1、Manual of PetroleumMeasurement StandardsChapter 18Custody TransferSection 1Measurement Procedures for Crude Oil Gathered from Small Tanks by TruckSECOND EDITION, APRIL 1997REAFFIRMED, FEBRUARY 2012Manual of PetroleumMeasurement StandardsChapter 18Custody TransferSection 1Measurement Procedures for C
2、rude Oil Gathered from Small Tanks by TruckMeasurement CoordinationSECOND EDITION, APRIL 1997REAFFIRMED, FEBRUARY 2012SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to partic-ular circumstances, local, state, and federal laws and regulations should be re
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10、erein should also be addressed to the director.API standards are published to facilitate the broad availability of proven, sound engineer-ing and operating practices. These standards are not intended to obviate the need for apply-ing sound engineering judgment regarding when and where these standard
11、s should beutilized. The formulation and publication of API standards is not intended in any way toinhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the markingrequirements of an API standard is solely responsible for complying with all
12、 the applicablerequirements of that standard. API does not represent, warrant, or guarantee that such prod-ucts do in fact conform to the applicable API standard.All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechan
13、ical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 1997 American Petroleum InstituteiiiFOREWORDAPI publications may be used by anyone desiring to do so
14、. Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damag
15、e resultingfrom its use or for the violation of any federal, state, or municipal regulation with which thispublication may conict.Suggested revisions are invited and should be submitted to the Measurement Coordinator,American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005.vCONTENTS
16、Page0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 SCOPE AND FIELD OF APPLICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 REFERENCED PUBLICATIONS. . . . . . . . . . . . . . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . 13 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 THE CUSTODY TRANSFER CONCEPT USED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 GENERAL RESPONSIBILITIES AND CAUTIONS
18、FOR THE COTD . . . . . . . . . . 25.1 Control of Measurement Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.3 Witnessing Sampling,
19、 Gauging, and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 SEQUENCE FOR MEASURING CRUDE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 RUN TICKETS AND TANK TURNDOWNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Tables1Recommended Immersion
20、Times for Woodback Cup-Case Assembly . . . . . . . . . . 32Procedure for Reading a 100-milliliter Cone-Shaped Tube . . . . . . . . . . . . . . . . . . . 73Procedure for Reading a 200-Part Cone-Shaped Tube . . . . . . . . . . . . . . . . . . . . . . . 8Figures1Logic Flow for Custody Transfer of Crude
21、 Oil from Small Tank to Truck . . . . . . . 32Cup-Case Thermometer Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Taking the Outlet and Clearance on Oil Merchantability SamplesSimultaneously. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . 54Reading the Meniscus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65Procedure for Reading Sediment and Water When Using a Tube Reading in100-Milliliters . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、. . . . . . . . . . . . . . . . . . . . . . . . . . 76Procedure for Reading Sediment and Water When Using a Tube Reading in200-Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Spot Sampling Locations. . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91Measurement Procedures for Crude Oil Gathered From Small Tanks by Truck0 IntroductionThese procedures are intended to encourage uniform cus-tody transfer measurement and testing practices for crude oilgathered from small tanks (100
25、0 barrels or less in capacity)by truck; however, they are not intended to interfere withbusiness contracts or local conditions or to comprise the onlyacceptable method of custody transfer by crude oil truck.1 Scope and Field of ApplicationThese procedures are organized into a recommendedsequence of
26、steps for manually determining the quantity andquality of crude oil being transferred under eld conditions.These measurements and tests are performed by crude oiltruck drivers (COTDs) and other parties who are responsiblefor the custody transfer and for recording the results of themeasurements and t
27、ests on run tickets.Since the ownership of the crude oil being gathered maychange and the custody is always passed from the storagetank to the transporting truck as the crude oil passes thetanks last xed outlet ange, accurate custody transfer isextremely important to both the shipper and the carrier
28、.Therefore, all measurements shall be taken carefully andcompleted to the full satisfaction of all parties or theirauthorized representatives.2 Referenced PublicationsThe most recent editions of the following standards, codes,and specications are cited in this standard:ACGIH1Threshold Limit Values f
29、or Chemical Sub-stances and Physical Agents in the WorkEnvironmentAPIPubl 2026 Safe Descent Onto Floating Roofs of Tanksin Petroleum ServicePubl 2217 Guidelines for Work in Conned Spaces inthe Petroleum IndustryRP 2003 Protection Against Ignitions Arising Out ofStatic, Lightning, and Stray CurrentsM
30、anual of Petroleum Measurement StandardsChapter 3 Tank Gauging, Section lA, StandardPractice for the Manual Gauging of Petro-leum and Petroleum ProductsChapter 7 Temperature Determination, Section 1,Static Temperature Determination UsingMercury-in-Glass Tank Thermometersand Section 3, Static Tempera
