Sulfide Stress Cracking Research Articles

Evaluation of Sulfide Stress Cracking Susceptibility of Welded Joints of Supermartensitic Stainless Steel Used in Oil Country Tubular Goods (OCTG)

Evaluation of Sulfide Stress Cracking Susceptibility of Welded Joints of Supermartensitic Stainless Steel Used in Oil Country Tubular Goods (OCTG)

Damage to Special-Purpose Ring Wavy Springs under the Influence of Hydrogen Sulfide-Containing Media

Annular wavy springs are widely used in the oil and gas industry and most often serve either as compensators for temperature deformations or for mechanical seals of various joints in equipment transporting oil and gas media. These springs provide high load capacity with a relatively low draft, which ensures a compact design. Most often, such springs are made by stamping from sheet steel. When operating technological equipment that transport hydrogen sulfide-containing oil and gas media, hydrogen sulfide stress corrosion cracking occurs quite often, which can lead to failure of industrial equipment. In particular, damage to annular wavy springs can cause depressurization of elements of industrial equipment and cause significant harm not only to the environment, but also to maintenance personnel. The object of research was annular wavy springs made of steel type X15N7M2YU. The purpose of the study is to determine the resistance of the spring material to stress corrosion cracking. This article discusses the test results of special purpose annular wavy springs in an aggressive hydrogen sulfide-containing medium artificially prepared according to the recommendations of ANSI/NACE TM 0177. The results of hardness studies, strength calculations and metallographic studies of damage to a wavy spring are presented. The chemical composition of the metal of the spring fully corresponds to the steel type X15N7M2YU declared by the enterprise. According to the studies conducted in environments containing hydrogen sulfide, the wavy spring is not recommended for use in oil and gas equipment, since it is not resistant to hydrogen sulfide cracking under stress.

Corrosion Evaluation and Mechanism Research of AISI 8630 Steel in Offshore Oil and Gas Environments.

In this study, we optimized the traditional composition of AISI 8630 steel and evaluated its corrosion resistance through a series of tests. We conducted corrosion tests in a 3.5% NaCl solution and performed a 720 h fixed-load tensile test in accordance with the NACE TM-0177-2016 standard to assess sulfide stress corrosion cracking (SSCC). To analyze the corrosion products and the structure of the corrosion film, we employed X-ray diffraction and transmission electron microscopy. The corrosion rate, characteristics of the corrosion products, structure of the corrosion film, and corrosion resistance mechanism of the material were investigated. The results indicate that the optimized AISI 8630 material demonstrates excellent corrosion resistance. After 720 h of exposure, the primary corrosion products were identified as chromium oxide, copper sulfide, iron oxide, and iron-nickel sulfide. The corrosion film exhibited a three-layer structure: the innermost layer with a thickness of 200-300 nm contained higher concentrations of alloying elements and formed a dense, cohesive rust layer that hindered the diffusion of oxygen and chloride ions, thus enhancing corrosion resistance. The middle layer was thicker and less rich in alloying elements, while the outer layer, approximately 300-400 nm thick, was relatively loose.

The fracture and perforation failure analysis of downhole tubes

：The downhole tubes were fractured and perforated after 5 years of shut-in due to high water cuts. This study employs a comprehensive array of analytical techniques to investigate the mechanisms behind fractures and perforations. Utilizing non-destructive testing (NDT), direct reading spectrometer, tensile strength testing machine, impact testing machine, optical microscope (OM), macroscopic fracture morphology observation, scanning electron microscope (SEM) and energy spectrum analysis (EDS), and sulfide stress corrosion cracking (SSCC) was studied. The reason for the fracture of the tubing is that under the condition of low pH value, high hydrogen sulfide environment, the tubing is fractured due to stress concentration caused by cracks in the outer thread relief groove. The perforation of the inner tube wall was caused by gradual wall thickness reduction under the influence of H2S, CO2, and Cl−, resulting in fouling and eventual perforation. To prevent tube corrosion during long-term shut-in, it is recommended to inject crude oil or diesel into the well.

