1、NACE Standard SPO181-2006 (formerly RP0181-94) Item No. 21025 Standard Practice Liquid-Applied Internal Protective Coatings for Oilfield Production Equipment This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions
2、. 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. Nothing contained in this NACE International standard is to be co
3、nstrued 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 infringement of Letters Patent. This standard represents minimum requ
4、irements 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 usefulness of this standard in specific instances. NACE Internationa
5、l 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 governing procedures and policies which preclude the issuance of inter
6、pretations 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 standard prior to its use. This NACE International standard may
7、 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 standard are also responsible for establishing appropriate heal
8、th, 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. CAUTIONARY NOTICE: NACE International standards are subject to perio
9、dic review, and may be revised or withdrawn at any time without prior notice. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. Purchasers
10、of NACE International standards may receive current information on all standards and other NACE International publications by contacting the NACE Firstservice Department, 1440 South Creek Dr., Houston, Texas 77084-4906 (telephone +I 281/228-6200). Revised 2006-06-23 Revised 1994 Approved 1981 NACE I
11、nternational 1440 South Creek Dr. Houston, TX 77084-4906 +I 281/228-6200 ISBN 1-5790-205-2 O 2006, NACE International SPO181-2006 Foreword This standard practice provides guidelines for obtaining an effective internal coating or corrosion barrier to protect against general or pitting corrosion of pr
12、oduction equipment commonly used in oilfield operations at atmospheric and elevated pressures. This standard is not applicable to the internal or external coating of tubing, casing, line pipe, or other tubular goods. This standard is intended for end users, applicators, and manufacturers. This stand
13、ard details various factors required to obtain a satisfactory coating, including production equipment design and fabrication considerations, surface preparation, coating application, and inspection. Determination of the need for coating, selection of portions of the production equipment to be coated
14、, and selection of a coating are outside the scope of this standard. These decisions must be based on the users experience, knowledge of the system conditions, project economics, and environmental and safety considerations. Because numerous excellent coatings are available, no attempt was made to li
15、st all of the coatings suitable for this service. This standard was originally prepared in 1981 by Task Group T-IG-20, a component of former Unit Committee T-1G on Protective Coatings and Nonmetallic Materials for Oilfield Use, to replace former NACE Standard RP0372. It was revised in 1994 by T-IG-2
16、0, and in 2006 by Task Group (TG) 087 on STG 33 Standards and Technical Committee Reports: Revision, Reaffirmation, or Withdrawal. TG 087 is administered by Specific Technology Group (STG) 33 on Oil and Gas Production-Nonmetallics and Wear Coatings (Metallic), and sponsored by STG 03 on Coatings and
17、 Linings, Protective: Immersion and Buried Service. It is issued by NACE under the auspices of STG 33. 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, 4th ed., Paragraph 7.4.1.9. Shall and mus
18、t are used to state mandatory requirements. The term should is used to state something considered good and is recommended but is not mandatory. The term may is used to state something considered optional. NACE International I SPO181-2006 NACE International Stand a rd Practice Liquid-Applied Internal
19、 Protective Coatings For Oilfield Production Equipment Contents 1. General 1 2. Definitions . . 6 7 7 9. Laboratory and Field Testing . 6 IO. Monitoring, Records, and Maintenance References Appendix A-Placing tion for Bolted Tanks Appendix D-Reinspection Report: Internal Coating on Production Equipm
20、ent (After Period of Service) . . 12 9 10 Figure AI : Placing Caulk, Putty, or Filler Figure BI: Undercutting Gaskets . Figure B2: Caulking Seams and Chi Table l-Partial Listing of Coatings Table 2-Relationship Between Coating Thickness and Anchor Pattern Table 3-Recommended Voltages for High-Voltag
