1、Manual of Petroleum Measurement Standards Chapter 18Custody Transfer Section 1Measurement Procedures for Crude Oil Gathered from Small Tanks by Truck SECOND EDITION, APRIL 1997 REAFFIRMED, FEBRUARY 2012Manual of Petroleum Measurement Standards Chapter 18Custody Transfer Section 1Measurement Procedur
2、es for Crude Oil Gathered from Small Tanks by Truck Measurement Coordination SECOND EDITION, APRIL 1997 REAFFIRMED, FEBRUARY 2012 SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to partic- ular circumstances, local, state, and federal laws and regulations
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16、e, 1220 L Street, N.W., Washington, D.C. 20005. vCONTENTSPage 0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 SCOPE AND FIELD OF APPLICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 REFEREN
17、CED PUBLICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 THE CUSTODY TRANSFER CONCEPT USED . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . 2 5 GENERAL RESPONSIBILITIES AND CAUTIONS FOR THE COTD . . . . . . . . . . 2 5.1 Control of Measurement Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5.2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . 2 5.3 Witnessing Sampling, Gauging, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6 SEQUENCE FOR MEASURING CRUDE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 7 RUN TICKETS AND TANK TURNDOWNS . . . . . . . . . . . .
20、. . . . . . . . . . . . . . . . . . . 9 Tables 1Recommended Immersion Times for Woodback Cup-Case Assembly . . . . . . . . . . 3 2Procedure for Reading a 100-milliliter Cone-Shaped Tube . . . . . . . . . . . . . . . . . . . 7 3Procedure for Reading a 200-Part Cone-Shaped Tube . . . . . . . . . . . .
21、 . . . . . . . . . . . 8 Figures 1Logic Flow for Custody Transfer of Crude Oil from Small Tank to Truck . . . . . . . 3 2Cup-Case Thermometer Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3Taking the Outlet and Clearance on Oil Merchantability Samples Simulta
22、neously. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4Reading the Meniscus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5Procedure for Reading Sediment and Water When Using a Tube Rea
23、ding in 100-Milliliters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6Procedure for Reading Sediment and Water When Using a Tube Reading in 200-Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、. . . . . . . . . . . . . . . . 8 7Spot Sampling Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1Measurement Procedures for Crude Oil Gathered From Small Tanks by Truck0 IntroductionThese procedures are intended to encourage uniform cus- tody t
25、ransfer measurement and testing practices for crude oil gathered from small tanks (1000 barrels or less in capacity) by truck; however, they are not intended to interfere with business contracts or local conditions or to comprise the only acceptable method of custody transfer by crude oil truck.1 Sc
26、ope and Field of ApplicationThese procedures are organized into a recommended sequence of steps for manually determining the quantity and quality of crude oil being transferred under eld conditions. These measurements and tests are performed by crude oil truck drivers (COTDs) and other parties who a
27、re responsible for the custody transfer and for recording the results of the measurements and tests on run tickets. Since the ownership of the crude oil being gathered may change and the custody is always passed from the storage tank to the transporting truck as the crude oil passes the tanks last x
28、ed outlet ange, accurate custody transfer is extremely important to both the shipper and the carrier. Therefore, all measurements shall be taken carefully and completed to the full satisfaction of all parties or their authorized representatives.2 Referenced PublicationsThe most recent editions of th
29、e following standards, codes, and specications are cited in this standard: ACGIH1Threshold Limit Values for Chemical Sub- stances and Physical Agents in the Work EnvironmentAPI Publ 2026 Safe Descent Onto Floating Roofs of Tanks in Petroleum ServicePubl 2217 Guidelines for Work in Conned Spaces in t
30、he Petroleum IndustryRP 2003 Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents Manual of Petroleum Measurement StandardsChapter 3 Tank Gauging, Section lA, Standard Practice for the Manual Gauging of Petro- leum and Petroleum Products Chapter 7 Temperature Determinati
31、on, Section 1, Static Temperature Determination Using Mercury-in-Glass Tank Thermometers and Section 3, Static Temperature Deter- mination Using Portable Electronic Thermometers Chapter 8 Sampling, Section 1, Manual Sampling of Petroleum and Petroleum Products (ANSI/ASTM D 4057) and Section 3, Mixin
32、g and Handling of Liquid Samples of Petroleum and Petroleum Products Chapter 9 Density Determination, Section 3, Thermohydrometer Test Method for Den- sity, and API Gravity of Crude Petroleum and Liquid Petroleum Products (ANSI/ ASTM D 1298) Chapter 10 Sediment and Water, Section 4, Deter- mination
33、of Sediment and Water in Crude Oil by the Centrifuge Method (Field Pro- cedure) (ANSI/ASTM D 96) OSHA229 Code of Federal RegulationsSections 1910.1000 and following Occupational Safety and Health Standards3 Denitions3.1 crude oil truck driver (COTD):assumes that the driver is also the gauger; howeve
