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Corrosion inhibition and management (including H2S and CO2)
ABSTRACT In a previous investigation, AC corrosion rate data generated from weight loss experiments was compared with the results from a model for AC corrosion that was developed using a modified Butler-Volmer approach. The model considered the anodic and cathodic Tafel slopes, diffusion limited oxygen transport, interfacial capacitance and solution resistance. Both experimental and model results highlighted the importance of the interfacial capacitance on the rate of AC corrosion, especially at a frequency of 60Hz. In the present work, an extension of this finding is presented to investigate the influence of scale formation on AC corrosion rates. Scale formation at a holiday in a pipeline coating, such as calcium deposits, carbonate deposits or corrosion product, changes the interfacial capacitance of the steel. Thus, steels in soils which are prone to the formation of these scales may have significant difference in AC corrosion rates for the equivalent AC current and pipe-to-soil potential. To investigate the influence of scale formation on AC corrosion behavior, the corrosion rate of carbon steel API grade X65 pipeline steel in a soil simulant solution (NS4) with and without calcium carbonate and iron carbonate scales and under cathodic protection potentials were studied. Using the proposed model for AC corrosion and within the context of scale capacitance, polarization resistance and solution resistance (as measured for the samples via electrochemical impedance spectroscopy) data were analyzed. The results of this work have implications on industry standards and the evaluation of AC corrosion rates in different soil types. INTRODUCTION AC interference can occur by conduction or induction mechanism where pipelines share right of way with some interference sources such as a high-voltage transmission line that is typically fed by 50 or 16.7 Hz frequency AC. Cathodic protection (CP) and other corrosion mitigation strategies to preserve the integrity of pipelines are reported to have failed in the presence of AC. For example, AC corrosion failures in France with CP On-potentials of -2 and -2.5 VCSE and five cases of failure in North America due to AC are a few case histories of AC corrosion failures in CP condition. This type of failure is a threat of catastrophic failure and there is a lack of well-agreed mitigation criteria for AC-induced corrosion. Unclear mechanism of AC corrosion is the main reason for the uncertainty on the CP criteria in the presence of AC interference.
- Research Report > Experimental Study (0.66)
- Research Report > New Finding (0.46)
- 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 Metal matrix composite (MMC) and nanocomposite coatings are being proposed as alternatives to their monolithic counterparts to improve protection against wear in chemically-aggressive environments. Corrosion resistance of MMC coatings is strongly dependent on the coating microstructure, which is affected by the physical and chemical nature of the dispersed particles, as well as the particle concentration. In this paper, we present the results of our tests on the corrosion response of Ni-P MMC coatings with micro-crystalline and nano-crystalline diamond as the dispersed phase. Potentiodynamic and electrochemical impedance spectroscopy tests were performed to compare the corrosion of Ni-P composites and nanocomposites, and the results are analyzed in terms of their microstructures. The corrosion potential is primarily determined by the P content and the heat treatment carried out after deposition, and is weakly dependent on the particle content. In low-P coatings, the presence of micrometer-size particles has no significant impact on Ecorr and Icorr. Heat treatment increases Ecorr and decreases Icorr. Similar trends are observed in the high-P coatings. EIS results suggest self-healing behavior with some microstructures. INTRODUCTION Electroless nickel coatings have been widely used in industrial applications over the past five decades due to their unique characteristics such as uniformity of deposition as well as corrosion, abrasion and wear resistance. Contrary to electroplating, the electroless process is an autocatalytic method in which reduction of metallic Ni ions in solution occurs through the oxidation of a reducing agent in solution, and due to this autocatalytic nature, it produces highly conformal coatings. Electroless processes are used to produce Ni-P, Ni-B or pure Ni depending on the reducing agent used: hypophosphite, borohydride or dialkyl amino borane and hydrazine [1, 2]. The properties of Ni-P and Ni-B coatings are to a great extent determined by the content of P or B and by the heat treatment that follows the deposition. More recently, electroless processes have also been used to prepare Ni-metal matrix composite (MMC) coatings [1-3] and said coatings are being considered for many applications in the Oil and Gas industry [4]. During the process of deposition, the MMC coatings are formed by the impingement of particles and ions on the surface. Dielectric particles do not provide surfaces for the autocatalytic reduction of the Ni ions and therefore particle envelopment is expected to occur by growth from the conducting matrix.
- 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)
The corrosion problems associated with process vessels and process pipework are complex. Before one can assess which high performance linings may be utilized, a full understanding of the complete process is required.
