and other substances, other than free water, that are remained after unloading the oil tanker.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Rounding Off of Numerical Values
5 Preparation of Basic Data
6 Calculation of Gross Observed Volume (Vgo)
7 Calculation of Gross Standard Volume
8 Sediment and Water
9 Calculation of Net Standard Volume
10 Calculation of the Weight, Apparent Mass in Air
11 Calculation of Mass (Mass in Vacuum)
12 Direct Mass Gauging
13 Calculation Sequence
14 Measurement Ticket (or Report)
Appendix A (Informative) Comparison of Clause Numbers between This standard and MPMS Chapter 12.1.1
Appendix B (Informative) Comparison of Symbols of Terms in This Standard at Home and Abroad
Appendix C (Informative) Correction of Oil Gauge Height of Vertical Oil Tanks
Appendix D (Informative) Calculation Method of On-board Quantity (OBQ) or Remaining on Board (ROB)
Appendix E (Informative) Correction of Trim and List of Oil Tankers
Appendix F (Informative) Calculation Process and Examples of Shore Tanks and Oil Tankers
