Fatigue Behavior of API X-80 Steels

2012 ◽  
Author(s):  
Jaeki Kwon ◽  
Daeho Jeong ◽  
Inkyun Choi ◽  
Youngju Kim ◽  
Namsub Woo ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Sea Water ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Good Combination ◽  
Oil Well ◽  
Testing Conditions ◽  
Tidal Motion ◽  
R Ratio ◽  
Corrosive Environments

API X-80 steel is extensively used as a piping material in oil and gas industries with good combination of strength, toughness and resistance to H2S damage. Drill riser, for example, is a conduit providing a temporary extension of a subsea oil well to surface drilling facility and is in large part made of welded X-80 steel pipe. The riser system is subject to fatigue loading from wave and tidal motion, vortex induced vibration (VIV) and operating loads at low temperatures in corrosive environments. The reliability of drill riser system is extremely important and therefore the effects of environmental factors, including temperature and seawater, on fatigue crack propagation (FCP) behavior of X-80 steels, both BM (base metal) and WM (weld metal), need to be well understood. In this study, S-N fatigue and FCP tests were conducted on X-80 steel, including BM and WM, in air at 25 and −50°C and an R ratio of 0.1. The FCP tests were also performed on X-80 steel BM in artificial sea water at both cathodically and anodically controlled voltages. The fatigue behavior of X-80 steel at various testing conditions are discussed based on detailed optical micrographic and SEM fractographic observations.

On the in vitro Fatigue Behavior of Human Dentin: Effect of Mean Stress

2004 ◽  
Vol 83 (3) ◽  
pp. 211-215 ◽  
Author(s):  
R.K. Nalla ◽  
J.H. Kinney ◽  
S.J. Marshall ◽  
R.O. Ritchie
Keyword(s):  
Fatigue Failure ◽  
Fatigue Behavior ◽  
Load Ratio ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
R Ratio ◽  
Wide Range ◽  
Human Dentin ◽  
Mean Stresses

Human dentin is susceptible to failure under repetitive cyclic-fatigue loading. This investigation seeks to address the paucity of data that reliably quantify this phenomenon. Specifically, the effect of alternating vs. mean stresses, characterized by the stress- or load-ratio R (ratio of minimum-to-maximum stress), was investigated for three R values (−1, 0.1, and 0.5). Dentin was observed to be prone to fatigue failure under cyclic stresses, with susceptibility varying, depending upon the stress level. The “stress-life” ( S/N) data obtained are discussed in the context of constant-life diagrams for fatigue failure. The results provide the first fatigue data for human dentin under tension-compression loading and serve to map out safe and unsafe regimes for failure over a wide range of in vitro fatigue lives (< 103 to > 106 cycles).

Influence of Texture and Environmental Effects on Fatigue Behavior of Ti-6Al-4V Alloy

2017 ◽  
Vol 754 ◽  
pp. 39-42 ◽  
Author(s):  
Sergio Baragetti ◽  
Nedunchezhian Srinivasan ◽  
Ravi Kumar
Keyword(s):  
Fatigue Strength ◽  
Grain Boundaries ◽  
Environmental Effects ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Aged Condition ◽  
Air Samples ◽  
Secondary Cracks ◽  
Corrosive Environments

Ti-6Al-4V alloy in solutionized and aged condition was subjected to axial fatigue testing in air and corrosive environments respectively. Severity of the methanol damage as evidenced through fractographic studies, corroborates loss in fatigue strength of samples tested in methanol environment in contrast to samples tested in air. Samples subjected to fatigue loading in NaCl environment revealed extensive secondary cracks along alpha grain boundaries.

Influence of Fatigue Loading on the Engineering Critical Assessment of Steel Catenary Risers in Sour Deepwater Oil and Gas Developments

2009 ◽  
Vol 413-414 ◽  
pp. 313-325 ◽  
Author(s):  
Colum M. Holtam ◽  
David P. Baxter ◽  
Rachel C. Thomson ◽  
Ian A. Ashcroft
Keyword(s):  
Best Practice ◽  
Oil And Gas ◽  
Internal Surface ◽  
Fatigue Loading ◽  
Defect Tolerance ◽  
Tidal Motion ◽  
Failure Assessment ◽  
Steel Catenary Risers ◽  
Input Variables ◽  
Practice Methods

Steel catenary risers (SCR) are used in deepwater oil and gas developments to transfer produced fluids from the seabed to surface facilities. SCRs can be subject to fatigue loading from a variety of sources including wave and tidal motion, vortex induced vibration (VIV) and operating loads. When the produced fluids are sour (ie contain water and H2S) higher fatigue crack growth rates (FCGR) are expected, and this can have a significant effect on defect tolerance. The aim of this paper is to provide guidance on the current best practice methods for performing engineering critical assessments (ECA) on internal surface breaking defects in SCRs operating in a sour environment and subject to VIV fatigue loads. Example ECA calculations are presented for circumferential girth weld flaws, based on the failure assessment diagram (FAD) approach within the framework of BS 7910 [1]. The influence of certain key input variables is demonstrated, including the FCGR, determined from recent sour test data generated as part of this research.

