Formation of Microgrooving on C110 casing steel after Sulfide Stress Cracking Test

CORROSION ◽  
10.5006/3714 ◽  
2021 ◽  
Author(s):  
Christophe Mendibide ◽  
Claude Duret Thual
Keyword(s):  
Uniaxial Tensile ◽  
Cross Sectional ◽  
Testing Conditions ◽  
Stress Cracking ◽  
Test Conditions ◽  
Test Parameters ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service ◽  
C110 Steel

NACE TM0177 is a commonly employed materials qualification standard specifying how Sulfide Stress Cracking (SSC) tests must be conducted and interpreted to verify the suitability of material application in sour service. This standard specifies through the so-called method A test (a tensile uniaxial environmental cracking test) that a material could be considered acceptable for sour service as long as no failure is evidenced after 720 hours of exposure, and no initiation of environmental cracking is observed on the reduced length of the specimen after macrographic observations. After cross-sectional observations, so-called “micro-grooves” can sometimes be evidenced on the surfaces of non-failed specimens. Such features can hardly be interpreted as SSC crack initiation sites considering their shape and depth. Experience, however, shows that the formation of these microgrooves appears to be dependent on test conditions and type of load. This paper presents the results of investigations on the parameters influencing the micro-groove formation on C110 steel after the method A uniaxial tensile SSC test. Test parameters influencing the groove formation are studied, and the results suggest that grooving is not considered as SSC initiation for the testing conditions used in this work

scholarly journals Comparison of 2507 Duplex and 28 % Cr- Austenitic Stainless Steel Corrosion Behavior for High Pressure and High Temperature (HPHT) in Sour Service Condition with C-ring Experiment

2021 ◽  
Author(s):  
Harris Prabowo ◽  
Badrul Munir ◽  
Yudha Pratesa ◽  
Johny W. Soedarsono
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Corrosion Behavior ◽  
Material Selection ◽  
Stress Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service

The scarcity of oil and gas resources made High Pressure and High Temperature (HPHT) reservoir attractive to be developed. The sour service environment gives an additional factor in material selection for HPHT reservoir. Austenitic 28 Cr and super duplex stainless steel 2507 (SS 2507) are proposed to be a potential materials candidate for such conditions. C-ring tests were performed to investigate their corrosion behavior, specifically sulfide stress cracking (SSC) and sulfide stress cracking susceptibility. The C-ring tests were done under 2.55 % H2S (31.48 psia) and 50 % CO2 (617.25 psia). The testing was done in static environment conditions. Regardless of good SSC resistance for both materials, different pitting resistance is seen in both materials. The pitting resistance did not follow the general Pitting Resistance Equivalent Number (PREN), since SS 2507 super duplex (PREN > 40) has more pitting density than 28 Cr austenitic stainless steel (PREN < 40). SS 2507 super duplex pit shape tends to be larger but shallower than 28 Cr austenitic stainless steel. 28 Cr austenitic stainless steel has a smaller pit density, yet deeper and isolated.

Fit For Service Qualification for Sour Service High Strength Production Casing For High Temperature

2021 ◽  
Author(s):  
Luciana I. L Lima ◽  
Christelle Gomes ◽  
Carine Landier ◽  
Marilia Lima ◽  
Kevin Schleiss ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Yield Strength ◽  
High Strength ◽  
Materials Selection ◽  
Well Production ◽  
Stress Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service ◽  
Minimum Yield

Abstract In recent years the application of high strength carbon steel with 125ksi specified minimum yield strength as a production casing in deepwater and high-pressure reservoirs has increased. Sulfide stress cracking (SSC) can develop when high strength carbon steel is exposed to a sour environment. The H2S partial pressure in these sour reservoirs is above the 0.03 bar limit for this material at room temperature. Materials SSC performance evaluation requires an accurate simulation of field conditions in the laboratory. To evaluate the production casing SSC behavior, some fit for service (FFS) tests were carried out considering the well geothermic temperature profile for the materials selection. This paper presents a fit for service qualification carried out on Casing 125 ksi SMYS (Specified Minimum Yield Strength) materials. Two products with 125ksi SMYS were considered: one that has existed for several years and one developed more recently with a better SSC resistance – above the pH2S limit considered for the standard 125ksi SMYS material. The results obtained in this test program allowed casing 125 ksi SMYS materials selection for temperature above 65°C and environment more severe in terms of pH2S than the domain previously established for this grade. This allowed a new well production design, which saves one casing phase and avoids the necessity to use intermediate liners to prevent collapse.

