1、Recommended Practice for Oil and Gas Well Servicing and Workover Operations Involving Hydrogen SulfideAPI RECOMMENDED PRACTICE 68FIRST EDITION, JANUARY 1998REAFFIRMED, SEPTEMBER 2010Recommended Practice for Oil and Gas Well Servicing and Workover Operations Involving Hydrogen SulfideUpstream Segment
2、API RECOMMENDED PRACTICE 68FIRST EDITION, JANUARY 1998REAFFIRMED, SEPTEMBER 2010SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to partic-ular circumstances, local, state, and federal laws and regulations should be reviewed.API is not undertaking to meet
3、the duties of employers, manufacturers, or suppliers towarn and properly train and equip their employees, and others exposed, concerning healthand safety risks and precautions, nor undertaking their obligations under local, state, or fed-eral laws.Information concerning safety and health risks and p
4、roper precautions with respect to par-ticular materials and conditions should be obtained from the employer, the manufacturer orsupplier of that material, or the material safety data sheet.Nothing contained in any API publication is to be construed as granting any right, byimplication or otherwise,
5、for the manufacture, sale, or use of any method, apparatus, or prod-uct covered by letters patent. Neither should anything contained in the publication be con-strued as insuring anyone against liability for infringement of letters patent.Generally, API standards are reviewed and revised, reaffirmed,
6、 or withdrawn at least everyfive years. Sometimes a one-time extension of up to two years will be added to this reviewcycle. This publication will no longer be in effect five years after its publication date as anoperative API standard or, where an extension has been granted, upon republication. Sta
7、tusof the publication can be ascertained from the API Authoring Department telephone (202)682-8000. A catalog of API publications and materials is published annually and updatedquarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.This document was produced under API standardization procedur
8、es that ensure appropri-ate notification and participation in the developmental process and is designated as an APIstandard. Questions concerning the interpretation of the content of this standard or com-ments and questions concerning the procedures under which this standard was developedshould be d
9、irected in writing to the director of the Authoring Department (shown on the titlepage of this document), American Petroleum Institute, 1220 L Street, N.W., Washington,D.C. 20005. Requests for permission to reproduce or translate all or any part of the materialpublished herein should also be address
10、ed 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 standards should beutilized. The for
11、mulation 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 the applicablerequirements
12、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, mechanical, photocopying, recordin
13、g, 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 1998 American Petroleum InstituteFOREWORDThese recommended practices were prepared by the API Subcommittee on Oil and GasWell Se
14、rvicing and Workover Operations Involving Hydrogen Sulfide. This standard isunder the administration of the American Petroleum Institute Exploration 2) that may be impractical under certain circumstances; or 3) thatmay be unnecessary under certain circumstances.Suggested revisions to these recommend
15、ed practices are invited and should be submittedto: Director, Exploration amended by CPL2-20A CH-1, October 29, 1984.3.2.3 continuous hydrogen sulfide monitoringequipment: Equipment capable of continuously measuringand displaying the concentration of hydrogen sulfide in ambi-ent air.3.2.4 emergency
16、response planning guidelevel2 (ERPG-2): The maximum airborne concentration belowwhich it is believed that nearly all individuals could beexposed for up to one hour without experiencing or develop-ing irreversible or other serious health effects or symptomsthat could impair their abilities to take pr
17、otective actions.Refer to Technical Guidance for Hazards Analysis; Emer-gency Planning for Extremely Hazardous Substances. 3.2.5 enclosed facility: A 3-dimensional space enclosedby more than 2/3of the possible projected plane surface andof sufficient size to allow the entry of personnel. For a typic
18、albuilding, this would require that more than 2/3of the walls,ceiling, and floor be present. Refer to API RP 500.3.2.6 essential personnel: Those individuals requiredto provide proper and prudent safe operations activities andthose required to effect control of the hazardous hydrogensulfide or sulfu
