1、Standard Test Method Field Monitoring of Bacterial Growth in Oil and Gas Systems This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude anyone, whether he or she h
2、as adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE standard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in
3、 connection with any method, apparatus, or product covered by letters patent, or as indemnifying or protecting anyone against liability for infringement of letters patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedur
4、es or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE assumes no responsibility for the interpretation or use of this standard by other parties and accepts r
5、esponsibility for only those official NACE interpretations issued by NACE in accordance with its governing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users of this NACE standard are responsible for reviewing appropriate health, safety, environmen
6、tal, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations det
7、ailed or referred to within this standard. Users of this NACE standard are also responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable re
8、gulatory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE technical committee procedures. NACE requires that action be taken to reaffirm, revise, or withdraw this stan
9、dard no later than five years from the date of initial publication and subsequently from the date of each reaffirmation or revision. The user is cautioned to obtain the latest edition. Purchasers of NACE standards may receive current information on all standards and other NACE publications by contac
10、ting the NACE FirstService Department, 15835 Park Ten Place, Houston, TX 77084-5145 (telephone +1 281-228-6200). Revised 2014-03-08 Revised 2004-11-15 Approved 1994 NACE International 15835 Park Ten Place Houston, Texas 77084-5145 +1 281-228-6200 ISBN 1-57590-192-7 2014 NACE International NACE TM019
11、4-2014 Item No. 21224 TM0194-2014 NACE International i _ Foreword This standard describes field test methods that are useful for estimating bacterial populations, including sessile bacterial populations, commonly found in oilfield systems. The described test methods are those that can be done on sit
12、e and that require a minimum of laboratory equipment or supplies. The described test methods are not the only methods that may be used, but are methods that have been proved to be useful in oilfield situations. This standard is intended to be used by technical field and service personnel, including
13、those who do not necessarily have extensive or specific training in microbiology. However, because microbiology is a specialized field, some pertinent and specific technical information and explanation are provided to the user. Finally, the implications of the results obtained by these test methods
14、are beyond the scope of this standard. The interpretation of the results is site and system specific and may require more expertise than can be provided by this standard. This standard is loosely based on a document produced by the former Corrosion Engineering Association (CEA). CEA operated in the
15、United Kingdom under the auspices of NACE and the Institute of Corrosion (Icorr).(1)This NACE International standard was originally prepared in 1994 by NACE Task Group T-1C-21 under the direction of Unit Committee T-1C, “Corrosion Monitoring in Petroleum Production.” It was revised in 2004 by Task G
16、roup 214, “Bacterial Growth in Oilfield SystemsField Monitoring: Review of NACE Standard TM0194,” which is administered by Specific Technology Group (STG) 31, “Oil and Gas ProductionCorrosion and Scale Inhibition,” and sponsored by STG 60, “Corrosion Mechanisms.” It is issued by NACE under the auspi
17、ces of STG 31. In NACE standards, the terms shall, must, should, and may are used in accordance with the definitions of these terms in the NACE Publications Style Manual. The terms shall and must are used to state a requirement, and are considered mandatory. The term should is used to state somethin
18、g good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. _ (1) Institute of Corrosion (Icorr), P.O. Box 253, Leighton, Buzzard Beds, LU7 7WB, England. TM0194-2014 ii NACE International _ Standard Test Method Field Monitoring of Bacteria
19、l Growth in Oil and Gas Systems Content 1. General 1 2. Sampling Procedures for Planktonic Bacteria . 2 3. Assessment and Sampling of Sessile Bacteria . 4 4. Culture Techniques . 5 5. Evaluation of Chemicals for Control of Bacteria 7 6. Non-Media-Based Field Methods 8 References 9 Bibliography . 11
20、APPENDIXES Appendix A: Glossary (Mandatory) 12 Appendix B: Alternative Methods for Assessing Bacterial Populations (Nonmandatory) . 17 Appendix C: Growth Medium Formulations (Nonmandatory) 19 Appendix D: Membrane Filtration-Aided Bacterial Analyses (Nonmandatory) . 24 Appendix E: Bacterial Culturing
21、 by Serial Dilution (Mandatory) . 25 Appendix F: Example of Use Flow Chart (Nonmandatory) 28 FIGURES Figure E1: Schematic of triplicate serial dilution inoculation (MPN) . 25 Figure F1: Decision Tree for Microbial Testing 28 TABLES Table 1: Results Interpretation Table 6 Table C1: SRB Growth Media 1
22、9 Table C2: Media for Heterotrophic Bacteria . 21 Table C3: Media for Various Types of Phenol Red Broth 21 Table C4: Nitrogen Utilizing Bacteria Media . 22 Table C5: Nitrogen Reducing Bacteria Media 22 Table C6: Methanogenic Media . 22 Table C7: Iron Bacteria Media 23 Table C8: Phosphate-Buffered Sa
23、line (PBS) . 23 Table E1: Single Serial Dilution 27 Table E2: Duplicate Serial Dilution . 27 Table E3: Five Replicate Serial Dilution . 27 _ TM0194-2014 NACE International 1 _ Section 1: General 1.1 Scope 1.1.1 This standard describes field test methods for estimating bacterial populations commonly
24、found in oil and gas systems. Although these techniques have been successful in the oil field, they are not the only methods that are used. Regardless of the method chosen, all techniques should be applied in a consistent manner. It should be recognized that transportation of samples from the field
25、before analysis may significantly change the viability of the bacteria and therefore, whenever practical, analysis should be initiated in the field. It is not the intent of this standard to exclude additional techniques that can be proved useful. However, caution should be exercised with any techniq
26、ue that is at variance from those outlined here. 1.1.2 The presence of bacteria in a system does not necessarily indicate that they are causing a problem. In addition, bacterial populations causing problems in one situation, or system, may be harmless in another. Bacterial population determinations