scholarly journals Improved High-Pressure, High-Temperature (HPHT) Materials Qualification using Dissolved H<sub>2</sub>S Concentration as the Sour Service Scalable Metric

CORROSION ◽  
10.5006/3867 ◽  
2021 ◽  
Author(s):  
BRENT SHERAR ◽  
Peter Ellis II ◽  
Jing Ning
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Phase ◽  
Stress Cracking ◽  
High Pressure High Temperature ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service ◽  
The Relationship ◽  
Severity Parameter

Gas phase H&lt;sub&gt;2&lt;/sub&gt;S partial pressure (P&lt;sub&gt;H2S&lt;/sub&gt;) is associated with sulfide stress cracking (SSC) and is routinely used as the ‘scalable’ parameter to qualify materials for high-pressure, high-temperature (HPHT) wells. Candidate materials for HPHT wells routinely require ANSI/NACE MR0175/ISO 15156 compliance because a few mole ppm of H&lt;sub&gt;2&lt;/sub&gt;S at high pressure may place the well beyond the 0.05 psia (0.3 kPa) sour service threshold. P&lt;sub&gt;H2S&lt;/sub&gt; has been accepted historically as the scalable sour severity parameter. However, as the total pressure increases, the relationship between P&lt;sub&gt;H2S&lt;/sub&gt; and the dissolved H&lt;sub&gt;2&lt;/sub&gt;S concentration becomes non-linear. This limits the robustness of P&lt;sub&gt;H2S&lt;/sub&gt; as the sour severity metric. Thus, ISO 15156-1:2020 now permits the use of H2S fugacity (f&lt;sub&gt;H2S&lt;/sub&gt;), H&lt;sub&gt;2&lt;/sub&gt;S activity (a&lt;sub&gt;H2S&lt;/sub&gt;), and H&lt;sub&gt;2&lt;/sub&gt;S aqueous concentration (C&lt;sub&gt;H2S&lt;/sub&gt;) as alternatives for sour testing. This recent revision is based on evidence that f&lt;sub&gt;H2S&lt;/sub&gt; and C&lt;sub&gt;H2S&lt;/sub&gt; each provide better correlations to SSC at elevated total pressures than P&lt;sub&gt;H2S&lt;/sub&gt;. This paper will address the merits and challenges of using f&lt;sub&gt;H2S&lt;/sub&gt; or C&lt;sub&gt;H2S&lt;/sub&gt; to define sour severity: We argue that C&lt;sub&gt;H2S&lt;/sub&gt; is a practical, experimentally verifiable approach, which can be used to validate ionic-equation of state (EOS) frameworks used to characterize mildly sour HPHT environments.

Effect of Buffer System on the Sulfide Stress Cracking Susceptibility of Low-Alloy Steel

CORROSION ◽  
10.5006/2626 ◽  
2018 ◽  
Vol 74 (7) ◽  
pp. 788-800
Author(s):  
Kenji Kobayashi ◽  
Tomohiko Omura ◽  
Hisashi Amaya
Keyword(s):  
Partial Pressure ◽  
Buffer System ◽  
Low Alloy Steel ◽  
High Co2 ◽  
Co2 Partial Pressure ◽  
Stress Cracking ◽  
Test Conditions ◽  
Sulfide Stress ◽  
Ratio Condition ◽  
Sulfide Stress Cracking

The effects of a buffer system in test solution and CO2 partial pressure on sulfide stress cracking (SSC) susceptibility of low-alloy steel were investigated under pH 4.0 at 0.03 MPa H2S partial pressure. A double cantilever beam test was used to quantitatively evaluate SSC susceptibility. The corrosion rates and absorbed diffusible hydrogen concentration were also evaluated. Acetic acid/sodium acetate (acetate buffered solution) and carbonic acid/bicarbonate (bicarbonate buffered solution) buffered solutions were used as buffer systems in this study. From the results, in atmospheric pressure tests, KISSC values in bicarbonate buffered solutions were equivalent to or lower than those in acetate buffered solutions. In high CO2 partial pressure conditions, KISSC values in bicarbonate buffered solutions were much higher than those in acetate buffered solutions. At a high CO2 partial pressure and H2S partial pressure (pCO2/pH2S) ratio condition, hydrogen entry is considered to be greatly prevented by corrosion products probably containing amorphous iron carbonate. Presence of the corrosion product with high protectiveness produced in the high pCO2/pH2S ratio condition suggests the possibility that conventional test conditions using acetate buffered solutions are conservative or are equivalent test conditions for actual field conditions.

