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Collaborating Authors
CORROSION 2004
ABSTRACT This paper will cover the evolution of offshore systems over the past 20-25 years, starting with the use of zinc and vinyl or chlorinated rubber systems, and moving to the currently used high solids systems. Consideration will be given to all the key regions of offshore production, including Gulf of Mexico, North Sea, Arabian Gulf and Asian fields, and how different construction processes, and arguably environmental conditions, drove a divergence of specifications which may now be converging again. The strengths and weaknesses of various systems will be reviewed in terms of both New Construction and Maintenance. Finally, the painting of Floating Production Facilities (e.g. FPSOs) will be considered, and how painting specifications for these have had to diverge from traditional approaches because of vastly different construction processes when compared to fixed platforms. INTRODUCTION In the Offshore Coatings Industry, as with most things in life, it is easy to view the past through rose tinted spectacles. It is not unusual to hear a lament that there were no where near as many problems with systems applied 20-30 years ago and that such systems gave longer lifetimes. This paper attempts to review where we have come from in terms of Offshore Coatings Systems, how this has evolved in various regions, why changes became necessary, and how these were addressed.
- North America > United States (1.00)
- Europe > United Kingdom > North Sea (0.26)
- Europe > Norway > North Sea (0.26)
- (2 more...)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.69)
- North America > Cuba > Gulf of Mexico (0.89)
- Europe > United Kingdom > North Sea (0.89)
- Europe > Norway > North Sea (0.89)
- (2 more...)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
ABSTRACT For both safety and environmental reasons, external protection of burned bullet tanks and above ground storage tank bottoms is now at the top of our industry?s worldwide priorities. To protect these buried structures it is essential to provide efficient cathodic protection systems, combined with external coatings. In fact, regulations in many countries now require the use of both active and passive protection. Cathodic protection for these buried structures presents a real challenge due to the large and complex geometries involved and the proximity of the anodes to the target structure. This paper details new design criteria for protecting these structures and providing a more efficient engineered solution that will ensure long-term corrosion-free service. It also discusses the field performance assessment of polymeric anode systems installed on both above ground storage tanks and LPG bullet tanks that have been in service for more than five years. INTRODUCTION Above ground storage tank (AST) bottom plates are usually coated on the soil-side and then welded together until the entire tank bottom is assembled. An effective cathodic protection system must be installed for the following reasons: (1) The heat of welding will destroy the coating in the vicinity of the welds, leaving, these now unprotected areas in contact with the soil and in a place where they cannot be repaired; (2) Welding can cause differences in the microstructure of the steel plate, with preferential corrosion possibly occurring at the heat-affected zones (HAZ) of the base metal near welds. This type of corrosion can cause significant localized metal loss1; (3) The remaining areas of undamaged coating cannot be relied upon to fully protect the bottomplate for its desired lifetime. This is due to normal coating breakdown over time, as well as the impossibility of gaining access to repair such coating defects. Applying a good quality, external, anti-corrosion coating to the bottom plates will significantly reduce the total CP current requirement and greatly extend the lifetime of the tank. Since the coating will have to perform over many years, it is best to use a high performance material such as fusionbonded epoxy or a solvent-free, liquid epoxy, applied to a minimum thickness of 350 microns.