21、e Spark Testing II NACE International SPO181-2006 Section 1: General 1 .I Introduction production equipment used primarily for the processing and storage of corrosive fluids in oilfield operations. 1.1.1 This standard presents procedures for applying liquid coatings to the interior of various types
22、of oilfield 1 .I .2 The area of production equipment to be coated may either be the entire interior sutface area or only those areas where corrosion is a concern. Section 2: Definitions Production Equipment: All atmospheric and pressurized Coating: A liquid, liquefiable, or mastic composition that,
23、metal tanks and vessels used in oilfield operations, after application to a sutface, is converted into a solid including, but not limited to, oil and water storage tanks, separators/treaters, and deaeration towers. This does not include tubing, casing, pipelines, or other tubular goods. protective,
24、decorative, or functional adherent film. Section 3: Production Equipment Design and Fabrication 3.1 Welded tanks are preferred over bolted tanks because complete coating coverage is easier to obtain on welded joints than on bolted channels and gasketed joints. 3.2 Production equipment should be desi
25、gned and fabricated to allow easy access for sutface preparation and coating of internal surfaces that require a coating for corrosion protection.-5 It is essential that these sutfaces receive the required sutface preparation and uniform coating. 3.2.1 The shell of production equipment shall be desi
26、gned to facilitate grinding, blasting, and coating. All inlet deflector plates, agitators, anti-swirl baffles, gauging devices, internal piping, and other internal sutfaces as specified by the purchaser shall be removable and/or designed to facilitate grinding, blasting, and coating. All internal ca
27、rbon steel pipe should be removable and designed for ease of cleaning and coating. 3.2.2 Manways shall be installed to provide adequate ventilation and access to all interior areas for grinding, blasting, and coating. For easy access, manways should be 500 mm (20 in.) in diameter or larger. 3.2.3 To
28、 prevent galvanic corrosion of carbon steel equipment, any corrosion-resistant alloy internals should as a preference be electrically isolated from the carbon steel. When this is impractical, coating of the carbon steel should be extended onto the corrosion- resistant alloy to isolate the intetface
29、from the corrosive medium. When practical, this should be for a minimum distance of 50 mm (2 in.) 3.2.4 All attachments to the internal sutface of the production equipment shall be continuously welded to prevent any voids or appendages that cannot be properly cleaned and coated. All sutfaces to be c
30、oated must be accessible to applicator and equipment. 3.2.5 For coatings with a thickness of 250 pm (1 O mil) or less, welds shall be ground to a smooth contour, with all defects repaired or removed in accordance with NACE Standard RP0178 Weld Preparation Designation C or better. Sharp wave crests,
31、slag pits, and slag shall be ground away, leaving a smooth, rounded base for the coating; this does not require grinding flush to the plate. 3.2.6 For coatings with a thickness greater than 250 pm (1 O mil) but not exceeding 1,000 pm (40 mil), welds shall be ground smooth and blended in accordance w
32、ith NACE Standard RPOI 78 Weld Preparation Designation D or better. Weld splatter shall be removed and welds shall be ground smooth and blended into the plate sutfaces. 3.2.7 For coatings with a thickness greater than 1,000 pm (40 mil), welds shall be minimally ground in accordance with NACE Standar
33、d RP0178 Weld Preparation Designation E or better. Sharp projections on the weld bead, slag, and weld splatter shall be removed. 3.2.8 All sharp edges that are to be coated, including those on bolt holes, shall be rounded by grinding to a smooth contour radius. Edges or projections shall not be hamm
34、ered. NACE International 1 SPO181-2006 3.3 Welded tanks should be inspected to ensure they meet the design criteria of Paragraph 3.2. 3.4 Hydrotesting and stress relieving, if required, should be done prior to the application of any coating. Section 4: Coating Types 4.1 Many coatings are currently a
35、vailable in the industry (e) Ambient temperature and humidity at the time the and new coatings are continually being introduced.6 coating will be applied should be considered; Selection of a coating system for a specific application is beyond the scope of this standard. However, for proper (f) Envir
