1、 Standard Test Method Laboratory Screening Test to Determine the Ability of Scale Inhibitors to Prevent the Precipitation of Barium Sulfate or Strontium Sulfate, or Both, from Solution (for Oil and Gas Production Systems) This NACE International standard represents a consensus of those individual me
2、mbers who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. N
3、othing contained in this NACE International standard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infri
4、ngement of Letters Patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usef
5、ulness of this standard in specific instances. NACE International assumes no responsibility for the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its govern
6、ing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users of this NACE International standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this
7、 standard prior to its use. This NACE International standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International
8、 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 regulatory requirements prior to the use of this standard. CAUT
9、IONARY NOTICE: NACE International standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE technical committee procedures. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years fro
10、m 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 International standards may receive current information on all standards and other NACE International publications by contacting
11、the NACE International FirstService Department, 1440 South Creek Dr., Houston, Texas 77084-4906 (telephone +1 281-228-6200). NACE Standard TM0197-2010 Item No. 21228 Revised 2010-10-22 Reaffirmed 2002-04-11 Approved 1997-06-27 NACE International 1440 South Creek Dr. Houston, Texas 77084-4906 +1 281-
12、228-6200 ISBN 1-57590-040-8 2010, NACE International TM0197-2010 NACE International i _ Foreword Mineral scale may be defined as an adherent deposit of predominantly inorganic compounds. A common process leading to scale formation is the precipitation of sparingly soluble salts from oilfield brines.
13、 Some oilfield brines contain sufficient sulfate ion in the presence of barium ions or strontium ions, or both, that the potential for forming barium sulfate (BaSO4) scale or strontium sulfate (SrSO4) scale, or both, exists. Often the formation of scale results in reduced production and increased ma
14、intenance costs. In some locations, naturally occurring radioactive materials have been found to incorporate themselves into the scale. This complication may result in significant health, safety, and liability concerns and increased scale disposal costs. Removal of scale after it has formed is parti
15、cularly difficult when BaSO4and SrSO4are involved. Therefore, oil and gas producers most often use treatment chemicals to inhibit formation of these scales and reduce their tendency to adhere to surfaces. The choice of the best scale inhibitor for a given application often follows a lengthy testing
16、program. The program typically begins with the collection of potentially useful products that are then put through a screening process in the laboratory to determine whether specific products or classes of products perform better than others. NACE Standard TM03741addresses only the screening of CaSO
17、4and CaCO3scale inhibitors. By contrast, this standard test method is intended to provide the user with a relative and quantitative measure of the ability of scale inhibitors to prevent (1) the formation and (2) the precipitation of solid BaSO4or SrSO4, or both, which are necessary and critical stag
18、es in scale deposition. This standard is intended for use by skilled laboratory personnel who have previously performed similar tests. The laboratory screening procedure described in this standard may not allow for the simulation of all oilfield system variables. It must be regarded only as a starti
19、ng point in the evaluation of scale inhibitors. The procedure standardizes the collection of screening test results to facilitate discussion of the results by interested parties. No attempt has been made to define the test brine composition, test temperature, or test duration. Users of this standard
20、 must agree on these and other critical parameters to facilitate comparison of test results. This standard was originally prepared in 1997 by Work Group T-1D-36a, a subgroup of Task Group (TG) T-1D-36, “Scale Inhibitor Evaluation in Oil and Gas Production,” a component of Unit Committee T-1D, “Corro
21、sion Monitoring and Control of Corrosion Environments in Petroleum Operations.” It was reaffirmed in 2002 by Specific Technology Group (STG) 31, “Oil and Gas ProductionCorrosion and Scale Inhibition,” and it was revised in 2010 by TG 383, “Scale Inhibitor Evaluation in Oil and Gas Production.” This
22、standard is issued by NACE International under the auspices 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 conside
23、red mandatory. The term should is used to state something good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. _ TM0197-2010 ii NACE International _ NACE International Standard Test Method Laboratory Screening Test to Determine the Ab
24、ility of Scale Inhibitors to Prevent the Precipitation of Barium Sulfate or Strontium Sulfate, or Both, from Solution (for Oil and Gas Production Systems) Contents 1. General 1 2. Test Equipment . 1 3. Reagents . 2 4. Preparation of Test Solutions 2 5. Test Procedure 3 6. Calculation and Reporting o
25、f Test Results 4 References 4 Appendix A: Sample Stabilization and Analysis (Nonmandatory) 5 _ TM0197-2010 NACE International 1 _ Section 1: General 1.1 This standard describes a test method to screen scale inhibitors for their ability to prevent precipitation of BaSO4or SrSO4, or both, from oilfiel
26、d brines. The test method does not fix such critical variables as test brine composition, test temperature, and test duration. It is the responsibility of the user of this standard to determine the most appropriate choices for these parameters. For example, Pritchard, et al.2address static tests usi
27、ng North Sea brines. 1.2 This standard is intended only for ranking the performance of different scale inhibitors under laboratory conditions. It is not intended to establish field treatment rates. CAUTION: Unique field conditions encountered may alter the performance ranking of the scale inhibitors