- Europe (0.94)
- North America > United States > Texas > Harris County > Houston (0.16)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.69)
- Energy > Oil & Gas > Downstream (0.69)
- 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 > Pipelines, Flowlines and Risers > Piping design and simulation (0.87)
ABSTRACT Service life and design life estimates are quickly converging for many transmission and distribution assets. Replacement costs have escalated due to new constraints that were not considered in early days of developing the power grid. As a consequence, the maintenance funds must be optimized to maximize results of the life extension methods. This may be achieved by modeling the margins between operating loads and the structure conditions to study the impact of the ranking criteria on population distributions. Ranking criteria is needed to understand levels of degradation which may require a host of actions from doing nothing up to structural repairs, Aligning the mitigation methods efficacy and cost with the ranking criteria then provides an understanding of the balance between risk and cost for the asset's total life cycle. This report provides an approach to understanding the significance of reject and ranking criteria and how they may become a barrier to good asset management or a path to improving system reliability and grid resiliency. Introduction Times were different in 1907 when a farmer could choose between purchasing a new windmill or a cast iron wood stove for nearly the same price. The radio had just been invented by Marconi, Judson invented the zipper, Baekeland invented Bakelite and Fleming invented the first vacuum tube. The PanAmerican Exposition had just been held in Buffalo, New York and the centerpiece was the Electric Tower with “Illumination that was the most brilliant and elaborate ever contemplated”. The American standard of living was increasing with more disposable income than ever before and the public wanted these wonderful new inventions. To satisfy this need, visionaries such as Thomas Edison and his competitor George Westinghouse were busy expanding the first electric power delivery systems required to deliver these promising changes to homes and businesses all across the country. Past In their infancy, construction standards for utility structures were less well defined at the turn of the century. Often structures were either custom-built by hand in the field or simply adapted from other applications; a good example is the windmill tower available from the Sears & Roebuck catalog, and retrofitted with crossarms and insulators before stringing (see Figure 1).
- North America > United States > New York > Erie County > Buffalo (0.24)
- Asia > Middle East > Israel > Mediterranean Sea (0.24)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Power Industry (1.00)
- Banking & Finance (1.00)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.97)
- (3 more...)
ABSTRACT AC power transport system expansion has increased the risk of AC in transmission pipelines and awareness of pipeline integrity engineers. Several works have proven the detrimental effect of AC current on pipeline safety and corrosion of - pipelines. AC may be imposed on pipelines independently or in combination of three coupling mechanisms described as being resistive capacitive and inductive. However, only resistive and inductive coupling mechanisms promote AC corrosion during pipeline operation. In resistive coupling, the presence of a short circuit in the AC power due to a lighting strike or a steady state current leakage may discharge current on a nearby pipeline, increasing the pipe to soil voltage, coating stress, and likelihood of electric shock hazard at above grade pipeline appurtenance. In inductive coupling, the magnetic field produced around the power conductors generates an electrical field along a parallel pipeline, inducing a voltage that can impact CP effectiveness and promote corrosion. On this work, calculations of induced AC voltage and current are performed for multiple scenarios which take into account important factors such as: HVAC transmission powerline configuration, lateral distance to the transmission pipeline, and parallelism between the transmission lines, soil, and pipeline and coating properties. In addition, a parametric analysis was performed based on sensitivity analysis of the factors to identify locations with higher AC corrosion susceptibility. INTRODUCTION Enbridge operates the world's longest and most complex crude oil and liquids transportation system, having approximately 25,000 km (15 500 miles) of pipeline throughout North America. The organization has grown significantly over the past decade and its rapid expansion has introduced new challenges. Multiple pipelines run across or in parallel with HVAC transmission powerlines which can create a considerable electromagnetic coupling between the structures. In addition, the increasing energy demand has resulted in increment 60 Hz AC transmission corridors and subsequently exposed pipelines to higher levels of induced voltages.
- North America > Canada (0.29)
- North America > United States > Texas (0.19)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Offshore pipelines (0.66)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.53)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.48)
Optimization of CP Design with Consideration of Temperature Variation for Offshore Structure
Sung Hong∗, Min (Hyundai Heavy Industries Co., Ltd.) | Kim, Jin Ho (Hyundai Heavy Industries Co., Ltd.) | Park, Kyung Jin (Hyundai Heavy Industries Co., Ltd.) | Hwang, Jong Hyun (Hyundai Heavy Industries Co., Ltd.)