- North America > United States (0.47)
- Asia > Middle East (0.47)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Processing Systems and Design > Tanks and storage systems (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers (1.00)
ABSTRACT The combination of an excellent protective coating system with a compatible cathodic protection system is required to adequately protect onshore and offshore pipelines. Excellent preparation of the pipeline substrate, combined with excellent coating application principles must be achieved in a pipeline coating plant in order that pipelines can be protected. INTRODUCTION Inadequate specifications, non-tested coatings, incorrect application principles, the use of incorrectly qualified personnel, bad construction practices etc. can all lead to the failure of pipeline protective coatings in-ground and in-sea. However, many pipeline protective coating failures still occur due to inadequate surface preparation criteria and techniques. The paper discusses the plant surface preparation of pipes, and the plant application of protective coatings to pipes. The possible consequences of not specifying and/or achieving the correct degree of preparation of the substrate are discussed. Case studies of modern pipeline protective coating failures, from around the world, are outlined CASE STUDIES Case studies presented are from work undertaken in South America, North Africa, India, the UK, Iran, USA, and Scandinavia. Case study I - South America Very high daytime temperatures and heavy afternoon precipitation were experienced where the pipe was stored. In addition the atmosphere and the ground both exhibited a high degree of "chloride content". The temporary "protectives" applied at both the pipe manufacturing works proved to be a major source of problems. The shellac type of material was thin and brittle and tended to loose adhesion to the pipes. However it remained over about 30% of the surface. This caused differential rates of corrosion over the 15 months of storage and consequently problems in the abrasive blast cleaning processes. The bitumen temporary "protective" softened and flowed to form raised areas on the pipes. A higher degree of corrosion was experienced next to these areas.
- Europe (1.00)
- North America > United States (0.66)
- Asia > Middle East > Iran (0.25)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT Onshore gas transmission lines are conjointly protected against external corrosion by cathodic protection (CP) and organic coatings. A coating may present defects such as holidays, rock indentation and/or disbondment. Those defects can generate a significant corrosion risk the lines. The experiments hereby presented have concentrated on the evaluation of the coating defects permeation to cathodic protection electrical currents and corrosive species (water and O2). Two electrochemical cells were designed to simulate coating defects. The first cells allowed the simulation of holidays and rock indentation; the second one, the simulation of large disbonded area with the possibility of electrolyte circulation in the gap. The cell also allows the control of the medium in an external compartment (simulating soil conditions) and monitor the medium evolution in the gap, containing a metallic coupon (simulating a coating disbonding). The metal potential, the oxygen concentration, and the pH of the medium under the coating disbondment were monitored using micro electrodes. In some instances weight loss or electrochemical measurement were carried out to assess the corrosion rate. The results are discussed with respect to the effect of the type of defect on the corrosion risk and in the case of the second cell, the effect of electrolyte circulation in the gap. The comparison between the different defect types shows significant differences which must be taken into account for a proper corrosion prevention of aging lines by cathodic protection. Therefore, this paper points out which types of defects are the most dangerous and must be detected to prevent corrosion risks. INTRODUCTION Onshore gas transmission lines are conjointly protected against external corrosion by cathodic protection (CP) and organic coatings. From the beginning of the sixties to the eighties,on GDF transmission networks, bituminous and coal tar enamels were used without proper distinction. Later on, 2 layers and then 3 layers polyethylene were used. As those coatings are aging (and even since the pipe has been laid), their protective properties may decrease. The appearance of defects such as micro-cracks, porosity, disbonding, may affect the coating protectiveness. Earlier studies 1, 2, 3 using field collected coating samples (coal tar or asphalt enamels) have revealed that although most of the time both electrical and chemical permeability did not decrease significantly with time, in certain circumstances their properties decay induces a corrosion risk.
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT The internal vessel and tank lining program for a state-owned Middle East Oil Company was reviewed. A revision in the strategy for selection, application, and maintenance of applied internal linings was suggested. Several major changes to current practices were recommended. First, qualification testing for specific products should replace the generic chemistry recommendations for vessel and tank linings. Second, a qualified coating inspector should be present for all phases of an internal coating job rather than relying on strict adherence to written standards. Third, more thorough record keeping for all tank and vessel coatings would enable better tracking of field performance of specific coating products. INTRODUCTION The use of organic coatings inside oilfield production vessels is extensive, but not without problems. One major Middle East Oil Company had numerous coating failures that led to a decision to install stainless steel clad vessels in a number of locations. Coating failures such as these should have been preventable, if a suitable coating material is selected and if it is applied correctly to a properly prepared surface. The cost of clad vessels was found to be as high as six times that of a standard carbon steel vessel, so coatings can provide an attractive, cost-effective alternative. A study was undertaken to examine how the company?s standard practices in the use of internal tank and vessel linings could be improved. A comprehensive review of all aspects of the vessel coating program had to consider not only the service requirements, but also had to take into account the current practices with regard to specifications and application procedures, inspection and materials selection.