31、ture Deter-mination Using Portable ElectronicThermometersChapter 8 Sampling, Section 1, Manual Samplingof Petroleum and Petroleum Products(ANSI/ASTM D 4057) and Section 3,Mixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsChapter 9 Density Determination, Section 3,Thermohydromet
32、er Test Method for Den-sity, and API Gravity of Crude Petroleumand Liquid Petroleum Products (ANSI/ASTM D 1298)Chapter 10 Sediment and Water, Section 4, Deter-mination of Sediment and Water in CrudeOil by the Centrifuge Method (Field Pro-cedure) (ANSI/ASTM D 96)OSHA229 Code of Federal RegulationsSec
33、tions1910.1000 and following OccupationalSafety and Health Standards3 Definitions3.1 crude oil truck driver (COTD):assumes that thedriver is also the gauger; however, it should be recognized thatthese duties may be divided between two individuals: a per-son who only drives the tank truck and a gauge
34、r who isresponsible 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 ofcrude oil in the eld from one party to another by performingvarious measurements and quality tests.3.4 meniscus:the concave upper surface o
35、f a liquidcolumn.3.5 merchantable oil:applies to liquid hydrocarbons thatare judged to be acceptable for custody transfer to a carrier.Merchantable oil is settled and contains not more than a spec-ied amount of suspended sediment and water and otherimpurities.3.6 run ticket:the document customarily
36、used to recordlease or facility name, location, test data on crude oil quantityand quality, destination, and gauger and witness signaturesthat are applicable to a particular gathering.1.American Conference of Governmental Industrial Hygienists, 6500 Glen-way Avenue, Building D-5, Cincinnati, Ohio 45
37、211.2.Occupational Safety and Health Administration, U. S. Department ofLabor. The Code of Federal Regulations is available from the U.S. Govern-ment Printing Ofce, Washington, D.C. 20001.2 API CHAPTER18.13.7 sampling:all the steps required to obtain a sample thatis representative of the contents of
38、 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.3.8 sediment and water (S ini-tial merchantability is then assessed. This practice offers thebest known method for manually obtaining the most repre-sentativ
39、e quality samples of the crude oil being gathered.After these quality samples have been obtained for testing,the quantity measurements may be taken without concernfor possible contamination of the quality samples.5 General Responsibilities and Cautions for the COTD5.1 CONTROL OF MEASUREMENT ERRORSLo
40、sses or gains may occur if preventive measures are nottaken against spills, tank overruns, inaccurate measurements,or recording of incorrect measurements on run tickets. Propertruck and tank prepumping checks and alert monitoring dur-ing pumping are two measures that help to prevent losses orgains.
41、Operating the measurement and testing equipmentskillfully and keeping it clean and in top operating conditionare two more preventive measures that help the COTD avoidlosses or gains. A vital link in controlling crude oil losses orgains, the COTD is also responsible for detecting and report-ing defec
42、tive or inadequate control conditions such as internalencrustation of the tank, dents, settling, or leaks.5.2 SAFETYSafety is an essential part of crude oil trucking operationsboth on roadways and during custody transfer, so the COTDmust be thoroughly familiar with all government and com-pany safety
43、 regulations as well as API Recommended Prac-tice 2003, which outlines safety procedures for trucktransports. The following list provides some general safetypractices but serves only as a guideline, and it does not coverall unsafe conditions that might be encountered while per-forming the procedures
44、 contained in this document. Precau-tionary information is also provided in Appendix A.a. Do not smoke around crude oil loading or unloading orduring crude oil testing.b. Connect bonding cables before the hose is connected andleave them in place until the hose is disconnected.c. Minimize the hazards
45、 of static electricity by groundingoneself. This can be accomplished by touching a bare hand orarm to the steel walkway, gauging platform, or tank shellwhen approaching the top of the tank and before opening thetank gauge hatch.d. Attach the gauge tape bonding strap and/or maintain con-tact between
46、the gauge hatch and metal gauge tape at leastuntil the tape bob enters the crude oil layer.e. Stand upwind and to one side with face turned away toavoid fumes while opening and after opening the tank gaugehatch cover.f. Use authorized protective gloves when handling crude oiland solvents during gaug
47、ing and testing.g. Use a hydrogen sulde analyzer and self-contained breath-ing apparatus when gauging crude oil if the lease is postedwith a warning sign for hydrogen sulde.h. Do not use gasoline as a solvent.i. Do not gauge when electrical storms are in the immediatearea.j. Report other unsafe cond
48、itions, such as weak tank ladders,defective valves, and leaks.5.3 WITNESSING SAMPLING, GAUGING, AND TESTINGAll parties directly involved in a custody transfer of crudeoil have the right to witness the quantity measurements andquality tests made during the transfer. These measurementsand tests includ
49、e sampling, gauge reading, temperature tak-ing, S use of a mirror or an approved ashlight may benecessary (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-mometer on a cotton cord through the tanks thief hatch, hold-ing the thermometer at least 12 inches from the side of thetank shell.Note: Do not use a thermometer with a separated mercury column.6.3.2Lower the thermomete