A phase field finite element study and evaluation of sulfide stress cracking in DCB specimen testing

The challenges presented by sour environments rich in hydrogen sulfide (H2S) underscore the necessity for a comprehensive understanding of material behavior under such conditions. The cracking susceptibility of metals and alloys used for subsurface equipment in downhole oil and gas exploration operations is particularly concerning. The NACE Double Cantilever Beam (DCB) test has emerged as a widely used quality assurance tool in the petroleum industry, leveraging fracture mechanics principles to assess the environment-assisted cracking (EAC) resistance of metals and alloys. The DCB test evaluates the fracture toughness KISSC of materials in H2S-containing environments via assessment of the crack arrest, which serves as a vital parameter in structural integrity assessments to mitigate the risk of service-related failures from sulfide stress cracking (SSC). However, various studies suggest that different test parameters, such as arm displacement and initial notch, significantly influence KISSC. This work presents a detailed numerical investigation on a comprehensive simulation of the DCB test, examining the effects of different test parameters on KISSC prediction. A coupled deformation-diffusion phase field framework is adopted to simulate SSC in DCB specimens arising from a complex interplay between material deformation, hydrogen diffusion, and fracture. The numerical results show good agreement with experimental results reported in the literature and provide deeper insights into the factors affecting crack growth and arrest in DCB testing.

Sulfide stress corrosion cracking in L360QS pipelines: A comprehensive failure analysis and implications for natural gas transportation safety

This research investigates the severe weld failures in L360QS pipelines, which are integral to the infrastructure of high-pressure natural gas transportation systems. Even with strict compliance to engineering standards, two pivotal welds experienced sulfide stress corrosion cracking (SSCC) due to continuous exposure to hydrogen sulfide and stresses from construction activities. A comprehensive material analysis and stress simulation has been utilized, revealing a maximum stress concentration of 544.9 MPa that surpasses the yield strength of the pipeline material. This discovery prompts a reevaluation of current safety margins and underscores the urgent need for enhanced pipeline integrity management. Our findings, corroborated by stress distribution simulations, not only illuminate the complex interplay of material properties and environmental factors in SSCC but also provide a new perspective for the safe service of pipeline.

DEFORMATION MECHANISMS IN CASE OF DESTRUCTION OF THE TUBING NOZZLE MADE OF FERRITE-PEARLITE STEEL

In the work by methods of experimental studies and computer modeling, deformation mechanisms were analyzed during the destruction of the steel suspended branch pipe of the tubing. Tubing rupture occurred during production well operation for 306 days as a result of hydrogen sulfide stress corrosion cracking (SSCC), which was preceded by hydrogen embrittlement of the metal and cyclic action of external forces. Scanning electron microscopy (SEM) shows that the suspended branch pipe is characterized by a ferrite-pearlite structure, and in the area of its fracture, which occurred in the threaded part, there is an increased content of degenerated pearlite grains and traces of hydrogen blisters. Analysis of the crystallographic texture of the original nozzle showed the presence of Br {110} < 112 >, G {110} < 001 >, TG1 {111} < 110 >, TG2 {111} < 011 >, RG {110} < 110 > and RC {001} < 110 > grain texture components. It was found that after operation of the nozzle in well conditions, in the area far from the fracture, the grain orientations related to Cube {001} < 100 >, TG1 {111} < 110 >, TG2 {111} < 011 >, TB3 {331} < 136 > texture components increase. It was found that in the fracture area, in addition to the grain orientations characteristic of the nozzle body, there are also Br {110} < 112 >, G {110} < 001 >, RC {001} < 110 >, RG {110} < 110 >, TC {112} < 110 >, TB1 {111} < 112 > and TB2 {554} < 225 > texture components It is shown that Cube and grain orientation TB3 in the branch pipe after operation accelerate the process of hydrogen embrittlement of metal, and the presence of TB1 orientation indicates the process of return and/or recrystallization in the product. It was found that the process of hydrogen embrittlement led to a decrease in the strength properties and ductility of the steel of the branch pipe. Within the framework of viscoplastic self-consistent (VPCC) model, textures and deformation behavior of samples cut from different sections of the nozzle (before and after operation) were simulated. It was found that at the initial stages of tension the samples of the new branch pipe, the most active is the operation of {110} < 111 > slip systems. In samples of the nozzle after operation, the activity of {110} < 111 > slip systems decreases. At the same time, the activity of {123} < 111 > slip systems increases, and the nature of the operation < 112 > {111} of the slip system does not change. It was found that in all studied states before destruction the activity of {123} < 111 > systems increases ~ 1.4 times. It was concluded that the growth of TG2 {111} < 011 >, {332} < 110 > and {557} < 110 > texture components, as well as the activity of < 123 > {111} slip systems are associated with the effect of shear deformations that generate microcracks in pearlitic grains, and the applied forces contribute to the development of cracks and subsequent destruction of the product. It has been shown that by controlling the crystallographic texture and, accordingly, deformation mechanisms, it is possible to produce new pipeline steels that are more resistant to SSCC.