Full Ring Evaluation of X70 Grade UOE Line Pipes for Sour Service

2012 ◽  
Author(s):  
Kenji Kobayashi ◽  
Tomohiko Omura ◽  
Masahiko Hamada ◽  
Hiroyuki Nagayama ◽  
Izuru Minato ◽  
...  
Keyword(s):  
Large Diameter ◽  
High Strength ◽  
Casting Process ◽  
Ring Test ◽  
Past Performance ◽  
Stress Cracking ◽  
Hydrogen Induced Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service

High-strength large-diameter UOE line pipes over X70 grade are difficult to apply to actual fields, including H2S, because of a deterioration of sour resistance and a lack of past performance. However, API X70 grade large-diameter UOE line pipes for sour service have been manufactured stably by optimizing the continuous casting process, controlling the shape of inclusions and decreasing coarse precipitates. A full-ring test can simulate fairly well the actual applied conditions of line pipes and evaluate hydrogen induced cracking (HIC), sulfide stress cracking (SSC) and stress oriented hydrogen induced cracking (SOHIC) of line pipes for sour service simultaneously. It was confirmed that the X70 grade UOE line pipes have a good sour resistance from standard HIC tests, four-point bent beam SSC tests and the full-ring test including a seam weld under severe sour conditions (NACE solution A with 0.1 MPa H2S). In addition, the SSC resistance of a girth welded portion was also investigated by using simulated HAZ.

Effect of Reeling on Sulfide Stress Corrosion Cracking of Welded API5LX65 Line Pipe

2015 ◽  
Author(s):  
Ramgopal Thodla ◽  
Robin Gordon ◽  
Feng Gui
Keyword(s):  
Detrimental Effect ◽  
Aged Condition ◽  
Line Pipe ◽  
Service Environment ◽  
Stress Cracking ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Sour Service ◽  
Hardness Values ◽  
Sulfide Stress Corrosion Cracking

The effect of reeling on sulfide stress cracking (SSC) resistance of welded line pipe was investigated in two different environments, a modified NACE B environment and a fitness for service environment (pH = 5/pH2S = 0.46psia). Micro hardness maps were performed to characterize the welds both in the as fabricated condition as well as in the strained and aged condition. The hardness values in all of the conditions, was less than 250VHN (in compliance with NACE requirements). Triplicate specimens were tested in the as fabricated, strained and aged intrados and extrados in both the environments. SSC resistance in a severely sour environment (pH = 3.5/1psia H2S) was affected by reeling with cracking observed in both the intrados and extrados samples. No cracking was observed in the as-fabricated welds. However, in a moderately sour environment (pH = 5/0.46psia H2S) reeling did not have a detrimental effect on the SSC performance. No evidence of cracking on the as-fabricated, intrados, and extrados welds. In moderate sour service reeling doesn’t appear to have a detrimental effect on the SSC behavior.

Sulfide stress cracking of nickel-containing low-alloy steels

2014 ◽  
Vol 32 (3-4) ◽  
pp. 101-128 ◽  
Author(s):  
Mariano Kappes ◽  
Mariano Iannuzzi ◽  
Raúl B. Rebak ◽  
Ricardo M. Carranza
Keyword(s):  
Mechanical Properties ◽  
Oil And Gas ◽  
Nickel Content ◽  
Low Alloy Steels ◽  
Stress Cracking ◽  
Advantages And Disadvantages ◽  
Sulfide Stress ◽  
Alloy Steels ◽  
Sulfide Stress Cracking ◽  
Sour Service

AbstractLow-alloy steels (LAS) are extensively used in oil and gas (O&G) production due to their good mechanical properties and low cost. Even though nickel improves mechanical properties and hardenability with low penalty on weldability, which is critical for large subsea components, nickel content cannot exceed 1-wt% when used in sour service applications. The ISO 15156-2 standard limits the nickel content in LAS on the assumption that nickel concentrations above 1-wt% negatively impact sulfide stress cracking (SSC) resistance. This restriction excludes a significant number of high-strength and high-toughness alloys, such as Ni-Cr-Mo (e.g., UNS G43200 and G43400), Ni-Mo (e.g., UNS G46200), and Ni-Cr-Mo-V grades, from sour service applications and can be used only if successfully qualified. However, the standard is based on controversial research conducted more than 40 years ago. Since then, researchers have suggested that it is the microstructure that determines SSC resistance, regardless of Ni content. This review summarizes the advantages and disadvantages of nickel-containing LAS in terms of strength, weldability, hardenability, potential weight savings, and cost reduction. Likewise, the state of knowledge on the effect of nickel on hydrogen absorption as well as SSC initiation and propagation kinetics is critically reviewed.

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