Hydrogen combines with carbon within the alloy and forms methane. Hydrogeninduced cracking an overview sciencedirect topics. Hydrogeninduced cracking of steels under wet hydrogen sulfide environment j. Hydrogen induced cracking hic is wet h2s cracking in steel in the form of blisters or blister cracks. The terms stepwise cracking swc, hydrogen pressure cracking, blister cracking, and. Hydrogen induced cracking of pipeline and pressure vessel. Hydrogeninduced cracking hic is still a challenging issue that requires. Hydrogen induced cracking is generally considered as a complex problem involving hydrogen transport to susceptible sites, e. Petroleum refining processes are the chemical engineering processes and other facilities used in petroleum refineries also referred to as oil refineries to transform crude oil into useful products such as liquefied petroleum gas lpg, gasoline or petrol, kerosene, jet fuel, diesel oil and fuel oils refineries are very large industrial complexes that involve many different processing units. These gases are regarded as the primary sources of the internal corrosion of production tubing, transportation pipelines, and sometimes subsequent process equipment. Cracking, in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts. Hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. A detailed survey of hydrogen induced cracking hic was conducted in a saudi gas oil separation plant gosp.
A detailed assessment study was conducted in this plant pertaining to hydrogen induced cracking hic. Hydrogen sulfide hsub 2s has long been associated with the cause of corrosion damage and sulfide stress cracking ssc in high strength steels and high hardness weldments used in oil and gas production, petroleum refining, and petrochemicalchemical processing. Since not all aspects of the corrosion process of steel in sour gas environments are. It involves atomic hydrogen, which is the smallest atom, that diffuses into a metallic structure. The rate of cracking and the end products are strongly. Investigation of oil and natural gas pipelines failure by hydrogen. This process creates a high pressure and provides the basis for starting hydrogen induced cracks. Hic test apparatus is supplied with essential spares for uninterrupted long term testing. Ansinaceiso mr0103hd2010, materials resistant to sulfide stress cracking in corrosive petroleum refining environments available for download this nace standard establishes material requirements for resistance to sulfide stress cracking ssc in sour refinery process environments, i. According to this theory, hydrogeninduced cracking occurs in five steps as follows corresponding to the detailed hic mechanisms shown in figure 1 7, 8 hydrogen solubility and hydrogen diffuses in. Analysis of hydrogen induced cracking by insitu hic observation.
A saudi aramco gas processing plant commissioned in 1980 to process wet sour. Corrosionpedia what is hydrogeninduced cracking hic. Avoid burning through where the welding arc causes the pipe wall to be breached. The worlds energy consumption continues to increase steadily. Hydrogen induced cracking hic assessment in a gas processing.
While they succeeded in providing a small increase in gasoline yields, it was the commercialization of the fluid catalytic cracking process in. Regenerationcatalyst is reactivated by burning off coke. Moreover the rapidity of the stovepipe process allows a modification to this in using the quick application of the softening hot pass to become an integral part of the welding technique for avoiding root pass hydrogen cracking, but to the best of the authors knowledge this aspect has not been incorporated into a published prediction scheme. Reactionfeedstock reacts with catalyst and cracks into different hydrocarbons. The methane molecules create a pressure which leads. Largescale wet hydrogen sulfide cracking performance. Hydrogen for refineries is increasingly provided by.
Abstract a saudi aramco gas processing plant commissioned in 1980 to process wet sour gas streams and produce dry sweet sales gas in addition natural gas. One of the types of material damage that can occur as a result of hydrogen charging is sulfide stress cracking ssc of hard. Mechanical properties and hydrogen induced cracking. This accident highlights the need for greater care in commissioning hydrogen systems.
The piping system was not originally fabricated using hic resistant steel and has been employed in wet sour crude and gas services for the last 24 years. Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process. Hydrogen induced cracking hic assessment in a gas processing plant case study mohammed a abufour, mohammad. Furthermore, many of the new sources of crude petroleum california, alaska, venezuela, and mexico have yielded heavier crude oils with higher. Hydrogen induced cracking hic is a common form of wet h2s cracking caused by the blistering of a metal due to a high concentration of hydrogen.
Metallographic examination identified the cracking as sulfide stress cracking ssc, stressoriented hydrogeninduced cracking sohic, and carbonate cracking. Damage can occur at temperatures between ambient and 300 degf. One of the types of material damage that can occur as a result of hydrogen charging is sulfide stress cracking ssc of hard weldments and microstructures, which is addressed by. Hydrogen sulfide when dissolved inwater is a weak acid, and therefore, it is a source of hydrogen ions. Crystallographic texture control helps improve pipeline. Fossil fuels oil, natural gas, and coal still comprise more than approximately 85% of the worlds energy consumption.