19、r dioxide conditions.3.2.7 gas detection instrument: An assembly of elec-trical, mechanical, and chemical components designed tosense and respond continuously to the presence of chemicalgases in atmospheric mixtures.3.2.8 hydrogen sulfide: Chemical formula is H2S. Aflammable, toxic gas that is norma
20、lly heavier than air andsometimes found in fluids encountered in oil and gas produc-ing and gas processing operations. CAUTION: Inhalation atcertain concentrations can lead to injury or death. Refer toAppendix A.3.2.9 immediately dangerous to life and health(IDLH): An atmospheric concentration of an
21、y toxic, corro-sive, or asphyxiant substance that poses an immediate threatto life or would cause irreversible or delayed adverse healtheffects or would interfere with an individuals ability toescape from a dangerous atmosphere. API Publication 2217Aspecifies an oxygen content of less than 19.5% as
22、oxygendeficient and an oxygen content of less than 16% is consid-ered IDLH.3.2.10 inadequately ventilated: Ventilation (natural orartificial) that is not sufficient to prevent the accumulation ofRECOMMENDED PRACTICES FOR OIL AND GAS WELL SERVICING AND WORKOVER OPERATIONS INVOLVING HYDROGEN SULFIDE 5
23、significant quantities of toxic or inert gases such that a hazardis created.3.2.11 length-of-stain detector: A specially designedpump and colorimetric indicator tube detector (length-of-stain), with a supply of detector tubes, that operates by usingthe pump to pull a known volume of air or gas throu
24、gh adetector tube. The tubes contain chemical reagents that aredesigned to detect the presence and display the concentrationof specific gases or vapors in the sample. The length of theresultant color band in the tube indicates an instantaneousquantitative concentration of the specific chemical in th
25、e sam-ple.3.2.12 permissible exposure limit (PEL): The inhala-tion exposure limit specified in 29 CFR 1910.1000 or applica-ble state standards. These limits may be expressed as an 8-hour time weighted average (TWA), a Ceiling Limit, or 15-minute Short Term Exposure Limit (STEL). PELs are subjectto c
26、hange and users should check the latest version of 29 CFRPart 1910.1000, “Toxic and Hazardous Substances,” for com-pliance.3.2.13 shall: Indicates the “recommended practice(s)” hasuniversal applicability to that specific activity.3.2.14 shelter-in-place: The concept of providing thepublic protection
27、 from exposure to toxic gas or vapor releasesto the environment by having residents stay indoors untilemergency evacuators arrive or the emergency is over. Referto Section 2.3, 7.11.3.2.15 should: Denotes a “recommended practice(s)” 1) where a safe comparable alternative practice(s) is avail-able; 2
28、) that may be impractical under certain circum- tances; or 3) that may be unnecessary under certain cir-cumstances.3.2.16 sulfur dioxide: Chemical formula is SO2. A toxicproduct of combustion of hydrogen sulfide, normally heavierthan air. CAUTION: Inhalation at certain concentrations canlead to inju
29、ry or death. Refer to Appendix B.3.2.17 temporary safe haven: Refer to “shelter-in-place” (3.2.14).3.2.18 threshold limit value (TLV): Airborne concen-trations of substances representing conditions under which itis believed that nearly all workers may be repeatedly exposedday after day without adver
30、se effects. These value may beexpressed as 8-hour time weighted average (TWA), CeilingLimits, or 15-minute Short Term Exposure Limits (STEL).Refer to American Conference of Governmental IndustrialHygienists (ACGIH), Threshold Limit Values for ChemicalSubstances and Physical Agents and Biological Exp
31、osureIndices. “TLV” is a trademarked term of ACGIH. TLVs aresubject to change and users should check the latest edition ofthe forestated reference.4 Applicability4.1 PERSONNEL AND EQUIPMENT PROTECTIONIn oil and gas well servicing/workover operations, severityof the environment shall be assessed. As
32、a minimum, the fol-lowing measures shall be implemented: a. Personnel protection should be provided if the work areaconcentration of hydrogen sulfide (refer to 3.2.8) exceeds 10ppm 8-hour time weighted average (TWA) or 15 ppm as ashort term exposure level (STEL) averaged over 15 minutes(refer to App
33、endix A); or the work area concentration of sul-fur dioxide (refer to 4.16) exceeds 2 ppm as an 8-hour TWAor 5 ppm as a STEL averaged over 15 minutes (refer toAppendix B). Personnel safety provisions of this publicationdo not apply when: 1. the atmospheric concentration of hydrogen sulfidecould not
34、exceed 10 ppm (by volume) in the breathingzone; or 2. the atmospheric concentration of sulfur dioxide couldnot exceed 2 ppm (by volume) in the breathing zone. b. Equipment and materials shall be selected on the basis ofresistance to sulfide stress cracking and corrosion. Refer toNACE Standard MR0175