36、onment and handling of the equipment during coating selection the following parameters should be shipping and/or storage to prevent coating damage should considered by the user. be considered; (a) Fluid composition and concentration of gas, oil, water, and additives such as biocides should be consid
37、ered; (b) Intended service life and service operating conditions, temperature, pressure, and velocity should be considered. Maximum, minimum, and cycling temperatures and pressures the production equipment will be subjected to during service life should be considered; (c) Cathodic protection (CP) sh
38、ould be considered in conjunction with coatings. However, applying excessive voltage can cause loss of coating adhesion to steel; (d) Metallurgy of the production equipment or internal components such as galvanizing, zinc, or stainless steel should be considered; (9) The selected primer should be co
39、mpatible with subsequent coats. Each coat of the coating system should be compatible with the previous coat; and (h) Physical abuse, e.g., manual cleaning or inspection of the production equipment during service life, etc., should be considered. 4.2 A partial listing of coatings in use for corrosion
40、 control in oil and gas production equipment is presented in Table 1. Because no one coating is suitable for all environments, coating selection should be based on laboratory data and past field petformance. 4.3 There are several shop-applied powder coatings that can also be used in production equip
41、ment. TABLE 1 PARTIAL LISTING OF COATINGS USED IN OIL AND GAS PRODUCTION EQUIPMENT Coating Material Generic Type Total Dry Film Thickness Range Fluoropolymers Ba ked E poxy-Mod ified Phenolics Baked Thin-Film Phenolics Cata1 yzed/Ba ked U ret hanes Epoxy Amines Catalyzed E poxy-Mod ified Phenolics E
42、poxy Polyamides Coal Tar Epoxies Flake-Filled Epoxies Flake-Filled Polyesters Flake-Filled Vinyl Esters Fiberglass-Reinforced Epoxies Fiberglass-Reinforced Polyesters Fiberglass-Reinforced Vinyl Esters Polyvinylidene Fluorides 50 to 125 pm (2 to 5 mil) 125 to 200 pm (5 to 8 mil) 125 to 200 pm (5 to
43、8 mil) 125 to 225 pm (5 to 9 mil) 250 to 375 pm (1 O to 15 mil) 250 to 375 pm (1 O to 15 mil) 250 to 375 pm (IO to 15 mil ) 250 to 500 pm (IO to 20 mil) 750 to 1,000 pm (30 to 40 mil) 750 to 1,000 pm (30 to 40 mil) 750 to 1,000 pm (30 to 40 mil) 1,000 to 3,000 pm (40 to 120 mil) 1,000 to 3,000 pm (4
44、0 to 120 mil) 1,000 to 3,000 pm (40 to 120 mil) 500 to 1,500 pm (20 to 60 mil) 2 NACE International SPO181-2006 5.1 Prior to sutface preparation and if design allows, newly bolted storage tanks that will be coated before being placed in service should be filled with fresh water to check for leaks an
45、d expand all chimes (bottom-to-shell corner) to final position. Necessary repairs shall be completed and the tank dried before su tface preparation beg ins. 5.2 Production equipment previously used in hydrogen sulfide (H2S) service can be difficult to coat because of sulfide contamination. Wet or dr
46、y abrasive blasting removes most corrosion products, including sulfides; however, sulfide corrosion of carbon steel often occurs as pitting. Dry abrasive blasting may not remove all of the sulfide from the bottom of corrosion pits. Wet abrasive blasting is more effective than dry abrasive blasting b
47、ut complete removal of sulfide may not be achieved. After blast cleaning, contaminated sutfaces may be washed with dilute acid to remove sulfide. Acid treatment removes sulfide from the sutface by volatilization to H2S gas. SAFETY NOTE: Follow precautions when H2S is liberated. Sulfide removal metho
48、ds that have proved useful include: (a) Dry abrasive blast cleaning in accordance with NACE No. I/SSPC“-SP 57 followed by a 10 to 15% hydrochloric acid wash, fresh water rinse until neutral pH is achieved, dry, and a final dry abrasive blast cleaning in accordance with NACE No. l/SSPC-SP 5. Other ac
49、ids, such as acetic, citric, and phosphoric acids, have been used in place of hydrochloric acid; (b) Wet abrasive blast cleaning (abrasive plus water), dry, and a final dry abrasive blast cleaning in accordance with NACE NO. l/SSPC-SP 5. (c) Steam cleaning (for up to several days) with venting, fresh water wash, dry, and a final dry abrasive blast cleaning in accordance with NACE No. l/SSPC-SP 5. 5.3 Production equipment previously used in salt water or brine service may contain chloride contamination. Coating over chloride-contaminated steel may cause blistering and subsequent premature
