Wet hydrogen sulfide h2s cracking inspectioneering. This paper analyzed the hsla pipeline steels stress corrosion behavior and mechanism which tested in the saturated solution of h2s. It is appreciated that a material used in an h2s corrosive medium can suffer sulfide stress cracking ssc, a form of hydrogen embrittlement cracking occurring in h2s environments. Actuator sizing, standards and specifications for floating. The gas can cause severe stress cracking of steel and other metals. It can lead to unexpected sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. Sulfide stress cracking how is sulfide stress cracking abbreviated. Sulfide stress cracking ssc was first identified and the mechanism outlined in the 1940s after several failures of oil and gas systems in texas and canada. But when they failed they failed catastrophically and sometimes repeated failures occurred. Ian sutton, in plant design and operations second edition, 2017. When they are in good working order, they deliver fuel to meet the evergrowing demand for energy around the world. Scc stress corrosion cracking scc da stress corrosion cracking direct assessment sga southern gas association sme subject matter expert smys specified minimum yield strength sp standard practice srb sulfatereducing bacteria ssaw single submerged arc weld ssc sulfide stress cracking ut ultrasonic testing. Sulfide stress cracking an overview sciencedirect topics.
The steels sscc susceptibility was determined by constant load tensile according to nace tm0177 standard. Sulfide stress cracking is also called hydrogen sulfide cracking, sulfide cracking, sulfide corrosion cracking and sulfide stress corrosion cracking. Sulfide stress cracking of highstrength steels is a problem in handling sour hydrogen sulfide containing crude oil or natural gas. Stress corrosion cracking led to pipeline rupture in prince george.
In this respect, the behavior in sour environment of the constitutive steels is an important parameter. The flixborough explosion was the largestever peacetime explosion in the uk. This term should not be confused with stress corrosion cracking scs, since this is anodic in nature. Is sulfide stress cracking an anodic or a cathodic process.
Standard material requirements materials resistant to sulfide. Specialized stress corrosion cracking testing capabilities. Sulfide stress cracking resistant drill pipe addresses h2s challenges. There are maximum acceptable h 2 s concentration limits in sale quality oil and gas, which require. Standard material requirements sulfide stress cracking resistant metallic materials for oilfield equipment contents 1. Environmental cracking in line pipe carrying sour product. Sulfide stress cracking is the worst type of corrosion in the presence of hydrogen sulfide. Initiation of stress corrosion cracking and hydrogeninduced cracking in oil and gas linepipe steels.
As shown in figure 11, corrosion has been responsible for 18 percent of the significant incidents both. Field observations and laboratory data have indicated that the stress corrosion cracking of composite tubes occurs predominantly during the boiler shutdown. Standard material requirements materials resistant to. Litigation support includes supervising laboratory testing, simulations, corrosion damage investigation, preparing. Scc is highly chemically specific in that certain alloys are likely to undergo scc only when exposed to a small number of chemical environments.
After the hydrotest, the next stage is to dry the pipeline to ensure that no water remains on the internal pipe wall or at low spots along the pipe route. February 19, 2017 by mariano iannuzzi in a previous post, we discussed the broad differences between anodic and cathodic forms of environmentally assisted cracking eac. Oct 24, 20 sulfide stress cracking resistant drill pipe addresses h2s challenges. No matter how well these pipelines are designed, constructed and protected, once in place they are subjected to environmental abuse, external damage, coating disbondments, inherent mill defects, soil movementsinstability and third party damage. Sulfide stress crackingresistant drill pipe addresses h2s. When placed in proximity to tensile stresses, embrittlement and the beginnings of brittle fracture may occur. Amine cracking typically occurs on the surface and the cracks are usually radially. Jul 25, 2017 most of the early failures were associated with sulfide stress cracking ssc, at the time a relatively new phenomenon. Corrosion investigation of pipeline steel in hydrogen.
H 2 s can cause sulfide stress cracking of stainless steels. Biaxial stress corrosion cracking frames capable of conducting testing in aggressive environments, such as brines with co 2 and h 2 s. The influence of chemical composition and microstructure of api linepipe steels on hydrogen induced cracking and sulfide stress corrosion cracking. Stress corrosion cracking scc a particularly detrimental form of pipeline corrosion is known as stress corrosion cracking scc.