- Africa > Middle East > Libya > Murzuq District > Murzuq Basin > Block NC 186 > Field A Field > Silurian Tanezzuft Formation (0.99)
- Africa > Middle East > Libya > Murzuq District > Murzuq Basin > Block NC 115 > Field B Field > Silurian Tanezzuft Formation (0.99)
- Africa > Middle East > Libya > Murzuq District > Murzuq Basin > Block NC 115 > Field A Field > Silurian Tanezzuft Formation (0.99)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT Online monitoring of carbon steel corrosion under different commercial coatings was conducted, utilizing coupled multielectrode sensors. The experimental results showed that the coupled multielectrode corrosion sensor is an effective tool for detecting initial defects and real-time degradation of the coatings. Because of their high sensitivity, the coupled multielectrode sensors may also be used as a quick and convenient tool for optimizing the selection of proper coatings for different applications. INTRODUCTION Coatings are used to prevent metallic substrates from corrosion in many industries?including infrastructure, transportation, military, and industrial process equipment. In the United States alone, the total annual cost of coating applications in 1997 was estimated to be between $33.5 billion and $167.5 billion, according to a recent NACE report.1 The corrosion protection provided by the coatings depends on the quality of the coatings. If the coating is deteriorated or damaged in a given environment, corrosion may take place under the coating or at the flawed location. Such corrosion can cause severe problems?even catastrophic failures?if it is not identified and mitigated at an early stage. Because corrosion beneath a coating is not easily detected, an effective monitoring technique is required to detect it at an early stage, in order to eradicate or control the undercoat corrosion. Periodically, inspection tools, such as holiday detectors, are used to evaluate the coating on a metallic substrate. An online monitoring technique may provide a real-time indication of the coating performance and serve as an early warning of degradation. Therefore, an online corrosion monitor is an ideal tool for detecting and controlling undercoat corrosion. Coupled multielectrode corrosion sensors have been used as in situ or online monitors for Non-uniform and localized corrosions, in laboratories and industrial applications.2-5 These applications have demonstrated that the sensors can be used to continuously monitor corrosion, not only in aqueous solutions, but also under solid deposits, such as bio-deposits and salt deposits.3,4 . In this study, coupled multielectrode corrosion sensors and a newly developed Multielectrode Corrosion Analyzer System were used as an online monitor to detect corrosions under coatings. The detailed experimental setup is described. The results of corrosion measurements on carbon steel under different coatings are presented.
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Information Technology > Architecture > Real Time Systems (0.55)
- Information Technology > System Monitoring (0.55)
ABSTRACT For many years a traditional approach to provide corrosion protection for exterior steel applications has been the application of two coats of epoxy followed by a high performance two-part aliphatic polyurethane. The latter is used because epoxies do not have good color and gloss retentive properties. Other limitations of this traditional approach arise from the coating's dew point and relative humidity restrictions as well as occasional concerns due to free isocyanates in the polyurethane finish. This paper describes a new two or three coat epoxy coating system specifically developed to overcome all these limitations without compromising corrosion protection or aesthetics. The areas of use for this new technology are offshore and marine environments, pulp and paper mills, food processing plants, and other wet or dry environments. It consists of an ultra-high solids epoxy primer that optimizes adhesion even on damp metal substrates or wet coatings; a mid coat epoxy for optional film-build depending upon the severity of the service environment; and a unique high color and gloss retentive UV stable epoxy with the aesthetic properties of a good quality aliphatic polyurethane finish. INTRODUCTION Typically most conventional epoxies cannot be applied on damp substrates without detrimental effects and thus it is important that the substrate be dry prior to application of most epoxies. To achieve the necessary dry conditions can be a costly proposition, especially in highly humid environments or where hydroblasting is used as a method of surface preparation. If the temperature falls below the dew point the substrate will invariably have water on the surface which, in most cases, must be dried prior to coating application. Two-part aliphatic polyurethanes also have dew point restrictions. They cannot be applied on damp or wet surfaces and are limited to a maximum 85% relative humidity restriction. Two new high performance epoxies have been developed that respectively address lesser surface preparation and aesthetics. The first epoxy (Epoxy WT) is an ultra-high solids epoxy that is better applied using airless spray equipment than with conventional spray equipment. The second epoxy (Epoxy UVS) provides high gloss and color retention. The majority of epoxies do not have good color and gloss retention that is why they are often topcoated with aliphatic polyurethanes. This novel UV stable epoxy is solvented and typically applied using conventional equipment. The scope of this paper is to focus primarily on a comparison of the UV stable Epoxy and the two-part high performance polyurethane (PUR) applied over an Epoxy WT. Potential uses for this new high performance system (which can be applied to wet surfaces and have excellent corrosion and gloss and color retention properties) include the following: pulp and paper plants, food processing plants, and areas where abrasive blasting cannot be used because of a potential spark hazard, such as oil refineries and chemical plants.