27、are one more diagnostic tool useful in assessing oilfield problems. 1.1.3 A glossary of terms used in this standard is provided in Appendix A (Mandatory). 1.1.4 This standard deals only with oilfield bacteria generally recognized as harmful in oilfield systems and does not consider other organisms t
28、hat may be found in oilfield fluids, such as phytoplankton (algae), protozoa, or marine organisms such as zooplankton (copepods). 1.1.5 Emphasis is given to sampling methods that are suitable for use in oilfield conditions because effective sampling is essential to any successful analysis. 1.1.6 Not
29、 all bacteria and archaea species can be cultured, and newer molecular microbiology methods are provided in Appendix B (Nonmandatory) to help in identifying microorganisms that cannot be cultured and assessing their roles in the oilfield. Media formulations for enumerating some oilfield bacteria com
30、monly recognized as harmful are given in Appendix C (Nonmandatory). 1.1.7 This standard describes dose-response (constant concentration versus time-kill) testing for evaluating biocides used in oilfield applications. Minimum inhibitory concentration testing versus biostat inhibitor concentration nee
31、ds to be addressed. Minimum inhibitory concentration refers to the amount of inhibitor required to create the desired result. In some cases, the desired result is simply to retard the activity and/or growth of the bacteria in the system. In this case, a biostat may be used with more efficiency than
32、a biocide. In cases in which the desired result is for there to be as few viable bacteria available as possible, a biocide may be necessary. There may be cases in which a biostat and a biocide are the same chemicals applied at different dosages. The minimum inhibitory concentration should be determi
33、ned by testing using the methods outlined in this and other standards. The minimum inhibitory concentration varies with the required result, type of inhibitor, and required dosage to accomplish the objective. 1.1.8 Methods for evaluating surface attached (sessile) bacteria are addressed in Section 3
34、. The importance of these bacteria in oilfield problems is usually not adequately considered. Attached bacterial populations are often the most important component of a systems microbial ecology.1 1.1.9 Methods for the rapid enumeration of bacterial populations activity are addressed in Appendix B.
35、The user must determine the applicability of these methods to the site/system. Similarly, there are a number of commercially available “test kits” for detecting various types of microorganisms that are not discussed in this standard; however, the user could use this standard to evaluate the suitabil
36、ity of these test kits for any particular situation. 1.1.10 Additional information on the corrosion problems associated with bacterial growth in oilfield systems is given in NACE Standard TM0106 and NACE Standard TM0212.2,3TM0194-2014 2 NACE International _ Section 2: Sampling Procedures for Plankto
37、nic Bacteria 2.1 Baseline Sampling 2.1.1 Natural bacterial population fluctuation and uneven bacterial distribution within water systems may hamper accurate assessment of bacteria numbers. If baseline studies described here show a large variation in reported bacterial populations, several samples sh
38、ould be taken on each occasion and combined (bulked). However, this procedure may mask fluctuations in population profiles, if determining such profiles is a goal of the work. 2.1.2 Field operators should be solicited for valuable information. These operators can often provide, or obtain, critical p
39、ast biological monitoring (background) data taken from the system. Communication with operators can also ensure that baseline sampling occurs during normal operations and not during excursions (pigging, shut-ins, biocide treatments, etc.). In addition, selection of proper sample sites can best be ma
40、de in cooperation with operators. 2.1.3 Sampling Frequency 2.1.3.1 Sampling frequency depends on how the field system operates and should encompass the various stages of its operation. 2.1.3.2 Some systems may exhibit large population variations over a short time. To establish the natural variation
41、in bacteria numbers, samples (bulked or otherwise) should normally be taken randomly over several days to establish a baseline. This work should also establish the sample points that are representative of the system. As an example of what sample frequency might be required, twice-daily sampling over
42、 three to five days is often used. In other cases, greater sample frequencies over longer time periods may be required. 2.1.3.3 If the evaluation spans several months, it is important to account for any system variables that are related to seasonal changes. Usually, these variables can only be estab
43、lished with extensive background monitoring. 2.1.3.4 During biocide treatments, additional samples should normally be taken immediately before treatment and at random intervals over several days after each treatment. A good procedure would be to match the sampling schedule used with the baseline sam
44、pling for the system. 2.1.3.5 To fully understand the ecology of a system, suitable representation of the entire system should be surveyed rather than only areas where elevated bacterial populations are expected or where obvious bacterial problems are occurring. Data points should be generated over
45、time to identify possible trends. 2.2 Sampling Bottles 2.2.1 It should be assumed that bacterial populations undergo both qualitative and quantitative changes with time while being held in any sample container. Sterile sample containers should be used. Samples that were collected in non-sterile cont
46、ainers should be so noted. 2.2.2 To minimize changes, the sample should be analyzed without delay, preferably on site. If a delay of more than one hour is unavoidable, it should be noted that errors in bacterial population estimates still could result. If the delay is greater than 48 h, the sample s
47、hould be refrigerated. If samples are not immediately analyzed on site, the containers must be sealed and placed in a cooler or refrigerator to reduce the bacterial metabolism until testing is performed. Testing should be performed only after the refrigerated samples have been allowed to warm up to
48、ambient temperature. The time delay occurring between sampling and analysis should be held constant for all testing. For example, if some samples are normally analyzed 4 h after collection, all samples should be held for 4 h before testing. This practice helps minimize population variability caused by the sample handling procedure. For handling thermophilic bacteria, special precautions may need to be observed. Samples should also be protected from sunli