35、 for recommendations for selectionof equipment and materials.The equipment and materials provisions of this publicationdo not apply when the partial pressure of hydrogen sulfide inthe gas could not exceed 0.05 psia or 10 psia in the gas phaseof sour crude systems.Some conditions may require extensiv
36、e personnel safetymeasures but only the use of conventional equipment andmaterials; other conditions may require the use of specialequipment and materials but only minimal personnel safetymeasures; still other conditions may require both.Throughout this publication, “trigger levels” for variousactio
37、ns are used to ensure safety of employees and the public.These trigger levels have been established considering thresh-old limit values (TLVsrefer to 3.2.18). These TLVs are sub-ject to change and users should check the latest edition ofThreshold Limit Values and Biological Exposure Indices andthe l
38、atest revision of 29 CFR Part 1910.1000 for compliance.In 1989, the U. S. Department of Labor, OccupationalSafety and Health Administration (OSHA) issued updatedpermissible exposure limits (PELs) for several hundredchemicals, including revised PELs for hydrogen sulfide (10ppm as an 8-hour TWA or 15
39、ppm STEL averaged over 15minutes) and sulfur dioxide 2 ppm as an 8-hour TWA or 5ppm STEL averaged over 15 minutes (refer to 54 FR 2333,January 19, 1989). A federal court set aside the OSHA 1989rule (refer to 58 FR 35338, June 30, 1993).6 API RECOMMENDED PRACTICE 68The American Conference of Governme
40、ntal IndustrialHygienists (ACGIH) recommends a hydrogen sulfide TLV of10 ppm (8-hour TWA) and a STEL of 15 ppm averaged over15 minutes and recommends 2 ppm as an 8-hour TWA TLVand 5 ppm as a STEL averaged over 15 minutes for sulfurdioxide (refer to Threshold Limit Values for Chemical Sub-stances and
41、 Biological Exposure Indices).In the interest of safety and health, this standard recom-mends use of the ACGIH TLVs (refer to Threshold Limit Val-ues for Chemical Substances and Physical Agents andBiological Exposure Indices) as trigger levels for employeesafety (refer to Appendices A and B). Some s
42、tates haveadopted these levels as requirements for employee safety.Individual employers may set their own trigger levels afterreview and due consideration of site specific conditions, vari-ous regulatory requirements, and material safety data sheet(MSDS) information. Users should check the current s
43、tatus ofOSHA PELs, OSHA acceptable ceiling concentrations(ACCs), ACGIH TLVs, and applicable regulatory require-ments concerning substances of interest.4.2 LEGAL REQUIREMENTSThis publication presents recommended practices and pre-cautions deemed pertinent to protect personnel and the publicfrom expos
44、ure to potentially hazardous concentrations ofhydrogen sulfide and sulfur dioxide. These recommendedpractices recognize that owners, operators, contractors, andtheir employees have separate responsibilities that may becontractual in nature. It is not the intent of these recom-mended practices to alt
45、er the contractual relationship(s)between the parties. Some of the practices recommendedherein are mandatory by local, state, or federal laws, rules,and regulations. Because of the functional and geographicaldiversity of these requirements, no attempt has been made inthese recommended practices to d
46、esignate which are optionaland which are required. Furthermore, even if all the practicesrecommended herein are followed, there still may be existingor future legally imposed laws or regulations which wouldnot be met. In the event of any omission or conflict betweenthese recommended practices and le
47、gally required action(s),the requirements of laws and regulations must control. Someof the federal regulations (standards) pertinent to safe wellservicing/workover operations involving hydrogen sulfide arelisted in Section 2, “References.” Users of this publicationshould review these regulations and
48、 other federal, state, andlocal laws to assure appropriate compliance in their specificoperations.4.3 HAZARD COMMUNICATION (WORKER RIGHT-TO-KNOW)This publication contains important information that isintended as a guide but may not comply in all respects withOSHAs Hazard Communication Standard. Appr
49、opriatecounsel should be sought to assure compliance with hazardcommunication requirements for the specific operations.Refer to OSHA rules on hazard communication in 29 CFRPart 1910.1200, “Hazard Communication Standard” (52 FR31877-31886, August 24, 1987). 4.4 EMERGENCY PLANNING AND COMMUNITY RIGHT-TO-KNOW ACT (EPCRA) AND COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT (CERCLA)The Emergency Planning and Community Right-to-KnowAct (EPCRA), also known as Title III of the SuperfundAmendments and Reauthorization Act of 1986 (SARA III),requires facilities with a thre