Development of a Double Joint Welding Procedure Specification for Fatigue Applications

2016 ◽  
Author(s):  
Israel Marines-Garcia ◽  
Emma Erezuma ◽  
Noe Mota-Solis ◽  
Philippe P. Darcis ◽  
Hector M. Quintanilla
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Gas Recovery ◽  
X65 Steel ◽  
Steel Catenary Risers ◽  
Service Environments ◽  
Firing Line ◽  
Welding Procedure

One of the major concerns in terms of Structural Integrity for Steel Catenary Risers (SCR) or Fatigue Sensitive Flowlines (FSFL) consists on their strength to withstand dynamic loading along their service life. SCR and FSFL systems always experience more considerable fatigue loading due to floating structures adopted for deep and ultra-deep water oil and gas recovery, as well as for free spanning due to seabed geography and marine currents. In this context, a Double Joint (DJ) Welding Procedure Specification (WPS) has been developed to comply with stringent fatigue requirements, as well as to assess their actual fatigue behavior. The benefits of having DJ are: improving the installation time (S-lay, J-lay or reel-lay) having half of the welding joint performed out of the firing line and reducing the need of Field Joint Coating by two, which results on decreasing project’s cost. This DJ development is focused on a more productive WPS applicable for sour service environments and fatigue endurance requirements considering a Narrow Groove (NG) with J-Bevel design, STT® root pass, SAW for fill and cap passes in 1G welding position. The obtained WPS results are presented on an X65 Steel pipe grade, 273.1 mm OD and 25.4 mm WT.

ASSESSMENT OF OIL WELL PRODUCTIVITY IN LOW-PERMEABILITY RESERVOIRS IN THE FIELDS OF EASTERN SIBERIA

2017 ◽  
pp. 30-36
Author(s):  
R. V. Urvantsev ◽  
S. E. Cheban
Keyword(s):  
Oil Recovery ◽  
Large Scale ◽  
Oil And Gas ◽  
Oil Extraction ◽  
Low Permeability ◽  
Oil Well ◽  
Eastern Siberia ◽  
Development Costs ◽  
Traditional Fields ◽  
Low Permeability Reservoirs

The 21st century witnessed the development of the oil extraction industry in Russia due to the intensifica- tion of its production at the existing traditional fields of Western Siberia, the Volga region and other oil-extracting regions, and due discovering new oil and gas provinces. At that time the path to the development of fields in Eastern Siberia was already paved. The large-scale discoveries of a number of fields made here in the 70s-80s of the 20th century are only being developed now. The process of development itself is rather slow in view of a number of reasons. Create a problem of high cost value of oil extraction in the region. One of the major tasks is obtaining the maximum oil recovery factor while reducing the development costs. The carbonate layer lying within the Katangsky suite is low-permeability, and its inventories are categorised as hard to recover. Now, the object is at a stage of trial development,which foregrounds researches on selecting the effective methods of oil extraction.

Simulation of Two Phase Flow Dynamics in Flexible Riser Exit Geometries for Oil and Gas Applications

2018 ◽  
Vol 39 ◽  
pp. 1-13
Author(s):  
Ikpe E. Aniekan ◽  
Owunna Ikechukwu ◽  
Satope Paul
Keyword(s):  
Oil And Gas ◽  
Two Phase Flow ◽  
Flow Analysis ◽  
Computational Cost ◽  
Maximum Velocity ◽  
Oil Well ◽  
Phase Flow ◽  
Two Phase ◽  
The Third ◽  
Riser Pipe

Four different riser pipe exit configurations were modelled and the flow across them analysed using STAR CCM+ CFD codes. The analysis was limited to exit configurations because of the length to diameter ratio of riser pipes and the limitations of CFD codes available. Two phase flow analysis of the flow through each of the exit configurations was attempted. The various parameters required for detailed study of the flow were computed. The maximum velocity within the pipe in a two phase flow were determined to 3.42 m/s for an 8 (eight) inch riser pipe. After thorough analysis of the two phase flow regime in each of the individual exit configurations, the third and the fourth exit configurations were seen to have flow properties that ensures easy flow within the production system as well as ensure lower computational cost. Convergence (Iterations), total pressure, static pressure, velocity and pressure drop were used as criteria matrix for selecting ideal riser exit geometry, and the third exit geometry was adjudged the ideal exit geometry of all the geometries. The flow in the third riser exit configuration was modelled as a two phase flow. From the results of the two phase flow analysis, it was concluded that the third riser configuration be used in industrial applications to ensure free flow of crude oil and gas from the oil well during oil production.

scholarly journals Corrosion Inhibition of Tubing Steel during Acidization of Oil and Gas Wells