ABSTRACT Temperature effect on cathodic protection (CP) design current density was examined by electrochemical tests, and a case study of optimized CP design for the FPSO (Floating Production Storage and Offloading) using a computational analysis tool was performed. Electrochemical test results showed the specimen (EH36) in 28 °C had the lower current density and higher resistance than that of 5 °C. It was because of calcareous deposit which was verified by surface analysis using SEM and EDS. Computational analysis results showed that the structure in 5 °C didn't satisfy the CP criteria at the bottom shell and mooring chain. The structure at 28 °C satisfied the protective potential range, however, unstable enough to predict corrosion damage. To optimize and resolve the problems, the CP design was changed. Consequently, the structure at 5 °C is sufficient to satisfy the protective potential criteria at bottom shell and mooring chain. In the case of 28 °C, a more even potential distribution is achieved. INTRODUCTION Increasing energy consumption leads to building a large number of offshore platforms, pipelines, ships, and underwater storage. These steel structures are exposed to seawater in various environments from tropical to arctic climatic regions, so the corrosion deterioration has to be significantly concerned. In this reason, recently, the importance of cathodic protection (CP) which is one of the protection methods against corrosion is being gradually highlighted with a demand for long lasting design life of offshore structure in the various environments. Cathodic protection (CP) has been used as a primary method to control the corrosion of metal in conjunction with organic coating. It can reduce corrosion rate, and a properly maintained system will provide protection in accordance with the designed life of the structure. Currently, the importance of CP is being gradually highlighted with a demand for longer lasting design life of offshore structures so that the long-term electrochemical performance of CP becomes a key concern to ensure structural integrity. There are two basic types of CP systems: impressed current CP (ICCP) and sacrificial anode CP (SACP). The ICCP system has a power supply (rectifier), which is used to generate larger potential differences between anode and structure, permitting more current to flow to the structure being protected. In the SACP system, the anodes have more negative potential than the protected structure. When they are connected in seawater, the galvanic current flows from the anode (relatively negative potential) to the protective structure (relatively positive potential) in a DC circuit. They do not require an outside power source to operate, so sacrificial anodes have few limited in their use. Generally, the offshore structure is designed to prevent corrosion by sacrificial anode.
- 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 > Floating production systems (1.00)
ABSTRACT Crack growth rate (CGR) behavior of UNS N07718 was investigated as a function of K-rate in two different environments under cathodic potentials, a mild environment containing 3.5wt% NaCl and a more aggressive environment containing 0.5M H2SO4. The CGR in 3.5wt% NaCl at -1050mV SCE exhibited a plateau CGR that was a strong function of K-rate. CGR measurements in sulfuric acid exhibited K dependence. The CGR exhibited a weak dependence on K-rate in sulfuric acid. In the sulfuric acid environment stable cracking was sustained at constant displacement, which was not readily observed in the 3.5wt% NaCl at -1050mV SCE. A test was performed to understand the fatigue crack growth rate behavior under gentle cycling at two different values of Kmax in 3.5wt% NaCl/pH = 8.2 at -1050 mV SCE. The measured fatigue crack growth rate increased as the frequency was decreased from 1 mHz to 0.01 mHz. The measured CGR at 1mHz with 86400s hold periods at a Kmax of 55MPa vm and 66MPavm was significantly lower than the CGR values measured in the rising displacement tests at the same K values. This suggested that crack tip strain rate may play a critical role in sustaining static crack growth. INTRODUCTION A fracture mechanics based approach is currently being pursued for subsea equipment design by the Oil and Gas (O&G) industry in High Pressure High Temperature (HPHT) applications. A significant driver for this shift in the industry is due to the very high pressures (>15ksi) and temperatures (>350°F) that are expected in future Gulf of Mexico (GoM) fields. The start-up period of a well is typically associated with an increase in pressure and temperature in the subsea components. The pressure increases from a low value to the full operating pressure of the well as it is brought on line. The increase in pressure in the subsea equipment usually occurs over a relatively short period of time on the order of tens of minutes to hours. The temperature of the various components increases from the seabed temperature of about 40°F to the operating temperature of about 350°F to 400°F. The rise in temperature usually lags the pressure increase and occurs over the course of a few days. This is typically followed by long periods at nominally constant pressure and temperature associated with normal operating conditions prior to the next shutdown and start-up sequence. API 17TR8 Annex D (Material Characterization Protocols) is currently being finalized to develop guidelines on the use of metallic materials (high strength corrosion resistant alloys (CRA's) and low alloy steels) for HPHT applications. The document suggests that there is currently a need to develop fatigue and fracture data for the materials of interest in not only production environments but also in seawater under cathodic protection environments. There has to date been very limited fatigue and fracture data generated under conditions relevant to subsea HPHT design.