Balon valves contain grease and are not suitable for oxygen service due to an increased risk of combustion or explosion. An explosion and fire in 2018 along an enbridge inc natural gas pipeline in northern british columbia was caused by normal stress that. Amine cracking is a form of stress corrosion cracking, which is related to alkaline and carbonate stress corrosion cracking. Summary sulfide stress cracking ssc is just one of several forms of hydrogen. Sulfide stress cracking is the cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide a form of hydrogen stress cracking. The article also introduces a quantitative criterion to determine the maximum allowable defect size based on fracture mechanics principles. Strain and sulfide stress cracking in pipeline girth welds. Materials and corrosion trends in offshore and subsea oil and. Used sem observed the fracture, and then the steels corrosion rate and shortterm corrosion behavior were analyzed by electrochemical polarization.
In this chapter the terms eac and scc are generally interchangeable. Liquid releases resulting in an unintentional fire or explosion. This article describes current industry practices to catalog features observed after sulfide stress cracking testing. In the gas phase, a stream is sour if the h2s partial pressure exceeds 0. However, in some cases reported as 10 to 20 percent in canada scc also occurs in the circumferential direction cscc when the predominant stress is an axial stress, such as stresses developed in response to pipe. Chapter 1 pipeline corrosion november 2008 page 1 1 introduction. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as corrosion byproducts. Sulfide stress cracking nace mr01752002, mr0175iso 15156. Sulfide stress cracking is a form of hydrogen embrittlement that occurs in highstrength steels and in localized hard zones in weldment of susceptible materials when the environment contains wet h 2 s. Sulfide stress corrosion cracking and hydrogen induced cracking of a216wcc wellhead flow control valve body article pdf available in case studies in engineering failure analysis. The major hazards of h 2 s are its ability to cause rapid damage to health or sudden death due to accidental exposure and metal integrity failure due to general corrosion or cracking. Sulphide stress cracking is prevented by minimising the hardness and strength of the.
The explosion caused a 35metre long, ninemetre deep crater after the pipeline was ejected from the ground, and the ruptured ends of the pipeline showed signs of tearing and heat exposure, the. Dec 19, 2019 sulfide stress cracking ssc is a type of hydrogen cracking which presents a cathodic embrittlement mechanism. This standard nace mr0175iso 15156 addresses all mechanisms of cracking that can be caused by h2s, including below cracking conditions. Hydrogen sulfide burns with a blue flame to form sulfur dioxide which is. Sulfide stress crackingresistant drill pipe addresses h2s challenges. By implementing the requirements of the regulation and through responsible maintenance programs, pipeline operators continuously inspect their pipelines for indications of scc. One of the corrosive environments under scrutiny is the stagnant floor water rich in sulfide and hydroxide due to their high solubility, which may form on the boiler floor during shutdown. Among the most prone to sulfide stress cracking include valve trim, blowout preventer hard parts and tool joints. Experimental study of gas explosions in hydrogen sulfide. Be observant for signs of pipeline damage, leakage, or security concerns.
Pdf sulfide stress corrosion cracking and hydrogen. Pipeline failure rates from stress corrosion cracking. Home which alloy is best to resist sulfide stress cracking and stress. Sulfide stress cracking mostly occurs in very highly acidic environments. Sulfide stress cracking oil and gas pipelines wiley online library. Sulfide stress cracking is also called hydrogen sulfide cracking, sulfide cracking, sulfide corrosion cracking and. Pdf with the development of the natural gas industry, gas transmission pipelines have been developed rapidly in terms of safety, economy.