28、. 1.3 Factors such as reaction kinetics, fluid velocity, transient composition, temperature and pressure changes, scale adherence, and solids dispersion can significantly affect scale deposition under field conditions. Consideration of these parameters is outside the scope of this standard. However,
29、 field conditions, field brine composition, and other variables noted above should be considered at some point in the scale inhibitor evaluation prior to final selection for field use. _ Section 2: Test Equipment 2.1 Constant-temperature water bath or forced-air oven capable of maintaining the speci
30、fied test temperature. 2.2 Analytical balance capable of weighing mineral salts and other reagents to one-hundredth of the quantity specified. 2.3 Clean, dust-free clear and colorless glass test bottles with a capacity of 100 to 125 mL. Caps must be capable of a positive seal (i.e., they must not de
31、form so as to release pressure generated within the bottle under the test conditions). 2.3.1 The best practice is to use clean, previously unused bottles for each test. 2.3.2 Test bottles may be reused after cleaning if an adequate and consistent procedure is demonstrated to remove sparingly soluble
32、 salts and adsorbed scale inhibitors from the glass surfaces. 2.4 Flasks fitted with dispensers capable of reproducibly delivering 50.0 mL of the test solutions. 2.5 Assorted clear, colorless glass containers for deionized/distilled water, buffer solutions, unfiltered brines, scale inhibitor stock s
33、olutions, post-test analytical samples, etc. 2.6 Filter assembly(ies) capable of filtering brines using 0.45 m cellulose acetate membrane filters. 2.7 A pH meter with an appropriate probe. 2.8 Syringes and 0.2 m cellulose acetate syringe filters for collecting post-test analytical samples. TM0197-20
34、10 2 NACE International _ Section 3: Reagents 3.1 ACS(1)reagent grade3chemicals (mineral salts and organic buffering agents) to prepare test solutions. 3.2 Deionized or distilled water. 3.3 Concentrated solutions of the scale inhibitors to be evaluated. _ Section 4: Preparation of Test Solutions 4.1
35、 Choose an appropriate composite test brine, and specify the concentrations (mg/L) for all species in the composite brine. 4.1.1 If the purpose of performing the screening test relates to a specific field application, the user should choose a composite brine that simulates the scaling brine expected
36、 to occur in the field. 4.1.2 Alternatively, a composite test brine that corresponds to a brine supersaturated in BaSO4or SrSO4, or both, that results from the mixing of a pair of incompatible brines at a chosen mixing ratio and yields the highest supersaturation index or the highest amount of preci
37、pitation may be chosen. Supersaturation indexes and potential precipitation amount may be determined from scaling prediction calculations, such as those used by Patton.44.2 Define two new component brines which, when mixed in equal volumes, result in a composite brine with concentrations equivalent
38、to those specified in Paragraph 4.1. One component brine, Brine A, shall contain all of the polyvalent cations, such as Ba2+and Sr2+, and the other component brine, Brine B, shall contain all of the scaling anions, such as SO42. The remaining ions, such as Na+and Cl, shall be allotted such that the
39、ionic concentrations in the two component brines are comparable if not equal. REMINDER: When equal volumes of the two component brines are mixed to form the composite test brine, the resulting concentration of some ions (including the scaling ions) in the composite brine is one-half of the concentra
40、tion in Brine A or Brine B. 4.3 Define another component brine, Brine C, which differs from Brine B only in that NaCl is used to substitute for the salts containing the scaling anions. The NaCl substitution shall result in a Brine C ionic strength equivalent to that of Brine B.(2) 4.4 CAUTION: Some
41、inhibitors may be incompatible with highly saline brines or with high concentrations of specific cations. A resulting deposit may be mistaken for BaSO4/SrSO4and may remove the inhibitor from the solution. The user of this test method may investigate inhibitor-brine incompatibility by treating the th
42、eoretically nonscaling mixtures of Brine A and Brine C with the highest concentration of the inhibitor(s) being evaluated. 4.5 On the day of the test(3)prepare sufficient quantities of Brine A, Brine B, and Brine C by weighing out the salts and dissolving them in deionized/distilled water to provide
43、 the required ionic concentrations. (1) American Chemical Society (ACS), 1155 Sixteenth St. NW, Washington, DC 20036. (2)Because only salts containing the scaling anions are being replaced, only their contributions to the solutions ionic strength should be calculated. The millequivalents (meq) of di
44、valent anions and cations will be replaced with twice as many meq of chloride and sodium, respectively. For example, 200 meq. of potassium and of sulfate (17.43 g K2SO4) have approximately the same contribution to solution ionic strength as 200 meq. of sodium and 400 meq. of chloride. Therefore, 18.
45、78 g NaCl would be substituted in Brine C for the 17.43 g K2SO4used in the preparation of Brine B. (3)The component brines may be prepared (Paragraphs 4.5 through 4.7) the previous day for convenience. If this approach is used, overnight refrigeration of the brines should be used to retard the loss
46、of dissolved CO2. It is the responsibility of the user of this variation to ensure that satisfactory results are obtained. TM0197-2010 NACE International 3 4.6 Mix sufficient buffer into Brine A so that the composite brine mixtures (A+B, A+C) have the required pH at the test temperatures.(4)The requ
47、ired quantity of buffer should be determined in advance by mixing, at test temperature, appropriate aliquots of Brine A and Brine B and quickly but carefully adding buffer. 4.7 Filter each component brine through a 0.45 m cellulose acetate membrane filter. 4.8 Transfer the component brines to labele
48、d flasks fitted with dispensers capable of reproducibly delivering 50.0 mL to the test bottles. Place the flasks into a constant-temperature bath/oven set at the test temperature. 4.9 Prepare a stock solution of each scale inhibitor to be evaluated. Measure the inhibitor quantity gravimetrically. One-percent solutions