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > HP/HT reservoirs (0.94)
- Well Completion > Hydraulic Fracturing (0.86)
ABSTRACT Additive manufacturing (AM), commonly referred to as 3D printing, offers advantages compared to more traditional production methods including quick prototyping, short production runs and intricate, thin section, microfluidic, variable composition and low-waste designs. These exciting features are accompanied by new challenges including higher costs, the possibility of variable quality and inherently anisotropic properties, etc. To utilize the benefits of AM in sour service environments, new qualification and materials testing requirements will be necessary. There are possible corollaries envisioned for the application of AM to sour service with the (additive) technique of welding. In this work, the relative SSC resistance of UNS S17400 stainless steel produced by AM (powder bed fusion) was compared with welded and wrought parts of the same alloy utilizing NACE TM0177 Method A. The chemistry, microstructure, mechanical properties (including hardness), and electrochemical behavior of these materials were examined to explain the results observed and to seek predictors for AM suitability for sour service. The overall goal was to determine if a set of AM parts could comply with the testing requirements of wrought or welded materials for sour service as outlined in NACE MR0175 / ISO 15156-3:2015. Recommendations for a qualification pathway for AM parts in sour service are included. INTRODUCTION Usage Additive manufacturing (AM), commonly referred to as 3D printing, offers advantages compared to more traditional production methods including quick prototyping, short production runs and intricate, thin section, microfluidic, variable composition and low-waste designs. These exciting features are accompanied by new challenges including higher costs, the possibility of variable quality and inherently anisotropic properties, etc. To utilize the benefits of AM in sour service environments, new qualification and materials testing requirements will be required. There are possible corollaries envisioned for the application of AM to sour service with other processes already included within NACE MR0175 / ISO 15156-3:2015, especially the (additive) technique of welding. NACE MR0 1 75 Part 3 is primarily a document of the sour service capability of wrought and cast material types. Cast materials can add a new dimension to wrought material issues due to the coarse grain structure and control of heat transfer on solidification that can often negatively affect mechanical and corrosion performance. Cast material CB7Cu-1 is of particular interest for the cast materials because it is essentially the same composition as the material of interest in this study. HIP/Powder metals are briefly addressed, namely UNS S31803 and UNS N07626 with additional hardness limits (S31803) or additional hardness, tensile strength and aging requirements (N07626). These materials have additional complications related to feedstock, oxidation, porosity, etc.
- Machinery > Industrial Machinery (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Metals & Mining > Steel (0.67)
The Effect of Hydrogen on Plain and Notched Test Specimens of Precipitation Hardenable Nickel Alloys
McCoy, S. A. (Special Metals Corporation) | Maitra, D. (Special Metals Corporation) | Mannan, S. K. (Special Metals Corporation) | Crum, J. R. (Special Metals Corporation) | Tassen, C. S. (Special Metals Corporation)
ABSTRACT High strength Nickel alloys are widely used in subsea and downhole O&G applications for their excellent combination of mechanical properties, toughness and corrosion resistance in sour environments. The trend in the O&G industry is for using higher strength materials for high pressure – high temperature service, however as strength increases materials may also become more susceptible to ambient temperature failure mechanisms associated with hydrogen absorption. In recent years resistance to Hydrogen Stress Cracking (HSC) and Hydrogen Embrittlement as well as sour corrosion resistance have become of increasing interest to the industry due to a number of reported failures of high strength precipitation hardened Nickel alloy grades used in completion tools. The failures of the materials have been attributed to unfavourable microstructures increasing their susceptibility to HSC. A number of factors are known to influence HSC and this paper reviews previous work and shows laboratory results using different test techniques to demonstrate the influence of yield strength and microstructure on the resistance to HSC of precipitation hardenable Nickel alloys N07718, N09925, N07725, N09945 and N09946. Tests have been conducted in a Hydrogen charging environment while conducting a slow strain rate test with plain and notched specimens and assessing the effect of hydrogen absorption on the materials' properties. The resistance of the Nickel alloys to HSC is correlated with material composition, microstructure and mechanical properties. The effect of a stress concentration is shown influence the notch tensile strength of the materials in a hydrogen charged