34、r, it should be recognized that these duties may be divided between two individuals: a per- son who only drives the tank truck and a gauger who is responsible for measurement and testing.3.2 free water:the water that exists as a separate phase.3.3 gathering:the process of transferring the custody of
35、 crude oil in the eld from one party to another by performing various measurements and quality tests.3.4 meniscus:the concave upper surface of a liquid column.3.5 merchantable oil:applies to liquid hydrocarbons that are judged to be acceptable for custody transfer to a carrier. Merchantable oil is s
36、ettled and contains not more than a spec- ied amount of suspended sediment and water and other impurities.3.6 run ticket:the document customarily used to record lease or facility name, location, test data on crude oil quantity and quality, destination, and gauger and witness signatures that are appl
37、icable to a particular gathering.1.American Conference of Governmental Industrial Hygienists, 6500 Glen- way Avenue, Building D-5, Cincinnati, Ohio 45211.2.Occupational Safety and Health Administration, U. S. Department of Labor. The Code of Federal Regulations is available from the U.S. Govern- men
38、t Printing Ofce, Washington, D.C. 20001. 2 API CHAPTER18.13.7 sampling:all the steps required to obtain a sample that is representative of the contents of any pipe, tank, or other ves- sel and to place that sample in a container from which a repre- sentative test specimen can be taken for analysis.3
39、.8 sediment and water (S ini- tial merchantability is then assessed. This practice offers the best known method for manually obtaining the most repre- sentative quality samples of the crude oil being gathered. After these quality samples have been obtained for testing, the quantity measurements may
40、be taken without concern for possible contamination of the quality samples.5 General Responsibilities and Cautions for the COTD5.1 CONTROL OF MEASUREMENT ERRORSLosses or gains may occur if preventive measures are not taken against spills, tank overruns, inaccurate measurements, or recording of incor
41、rect measurements on run tickets. Proper truck and tank prepumping checks and alert monitoring dur- ing pumping are two measures that help to prevent losses or gains. Operating the measurement and testing equipment skillfully and keeping it clean and in top operating condition are two more preventiv
42、e measures that help the COTD avoid losses or gains. A vital link in controlling crude oil losses or gains, the COTD is also responsible for detecting and report- ing defective or inadequate control conditions such as internal encrustation of the tank, dents, settling, or leaks.5.2 SAFETYSafety is a
43、n essential part of crude oil trucking operations both on roadways and during custody transfer, so the COTD must be thoroughly familiar with all government and com- pany safety regulations as well as API Recommended Prac- tice 2003, which outlines safety procedures for truck transports. The followin
44、g list provides some general safety practices but serves only as a guideline, and it does not cover all unsafe conditions that might be encountered while per- forming the procedures contained in this document. Precau- tionary information is also provided in Appendix A. a. Do not smoke around crude o
45、il loading or unloading or during crude oil testing. b. Connect bonding cables before the hose is connected and leave them in place until the hose is disconnected. c. Minimize the hazards of static electricity by grounding oneself. This can be accomplished by touching a bare hand or arm to the steel
46、 walkway, gauging platform, or tank shell when approaching the top of the tank and before opening the tank gauge hatch. d. Attach the gauge tape bonding strap and/or maintain con- tact between the gauge hatch and metal gauge tape at least until the tape bob enters the crude oil layer. e. Stand upwin
47、d and to one side with face turned away to avoid fumes while opening and after opening the tank gauge hatch cover. f. Use authorized protective gloves when handling crude oil and solvents during gauging and testing. g. Use a hydrogen sulde analyzer and self-contained breath- ing apparatus when gaugi
48、ng crude oil if the lease is posted with a warning sign for hydrogen sulde. h. Do not use gasoline as a solvent. i. Do not gauge when electrical storms are in the immediate area. j. Report other unsafe conditions, such as weak tank ladders, defective valves, and leaks.5.3 WITNESSING SAMPLING, GAUGIN
49、G, AND TESTINGAll parties directly involved in a custody transfer of crude oil have the right to witness the quantity measurements and quality tests made during the transfer. These measurements and tests include sampling, gauge reading, temperature tak- ing, S use of a mirror or an approved ashlight may be necessary (see API Recommended Practice 2003).6.3Suspend the cup-case thermometer in the tank (see Fig- ure 2).6.3.1After making sure that the thermometer (see note) has no breaks in its mercury column, lower the cup-case ther- mome