Inplant piping hydrogen induced cracking survey in a gas. Hydrogen sulphide cracking is a type atom cracking process that helps in breaking down hydrogen atoms from sulphur atoms in aqueous hydrogen sulphide, which is available in crude oil and natural gas. Metals are more susceptible to hydrogen induced cracking at higher temperatures which explains why it is usually started during the forming or finishing process of the metal. Defects hydrogen cracks in steels identification twi. Carefully commission hydrogen pipe chemical processing. Susceptibility to hydrogeninduced cracking of api 5l b and x52ms lowcarbon steels in nace 177a, 177b, and 284b solutions has been investigated by the present work.
When the process is done, a heavy, almost pure carbon residue is left coke. When dissolved in aqueous solutions, acid gases such as co 2 or h 2 s can be highly corrosive and have led to multiples failures and leakages in the oil and gas industry. Because the total amount of hydrogen demand is known, and onsite production in the refinery smrs can be derived from the surveyed natural gas. The cracking was primarily in the heataffected zone haz of weldments or the shell plate adjacent to this area. Initiation of stress corrosion cracking and hydrogeninduced. According to this theory, hydrogen induced cracking occurs in five steps as follows corresponding to the detailed hic mechanisms shown in figure 1 7, 8 hydrogen solubility and hydrogen diffuses in. Catalysts include zeolite, aluminum hydrosilicate, bauxite and. Hic usually occurs due to the effects of aqueous hydrogen charging of steel in wet h2s refinery process environments. Particular attention was given to largescale behavior vs behavior for smallscale laboratory test specimens under an applied tensile stress. These internal cracks may propagate by a process called hydrogeninduced cracking hic or hydrogen blistering. Subsea valves, which are mainly ball or through conduit gate valves, are located on the trees and wellheads and designed based on api and iso standards. Hic can be prevented, or even reversed, through several process which focus on ensuring that no. These units produced small quantities of unstable naphthas and large amounts of byproduct coke.
Hydrogen induced cracking of hard materials zthe refining industry has had very few cases of hydrogen related cracking in pure hydrogen service. Hydrogen bakeouts are applied for driving this out of steel, since the trapped one can lead to weld cracking or an entire vessel including cold cracking, delayed cracking, hydrogen induced cracking, hydrogen assisted cracking and hydrogen embrittlement. Petroleum refining petroleum refining catalytic cracking. Guidelines for production of api pipelines steels suitable. The boltloaded specimen was subjected to both acid and electrochemical cell environments in order to produce hydrogen. There are ndt techniques focused on identifying, measuring and tracking hic, but total focusing method tfm has shown to be generally the preferred technique. The paper looks at the problem of hydrogen cracking both in general fabrication and with particular reference to. Published by welding technology institute of australia wtia, silverwater, nsw, australia, 1999. Hic can be prevented, or even reversed, through several process which focus on ensuring that no contact is made between the metal and hydrogen. Ind november, 1976 combined effect of temper and hydrogen embrittlement on threshold for hydrogeninduced fracture in crmo steels. To understand better the mechanism of the crack initiation process, key. General requirements for the purchase of pipes for use in oil and gas industries. It involves the ingress of hydrogen into a component, an event that can seriously reduce the ductility and loadbearing capacity, cause cracking and catastrophic brittle failures at stresses below the yield stress of susceptible materials. No external stress on test specimens is usually required to examine this type of cracking.
Corrosion standard tests of carbon steels to be used in oil and gas production. Hughes 1880 note on some effects produced by the immersion of steel and iron wires in acidulated water. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carboncarbon bonds in the precursors. F are least susceptible to hydrogen induced cracking as compared to the other weld specimens. The presence of hydrogen atoms in a metal degrades some of its mechanical properties, especially its ductility, leading in some cases to embrittlement. The principal distinguishing feature of this type of crack is that it occurs in ferritic steels, most often immediately on welding or a short time after welding. Offshore oil field development and operation began by using platforms and ships, but oil producers and operators are looking for new and innovative ways to reduce production costs and improve recovery and. Although h2s is not corrosive by itself, it becomes a severely corrosive agent in the presence of water,leading to pipeline embrittlement. Hic test, hydrogen induced cracking test, step wise cracking. Mechanical properties and hydrogen induced cracking behaviour. Initiation of stress corrosion cracking and hydrogeninduced cracking in oil and gas. There are three basic functions in all catalytic cracking processes. A comparative study of hydrogeninduced cracking resistances.
Hydrogen induced cracking tests were conducted on high strength steels and nickeliron base alloys using the constant displacement boltloaded compact specimen. The term hydrogen induced cracking hic has been widely used for describing cracking of. This nace standard establishes material requirements for resistance to sulfide stress cracking ssc in sour refinery process environments, i. Cracking induced by hydrogen in the presence of h2s has been researched extensively, and practical guidelines have been developed for steels used in production and pipelining. It is intended to be used by refineries, equipment manufacturers, engineering contractors, and.