environment. INTRODUCTION The Precipitation Hardenable Nickel alloy 718 (N07718) is widely used for critical downhole oil field applications such as high strength tubing hangers and completion equipment. The material is particularly useful in High Pressure/High Temperature wells where high strength and corrosion resistance are required in H2S containing production fluids. Over the last 15 years a limited number of field failure investigations in PH Nickel alloys have been related to the presence of sufficient amounts of intergranular delta phase precipitates promoting hydrogen embrittlement, which results in brittle cracking of alloy 718 and alloy 725. The investigations on these failures of Nickel Precipitation Hardenable (PH) alloy 718 have studied the potential for grain boundary precipitates to impair the materials resistance to hydrogen stress cracking by causing brittle fracture by decohesion at the particle/ matrix interface. Cassagne et al suggested that hydrogen embrittlement is promoted by any inter-granular second phase precipitate irrespective of chemical composition. Liu et al in a separate study on alloy UNS N07718 also showed local transgranular cleavages were initiated from the delta phase/ matrix interfaces in the presence of pre-charged hydrogen. Mannan et al has also shown that the presence of significant amounts of any second phase lowers time –to- failure, % elongation and reduction of area ratios for high temperature sour environment SSRT tests. In this investigation Slow Strain Rate (SSR) testing on plain and notched specimens at ambient temperatures in a Hydrogen charging environment have been used to show the effects of hydrogen on a range of high strength PH Nickel alloys mechanical properties.
- Well Completion (1.00)
- Reservoir Description and Dynamics (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
Evaluation of Anti-Fouling Surfaces for Prevention of Lead Sulfide Scaling in Single and Multiphase Conditions
Keogh, William (University of Leeds) | Charpentier, Thibaut (University of Leeds) | Neville, Anne (University of Leeds) | O'Brien, Andrew (University of Leeds) | Eroini, Violette (Statoil ASA) | Olsen, John Helge (Statoil ASA) | Nielsen, Frank Møller (Statoil ASA) | Ellingsen, Jon Arne (ConocoPhillips) | Bache, Oeystein (ConocoPhillips) | Baraka-Lokmane, Salima (Total)
ABSTRACT Formation of mineral scale is one of the primary complications affecting production in the oil and gas industry. Soured reservoirs contain hydrogen sulfide (H2S) that can prompt the formation of exotic sulfide scales, leading to detrimental fouling that negatively affects the production of oil and gas. The mode of precipitation and deposition of lead sulfide (PbS) scale on a variety of anti-fouling surfaces for potential application in oilfield systems is examined in this paper. Previous sulfide scale work has reacted H2S derived from sodium sulfide (Na2S) with lead chloride (PbCl2) brine. However, the design of a rig for implementation of H2S gas into a reaction vessel resulted in a more accurate simulation of the processes occurring within sour reservoirs. Multiphase conditions induced by introduction of a light oil phase within a turbulent emulsion were used to simulate the presence of crude oil within a production line prone to sulfide scaling. The results showed that the presence of a light oil phase within the system caused the homogeneously-precipitated lead sulfide to reside at the interface between the oil and water phases, increasing its propensity to adhere to surfaces and promoting the dominant adhesion process. The wettability of anti-fouling surfaces had a significant bearing on the degree of lead sulfide deposition in a multiphase system. INTRODUCTION Though less common than carbonate and sulfate scales, build-up and deposition of metal sulfide scales on downhole equipment and production tubing can negatively affect the flow and production of oil . Lead and zinc sulfide scaling has become a concern in a number of North Sea oil and gas fields, rich in both hydrogen sulfide (H2S) gas and metal ions Sulfide ore deposits of lead and zinc, known as Mississippi Valley Type (MVT) deposits, are commonly observed in Devonian to Permian and Cretaceous to Tertiary formations . As a result, cations of lead and zinc are found naturally in many formation waters in HT/HP fields due to mineral dissolution of these ores over millions of years. Sulfide ions (S), formed when hydrogen sulfide (H2S) gas present in the reservoir reacts with formation water, are extremely susceptible to forming sulfide scales with dissolved metal cations . Injected water used for pressure support can also enrich seawater with heavy metal ions from the formation . Evolution of H2S gas or 'souring' of reservoirs in the North Sea can occur through both microbiological and geochemical means; as a consequence of the activity of sulfate reducing bacteria (SRB) and chemical reactions resulting from seawater injection, respectively . equation equation
- North America > United States (1.00)
- Europe > United Kingdom > North Sea (0.45)
- Europe > Norway > North Sea (0.45)
- (6 more...)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)