Sulphide Stress Corrosion Cracking of ASTM A516 Grade 70 Steel Covered with Austenitic and Martensitic Stainless-Steel Deposits

Sulphide Stress Corrosion Cracking of ASTM A516 Grade 70 Steel Covered with Austenitic and Martensitic Stainless-Steel Deposits

A Limited Evaluation of the Applicability of NACE MR0175/ISO 15156 H2S Limits to Supercritical CO2 Pipelines

In an earlier paper one of the authors raised the question of whether the hydrogen sulfide (H2S) partial pressure threshold of 0.05 psia (0.3 kPa) for cracking of steels from sulfide stress cracking is pertinent to dense phase carbon dioxide (CO2) systems in which there is no free gas phase. This paper presents a limited test of the pertinence of this threshold value in Supercritical CO2. Autoclave tests of four-point bend beam specimens of API 5L Grade X80 line pipe steel at 0.05 psia (0.3 kPa) and 0.20 psia (1.38 kPa) H2S were performed and the samples were examined after testing for cracking. In addition, the test conditions were modeled with the OLI Studio software to determine the H2S fugacities and H2S concentrations in the brine phase. No cracking was found after 30 d of exposure.

RESISTANCE OF FERRITE-PERLITE STEEL TUBING BRANCH PIPE METAL TO DESTRUCTION IN HYDROGEN SULFIDE MEDIUM

This paper discusses the problems of resistance of the metal of the tubing branch pipe (tubing) to the process of its destruction in a medium containing hydrogen sulfide and when exposed to external forces. A 73х73 tubing nozzle made of 38G2SFA steel was selected as the material for research. The tubing fragment was destroyed during production well operation. To establish the reasons for the failure of the tubing nozzle, a visual inspection was carried out, tests were performed to assess the hardness and mechanical properties, the microstructure and microtexture of the metal were analyzed using scanning electron microscopy (SEM) methods. To analyze the nature of the distribution of introduced defects, the mutual orientation of structural components and crystallographic texture, studies were carried out by the method electron backscatter diffraction (EBSD). Studies of the suspended branch pipe, which does not have chemical protection, showed that the cause of its destruction was hydrogen sulfide stress corrosion cracking (SSCC) as a result of hydrogen embrittlement and the action of external tensile forces exceeding the yield strength of the metal. It was established that as a result of the interaction of hydrogen sulfide of the distilled product with the metal of the branch pipe, hydrogen embrittlement of the material of the branch pipe occurred. The process of hydrogen embrittlement of the fragment was proved by detecting hydrogen blisters in the metal microstructure and establishing the process of coalescence of neighboring inclusions. In addition, the results of the test to measure the hardness of the metal along the wall thickness further supported the hypothesis of hydrogen embrittlement of the tubing. EBSD analysis showed that the threaded part of the branch pipe is characterized by a small size of structural elements and an increased density of introduced defects (geometrically necessary dislocations), which are a promising site for the deposition of molecular hydrogen. It is concluded that reaching the limit concentration of molecular hydrogen reduces the binding energy of metal atoms and this process initiates the formation of pores. It has been established that the development of cracks along large-angle grain boundaries is facilitated, and small-angle and coincidence site lattice (Σ3, Σ5, Σ11 and Σ13b) grain boundaries are active barriers to crack propagation. It has been shown that by optimizing the elemental composition of steel, controlling the microstructure, crystallographic texture, as well as the type and state of grain boundaries, new pipeline steels can be produced that are more resistant to SSCC.

Regulating the partially mixed zone via post-weld heat treatment to enhance sulfide stress corrosion cracking resistance of the Inconel 625/X80 weld overlay

This paper investigated the effect of post-weld heat treatment (PWHT) on microstructure evolution and sulfide stress corrosion cracking (SSCC) behavior of the fusion boundary (FB) region of Inconel 625/X80 weld overlay, with a focus on the partially mixed zone (PMZ). Three heat treatment regimens were designed, namely 620 °C/10 h, 620 °C/20 h, and 670 °C/10 h, in which 620 °C/20 h was proved to be the optimal parameter. The 10-hour PWHT conditions might induce heterogeneous carbon distribution owing to insufficient tempering duration, exacerbating the hardness mismatch in the FB region and thus promoting the development of SSCC. Following the 620 °C/20 h treatment, most of the brittle phase with high hardness in the FB region was eliminated, reducing the nucleation site for SSCC. More importantly, martensite in the PMZ was transformed into austenite with rod morphology, while cementite adjacent to the PMZ might evolve into dispersed refined austenite. Austenite shows low hydrogen sensitivity, enhancing the SSCC resistance of the PMZ. On the other hand, the carbides in the X80 matrix might restrict the diffusion of hydrogen toward the PMZ, thereby reducing the susceptibility of the PMZ to SSCC.