Corrosion is related to the susceptibility of the material to the environment, while stresses may be residual, external. In order to ensure smooth and uninterrupted flow of oil and gas to the end users, it is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the lines and their component fittings would undergo material degradations due to corrosion. Aug 14, 20 carneiro r a, ratnapuli r c and lins v f c l. Explains why pipeline stress corrosion cracking happens and how it can be prevented. No matter how well these pipelines are designed, constructed and protected, once in place they are subjected to environmental abuse, external damage, coating disbondments, inherent mill. Hydrogen cracking its causes, costs and future occurrence p h m hart weld metal hydrogen cracking in pipeline girth welds, proc. Stress corrosion cracking scc is the growth of crack formation in a corrosive environment. Hydrogen sulfide stress corrosion cracking in materials. Which alloy is for sulfide stress and stress corrosion. Hydrogen sulfide is a colorless, very poisonous, flammable gas with the characteristic foul odor of rotten eggs. Pipeline scc creates weaknesses at points in the pipe, which in turn makes the pipe more susceptible to third party damage, overpressure events, etc.
Scc occurs as a result of a combination between corrosion and tensile stress. There were 28 fatalities as well as the near complete destruction of the nypro plant in north lincolnshire by blast and then fire. Sulfide stress cracking how is sulfide stress cracking. Sulfide stress cracking ssc is a form of hydrogen embrittlement which is a cathodic cracking mechanism. Investigations of hydrogen embrittlement and sulfide stress cracking of nickel and nickelbase alloys have not been quite as extensive as in the case of steels. Standard material requirements sulfide stress cracking. These cracks are not visible initially, but as time passes, these individual cracks may grow and forms colonies, and many of them join together to form longer cracks. The catastrophic explosion at flixborough in june 1974 has been traced to the failure of a bypass. But, the presence of h 2 s in well fluids imposes severe restrictions on the use of tubular goods due to sulfide stress cracking phenomenon 2. Hydrogen cracking its causes, costs and future occurrence. Which alloy is best to resist sulfide stress cracking and stress corrosion cracking. Sulfide stress cracking ssc vs hydrogen induced cracking hlc posted in refining, hydrocarbons, oil, and gas. The pipeline rehabilitation and replacement costs are included in.
Metallurgy failure analysis and expert testimony introduction. Stress corrosion cracking led to a pipeline explosion near prince george two years ago, according to a transportation safety board investigation. Stress corrosion cracking scc is a type of environmentallyassisted cracking eac, or the formation of cracks caused by various factors combined with the environment surrounding the pipeline. Deficiencies in predicting the extent of cracking of the 36inch natural gas pipeline operated by westcoast energy inc. Hydrogen embrittlement characteristics, especially pertinent to sulfide stress cracking, or steels has been investigated to a great extent. Corrosion investigation of pipeline steel in hydrogen sulfide containing solutions. Donner summit, ca, pipeline leakinvestigated a diesel and gasoline pipeline leak that occurred in an environmentally sensitive area in the sierra mountains, near donner lake, and the role that external damage and subsequent stress corrosion cracking may have played in the leak. Sulfide stress cracking of pipelinecase history onepetro. Pdf sulfide stress corrosion cracking and hydrogen induced. Pdf stress corrosion cracking of gas pipeline steels of different. Jul 17, 2017 stress corrosion cracking in pipelines begins when small cracks develop on the external surface of buried pipelines.
This paper describes work performed under a short study programme into the sulfide stress corrosion cracking behaviour of samples taken from a pipe girth weld that were strained to conditions that simulated those of a typical pipe reeling and laying operation. For this reason, along with toxicity risks of hydrogen sulfide gas, it is essential that water muds be kept entirely free of soluble sulfides and especially hydrogen sulfide at low ph. Scc is defined as the brittle fracture of a normally ductile metal by the conjoint action of a specific corrosive environment and a tensile stress. Materials and corrosion trends in offshore and subsea oil. In one such instance the pipeline in the subject case gave a service life of about 12 years in sour gas service. Prepare and maintain core metallurgical, material, and quality control specifications for pipe. What is nace mr0175iso 15156 steel pipe and fittings.