- Materials > Paper & Forest Products (0.75)
- Materials > Chemicals > Commodity Chemicals (0.49)
- Energy > Oil & Gas > Downstream (0.34)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.89)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.75)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.75)
ABSTRACT A new, surface tolerant Fusion Bond Epoxy (FBE) pipe coating is developed to tolerate a wider steel surface temperature window of 2 0 0 - 240 °C. Six Sigma methodology was used for the product development. The performance of this new generation of coating is compared to more conventional coatings. A trial at a pipe coating facility where the performance of the new coating was evaluated with a number of different surface conditions is described. INTRODUCTION When a new formulation is required to give enhanced performance, a traditional approach is to evaluate a wide range of formulations under standard conditions and commercialize the product as soon as a formulation meets the required performance criteria and has an acceptable cost. Design of Experiments (DOE) can be used when formulating to optimise the formulation. Six Sigma has been widely used in DuPont for business improvement; in this project Six Sigma was used for product development. This involved using a combination of DOE with statistical analysis. This project involved identifying the formulation parameters that have the most impact on the performance, i.e. those that affect the adhesion of the FBE to the steel. Once these were identified, a DOE was run to optimise the formulation. Statistical comparisons of products were conducted to confirm that there was an improvement in performance. The final, validation phase involved testing to confirm that the results seen in the lab were reproduced at a coating plant. Our aim was to develop a product that would be more surface tolerant and higher performance, one that would give improved performance when applied to surfaces that had received less than ideal cleaning (such as surfaces that were blasted but not rinsed with phosphoric acid), or were not pre- heated to an optimum temperature. In particular, we desired a product that could be applied over wider temperature ranges than conventional FBEs and still give acceptable performance. Also, we aimed to produce a product which gave higher performance than a conventional FBE when applied to a well prepared substrate. Resistance to disbondment was identified as a key requirement, our aim was to develop a product that gave a significant improvement in cathodic disbondment performance over conventional FBEs. Effect of Application Temperature on Adhesion During the formulation phase, the effect of application temperature on performance was analyzed since we desired a product with a wide application temperature window. Therefore when a new type of formulation was discovered that gave improved adhesion, the effect of application temperature on cathodic disbondment performance was examined by applying a conventional coating and the new formulation to lab. panels that were blasted but not rinsed and had been pre-heated to a variety of temperatures (see Figure 1). The conventional formulation gave acceptable results; its performance was improved by application at a higher temperature (230 °C). This corresponds with previous industry experience when conventional FBE coatings are plant applied 1. The new formulation gave much less disbondment than a conventional FBE and also gave less variation in disbondment over the temperature range we examined. The disbondment was essentially unchanged over this range, therefore this formulation met our requirement of being more surface tolerant, giving the same performance over an application temperature window of 205 to 230 °C. The post cure of the panels was changed depending on the lower application temperature to ensure full cure. A 3 minute p
- Energy (0.47)
- Materials > Chemicals > Commodity Chemicals (0.34)