Failure Causes Analysis of Circumferential Cracking on Gathering Pipeline in M Oil and Gas Field

The gathering and transportation pipeline experienced corrosion cracking failure after 2 years of operation. This paper conducted an analysis on the reasons for the pipeline failure by integrating background information on its usage, as well as observations, analyses, and detection of the morphology of failure samples. The results indicated that the fracture originated from the inner wall of the pipeline and extended to the outer wall along the wall thickness until complete fracture occurred. Based on microstructure analysis of the fracture and original microcracks at the top of the pipeline, it was determined that the fracture was a multi-source brittle fracture, spreading in both inter-granular and trans-granular forms with obvious radial quasi-cleavage fractures accompanied by secondary cracks. EDS analysis revealed that the element S was present in all zones related to fracture initiation, spreading, and transient zones. XRD analysis showed that corrosion products on the fracture surface were mainly composed of FeS, indicating the presence of H2S in the service environment leading to sulfide stress corrosion cracking characteristics in line with pipeline failure. It is recommended to confirm the source of H2S in the service medium and test residual stress within the same pipeline for potential risk assessment regarding cracking in other areas.

Features of the formation of niobium-rich carbide phases in the melt and their effect on the resistance of high-strength casing pipes to sulfide stress corrosion cracking

Features of the formation of niobium-rich carbide phases in the melt and their effect on the resistance of high-strength casing pipes to sulfide stress corrosion cracking

Improvement of sulfide stress corrosion cracking resistance of the Inconel 625/X80 weld overlay by post-weld heat treatment

Improvement of sulfide stress corrosion cracking resistance of the Inconel 625/X80 weld overlay by post-weld heat treatment

Evaluation of the “nickel effect” in sulfide stress cracking of low alloy steels

The “nickel effect” refers to the cause of the 1 wt %Ni maximum limit in low alloy steels for the oil and gas production industry to avoid sulfide stress cracking (SSC). The Ni restriction dates to the first edition of the NACE MR 0175/ISO 15156 standard in 1975 and the specific reasons for that limitation remain disputed. This work evaluates the nickel effect with electrochemical tests in the presence and absence of tensile loads at anodic and cathodic potentials and at the open circuit potential (OCP). Thiosulfate was used as a satisfactory alternative to H2S bubbling. The effect of nickel on hydrogen transport and trapping was analyzed with gaseous hydrogen permeation tests. A strong influence of Ni, even at Ni contents below 1 wt%, on SSC initiation at OCP due to trench formation was observed. Compared to other common alloying elements, Ni had a modest role in hydrogen trapping.

Experimental studies of the influence of hydrogen and sulfur on sulfide-corrosion destruction under tension of pipelines

For the first time, comprehensive experimental studies of the influence of hydrogen and sulfur on sulphide stress corrosion cracking (SCR) of pipe steels in a corrosive-aggressive environment of NACE were carried out. In the research, experimental steels of the 06G2BA and 08KHMCHA brands, which are widely used in the construction of pipelines for various purposes, were used an analytical system (analyzer of non-stationary processes – ANP) was developed and tested in laboratory conditions, into which the installation for tests on corrosion-mechanical cracking under stress was integrated. For the first time, comprehensive experimental studies of pipe steel samples of grades 06G2BA and 08KHMCHA under the influence of sulfur and hydrogen were carried out, which made it possible to develop an understanding of the mechanisms of SCDS (sulphide-corrosion destruction under stress) and HID (hydrogen-initiated destruction). For the first time, experimental studies of the corrosion kinetics of 06G2BA and 08KHMCHA steels were carried out depending on the duration of the tests in the NACE model environment, while three periods of the formation of corrosion products were determined. It was found that sulfur and hydrogen, which are dissolved in test pipe steels, have a strong influence on the growth rate of corrosion cracks of SCDS, which made it possible to determine the optimal content of sulfur and hydrogen in steel 06G2BA. It is shown on the basis of the results of experimental studies that to ensure high crack resistance of pipe steels under conditions of static and cyclic loads both in air and in conditions of corrosive-aggressive environments, the sulfur content should not exceed 0.015-0.020%, and the dissolved hydrogen content should not exceed 2-3 ppm . The obtained results make it possible to improve pipe steels in the process of their smelting at metallurgical enterprises thanks to the use of economical modification with niobium, chromium, cerium and other impurities, which contribute to the fragmentation of the structure and reduce the content of non-metallic inclusions and harmful impurities.