Additionally, hydrogen atoms diffuse through metals and coalesce. Eia surveys petroleum refineries and provides estimates of net hydrogen demand at the refinery, natural gas feedstock used to produce hydrogen, and hydrogen production capacity on an annual basis. Petroleum refining petroleum refining visbreaking, thermal cracking, and coking. Hydrogen induced cracking tests of high strength steels. Pipelines and piping systems which contain petroleum, petroleum products, or fuel gases that may be pressurized andor flowing. Hydrogen sulphide gas is a poisonous gas and cannot be emitted into the environment without treatment, thus hydrogen sulphide cracking process has. Hic damage is a common degradation mechanism in the oil and gas industry.
Hydrogen induced cracking hic remains a prominent issue for oil and gas. Catalytic uses a catalyst to speed up the cracking reaction. Jun 03, 2018 hydrogeninduced cracking hic refers to the internal cracks brought about by material trapped in budding hydrogen atoms. Hydrogen cracking its causes, costs and future occurrence. A comparative study of hydrogeninduced cracking resistances of. All weld specimens exhibit fine ferriticbainitic with small inclusions of pearlite. Petroleum and natural gas industriesmaterials for use in. Api rp 579, fitnessforservice, american petroleum institute, washington, d. The use of thermal cracking units to convert gas oils into naphtha dates from before 1920. In the case of a crystal lattice becoming saturated or coming into contact with atomic hydrogen, many alloys and metals may. Weld specimen f3ra and f19ra have a higher susceptibility to hydrogen induced cracking as compared to the other weld specimens.
Jun 11, 2014 this accident highlights the need for greater care in commissioning hydrogen systems. Photo courtesy phillips petroleum company catalysts used in catalytic cracking or reforming. Susceptibility to hydrogen induced cracking of api 5l b and x52ms lowcarbon steels in nace 177a, 177b, and 284b solutions has been investigated by the present work. The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. Hydrogen induced cracking hic assessment in a gas processing plant. Hydrogen cracking may also be called cold cracking or delayed cracking. The blistering damage tends to form parallel to the surface and to the direction of hoop stress. The steps of a possible mechanism of hydrogeninduced cracking hic can be. Petroleum refining visbreaking, thermal cracking, and coking. Nace standard tm 02842003, evaluation of pipeline and pressure vessel steels for resistance to hydrogeninduced cracking. Corrosion products were characterized by scanning electron microscopy and xray dispersive energy spectrometry, which were. Schematic diagram of a fluid catalytic cracking unit. The term hydrogeninduced cracking hic has been widely used for describing cracking of.
Hic test, hydrogen induced cracking test, step wise. Abstract hydrogen induced cracking hic is one of the major issues of line. We can also provide hydrogen plant operation overthefencesupply, maintenance and repair and emergency supply arrangement to ensure that your business is working at its optimum. Weld metal hydrogen cracking in pipeline girth welds, proc. Under particular conditions, the atomic hydrogen is able to diffuse into the metal equipment. Is there an industry acronym or abbreviation weve missed.
Chemical processing how oil refining works howstuffworks. Proceedings of the 2010 8th international pipeline conference. These internal cracks may propagate by a process called hydrogen induced cracking hic or hydrogen blistering. Hic test specimens are machined with thickness of 530mm, width 20mm, and length of 100mm is suitable for testing as per the nace standard. They are made in exotic corrosionresistant alloys to avoid different types of corrosion such as hydrogen induced stress cracking, and should withstand highpressure classes. Cracking is the most important process for the commercial production of gasoline and diesel fuel. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carbon carbon bonds in the precursors. Hydrogeninduced cracking hic is most commonly encountered in steels but other metals are susceptible, as shown in table 33.
A saudi aramco gas processing plant commissioned in 1980 to process wet sour gas streams and produce dry sweet sales gas in addition natural gas liquid ngl. Johnson 1875 on some remarkable changes produced in iron and steels by the action of hydrogen acids. Since world war ii the demand for light products e. Guidelines for production of api pipelines steels suitable for hydrogen induced cracking hic service applications. A metallographic analysis of these steels was performed before and after nace tm0284 standard testing. Inplant piping hydrogen induced cracking survey in a gas oil. Asme stppt006, design guidelines for hydrogen piping and pipelines. Hydrogen induced cracking in microalloyed steels directory. In petro chemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carboncarbon bonds in the precursors. Cracking of petroleum yields light oils corresponding to gasoline, middlerange oils used in diesel fuel, residual heavy oils, a solid carbonaceous product known as coke, and such gases as methane, ethane, ethylene, propane, propylene, and butylene. Hydrogen induced cracking test apparatus is rectangular provided with ready to use connections fittings. Depending on the end product, the oils can go directly into fuel blending, or they can be routed through further cracking reactions or other. In this issue, the characteristic features and principal causes of hydrogen cracks are described. This is a type of deterioration which can be linked to corrosion and corrosioncontrol processes.