H2s can cause sulfide stress cracking of stainless steels. Scc cracking is usually oriented longitudinally in response to the hoop stress of the pipe, which is usually the dominant stress component resulting from the internal pressure. Most of the early failures were associated with sulfide stress cracking ssc, at the time a relatively new phenomenon. Hydrogen sulfide is an extremely toxic, flammable gas that may be encountered in the production of gas well gas, highsulfide, high sulfur content crude oil, crude oil fractions, associated gas, and waters. As we know that both form of cracking are due to the absorption of atomic hydrogen that is produced by. The pipeline operator had a stress corrosion cracking hazard management plan in place for this pipeline. Stress corrosion fact sheet pipeline risk management. Sulfide stress cracking is a function of hydrogen sulfide concentration as low as ppm, hydrogen sulfide partial pressure, stresses, material yield strength, temperature and ph. Hic and ssc behavior of highstrength pipeline steels. Stress corrosion cracking found to be cause of 2018 pipeline. Saeid kakooei, hossein taheri, mokhtar che ismail and abolghasem dolati, 2012.
Since hydrogen sulfide is heavier than air, it can collect in low places. Environmentally assisted cracking eac is a general term that includes processes such as stress corrosion cracking scc, hydrogen embrittlement he, sulfide stress cracking ssc, liquid metal embrittlement lme, and corrosion fatigue cf. Ssc is a form of spontaneous brittle breakdown in occurring in highstrength alloys and steels when it comes in contact with humid hydrogen sulfide as well as sulfidic atmospheres. Safety, reliability and risks associated with water, oil and gas pipelines, pluvinage, g. Which alloy is for sulfide stress and stress corrosion cracking. Sulfide stress cracking ssc of high strength, low alloy steel is a phenomenon of particular. Stress corrosion cracking led to 2018 pipeline explosion near prince. Corrosion problems during oil and gas production and its.
Sulfide stress cracking nace mr01752002, mr0175iso. Test frames for applying cyclic loads with the measurement of crack propagation rates. Stress, corrosion caused 2018 enbridge gas pipeline blast reuters. What causes stress corrosion cracking in pipelines. Corrosion, stress cracking to blame for prince george pipeline fire in. Corrosion investigation of pipeline steel in hydrogen sulfide. This is a complex topic, other factors, such as ph, chloride concentration, and temperature also affect the potential for steel cracking. Amine cracking is often intertwined with wet hydrogen sulfide h 2 s and carbonate cracking, as amines, carbonates and wet sulfides often exist together in amine treating systems. Sulfide stress cracking ssc occurs at locations where atomic hydrogen is able to diffuse at sites of high internal stress, such as grain boundaries, inclusions and regions of triaxial stress at notches. An experimental study of turbulent combustion of hydrogen sulfide h 2 s and natural gas was performed to provide reference data for verification of cfd codes and direct comparison. Sulfide stress cracking ssc stress corrosion cracking.
In this study, hydrogeninduced cracking hic and sulfide stress corrosion cracking ssc behaviors of highstrength pipeline steels in four different strength grades x70, x80, x90 and x100 with the microstructure of acicular ferrite were estimated. Stress corrosion cracking led to pipeline rupture in. Micro alloyed pipeline steels are commonly used in the petroleum industry for transport applications 1. Sulfide stress cracking nace mr01752002, mr0175iso 15156 651 te c h n i c a l new sulfide stress cracking standard for refineries don bush, principal engineer materials, at emerson process management fisher valves, is a member and former chair of a nace task group that has written a document for refinery applications, nace mr0103. Sulfide stress cracking, resistant metallic material for oil field equipment nace materials are optional and must be specified on purchase orders ce marking to the ped available on most products warning. Corrosionpedia what is sulfide stress cracking ssc. Sulfide stress crackingnace mr01752002, mr0175iso 15156 651 te c h n i c a l new sulfide stress cracking standard for refineries don bush, principal engineer materials, at emerson process management fisher valves, is a member and former chair of a nace task group that has written a document for refinery applications, nace mr0103. Sep 27, 20 in order to ensure smooth and uninterrupted flow of oil and gas to the end users, it is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the lines and their component fittings would undergo material degradations due to corrosion. Sulfide stress cracking ssc vs hydrogen induced cracking. In year 2012 the pipeline failed suddenly by cracking along the heat affected zone of the spiral weld. It should not be confused with the term stress corrosion cracking which is an anodic cracking mechanism. Sulfide stress cracking and corrosion fatigue of steels. Hydrogen sulfide is present in most crude oil sources, and the explosion behaviour of pure h 2 s and mixtures with natural gas is important to address. The failure was classified as circumferential stress.