Simultaneous Enhancement of Strength and Sulfide Stress Cracking Resistance of Hot-Rolled Pressure Vessel Steel Q345 via a Quenching and Tempering Treatment.

Sulfide stress cracking (SSC) failure is a main concern for the pressure vessel steel Q345 used in harsh sour oil and gas environments containing hydrogen sulfide (H2S). Methods used to improve the strength of steel usually decrease their SSC resistance. In this work, a quenching and tempering (Q&T) processing method is proposed to provide higher strength combined with better SSC resistance for hot-rolled Q345 pressure vessel steel. Compared to the initial hot-rolled plates having a yield strength (YS) of ~372 MPa, the Q&T counterparts had a YS of ~463 MPa, achieving a remarkable improvement in the strength level. Meanwhile, there was a resulting SSC failure in the initial hot-rolled plates, which was not present in the Q&T counterparts. The SSC failure was not only determined by the strength. The carbon-rich zone, residual stress, and sensitive hardness in the banded structure largely determined the susceptibility to SSC failure. The mechanism of the property amelioration might be ascribed to microstructural modification by the Q&T processing. This work provides an approach to develop improved strength grades of SSC-resistant pressure vessel steels.

Corrosion Behavior and Mechanical Performance of Drill Pipe Steel in a CO2/H2S-Drilling-Fluid Environment

Objectives: This article investigates the corrosion behavior and mechanical-property changes of S135, G105, and V150 drill pipe materials in a high-temperature-resistant, potassium amino poly-sulfonate drilling fluid, which has good lubrication performance and contains CO2/H2S, by applying an 80% yield-limit-load simulation. The results show that the CO2-corrosion behavior of G105, S135, and V150 drill pipes are obvious under the simulated constant-load-stress-corrosion environments at the wellhead, well-middle, and bottomhole positions. Compared to uncorroded drill pipes, S135 and V150 drill pipes have increased strength and yield ratios, decreased fracture elongation, and increased sensitivity to hydrogen embrittlement under H2S action, and V150 has a greater risk of stress-hydrogen embrittlement. The strength and yield ratios of G105-material drill pipes decrease, while the fracture elongation increases; the intensity-change amplitude levels are ranked V150 > G105 > S135, and the fracture-elongation-change amplitude is ranked G105 > S135 > V150. The tensile-performance-change amplitude and the SSCC (Sulfide-Stress-Corrosion Cracking) sensitivity of G105 and V150 drill pipes were the highest at the bottomhole. S135 drill pipe materials were most affected by pitting and tensile action at the wellhead, and they had the with the largest SSCC sensitivity.

Microstructural Characterizations and Sulfide Stress Cracking Susceptibility of a High-Strength Oil Country Tubular Goods-Purpose Steel Under Different Quenching Conditions

Microstructural Characterizations and Sulfide Stress Cracking Susceptibility of a High-Strength Oil Country Tubular Goods-Purpose Steel Under Different Quenching Conditions

Addressing Hydrogen Sulfide Corrosion in Oil and Gas Industries: A Sustainable Perspective

In the oil and gas industry, the corrosion attributed to hydrogen sulfide (H2S) is one of the most significant challenges. This review paper systematically investigates the diverse facets of H2S corrosion, including its sources, corrosion locations, mechanisms, and resultant corrosion products. Understanding different forms of H2S corrosion, such as stress-oriented hydrogen-induced cracking (SO-HIC), sulfide stress cracking (SSC), and hydrogen-induced cracking (HIC), provides a thorough comprehension of these phenomena. The paper discusses critical factors influencing H2S corrosion, such as temperature, flow rate, pH, and H2S concentration, highlighting their implications for sustainable practices in the oil and gas sector. The review emphasizes the significance of monitoring and mitigation strategies, covering continuous monitoring, applying corrosion inhibitors, selecting materials, and conducting thorough data analysis and reporting. Furthermore, the role of training in fostering a sustainable approach to H2S corrosion management is highlighted. This exploration advances the overarching goal of sustainable development in the oil and gas industries by providing insights into understanding, monitoring, and mitigating H2S corrosion. The findings presented here offer a foundation for developing environmentally conscious strategies and practices to guarantee the long-term viability and flexibility of refinery operations.