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
M. Yadav ◽  
Sumit Kumar ◽  
P. N. Yadav
Keyword(s):  
Corrosion Inhibition ◽  
Oil And Gas ◽  
Ac Impedance ◽  
Charge Transfer Resistance ◽  
Gas Production ◽  
Oil Well ◽  
Transfer Resistance ◽  
Oil And Gas Production ◽  
N80 Steel ◽  
High Degree

Acidization is an oil reservoir stimulation technique for increasing oil well productivity. Hydrochloric acid is used in oil and gas production to stimulate the formation. The acid treatment occurs through N80 steel tubes. The process requires a high degree of corrosion inhibition of tubing material (N80 steel). In the present investigation effect of synthesized amino acid compounds, namely, acetamidoleucine (AAL) and benzamidoleucine (BAL) as corrosion inhibitors for N80 steel in 15% HCl solution was studied by polarization, AC impedance (EIS), and weight loss measurements. It was found that both the inhibitors were effective inhibitors and their inhibition efficiency was significantly increased with increasing concentration of inhibitors. Polarization curves revealed that the studied inhibitors represent mixed type inhibitors. AC impedance studies revealed that charge transfer resistance increases and double layer capacitance decreases in presence of inhibitors. Adsorption of inhibitors at the surface of N80 steel was found to obey Langmuir isotherm.

The Effect of Opal-Containing Rocks on the Properties of Lightweight Oil-Well Cement

2021 ◽  
Vol 325 ◽  
pp. 47-52
Author(s):  
Fedor L. Kapustin ◽  
N.N. Bashkatov ◽  
Rudolf Hela
Keyword(s):  
Flexural Strength ◽  
Oil And Gas ◽  
Gas Production ◽  
Cement Stone ◽  
Oil Well ◽  
Cement Slurry ◽  
Water Separation ◽  
Oil And Gas Production ◽  
Geological Conditions ◽  
Cement Grinding

When constructing deep wells for oil and gas production in difficult geological conditions, special lightweight oil-well cements are used. To reduce the density and water separation of the cement slurry as well as to increase the strength, corrosion resistance of cement stone and the quality of well cementing, opal-containing rocks, fly ash, microsphere and other lightening additives are introduced into the cement composition. The influence of sedimentary rocks, such as opoka, tripoli, and diatomite containing from 43 to 81% amorphous silica on the grindability, rheological and physical-mechanical properties of lightweight oil-well Portland cement has been studied. The twelve cement compositions with different content of additives (from 30 to 45%) that meet the requirements of the standard for density, spreadability, water separation, thickening time and flexural strength were selected. The introduction of 45% diatomite or tripoli significantly reduces the duration of cement grinding, provides the cement slurry with water-cement ratio of 0.9 with better density and flexural strength, respectively, 1480 kg/m3 and 1.1–1.5 MPa.

Combined effects of sulfate attack under drying–wetting cycles and loading on the fatigue behavior of concrete

2021 ◽  
pp. 136943322110427
Author(s):  
Ping Zhang ◽  
Song Ren ◽  
Yunfeng Zhao ◽  
Le Wang ◽  
Nengzeng Long ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Sodium Sulfate ◽  
Fatigue Behavior ◽  
Residual Deformation ◽  
Fatigue Loading ◽  
Damage Variable ◽  
Fatigue Properties ◽  
Sulfate Concentration ◽  
Cycle Number ◽  
Major Cycle

Concrete structures often undergo both fatigue loading and environmental impacts during their useful lifetime. This study aims to explore the fatigue properties of concrete subjected to sulfate attacks under drying–wetting cycles and loading. The coupled influences of major cycle number and sodium sulfate solution on the residual deformation, elastic modulus, and damage variable were investigated by uniaxial cyclic loading tests. Moreover, the phase composition of concrete samples was examined by X-ray diffraction. Results indicate that the concrete residual deformation and damage variable could be classified into initial and stable stages, while the elastic modulus fluctuated within a certain range. The fatigue strength of concrete was found to increase with an increase in the major cycle number and sodium sulfate concentration in the early stages, whereas the fatigue performance of concrete decreased as the major cycle number and sodium sulfate concentration increased in the later stage. The degree of influence of major cycle number and sodium sulfate concentration on the fatigue properties of concrete differed in each stage. These findings can contribute to understand the variation pattern of concrete properties in complicated environments and provide an important reference for associated construction projects.

scholarly journals Potential Use of Water Associated with Conventional Oil Production and Sea Water as Base Fluids for Hydraulic Fracturing Operations: Effect of Water Chemistry on Crosslinking and Breaking Behaviors of Guar Gum-Based Fracturing Fluid Formulations

2016 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Dayanand Saini ◽  
Timea Mezei
Keyword(s):  
Los Angeles ◽  
Hydraulic Fracturing ◽  
Water Chemistry ◽  
Fresh Water ◽  
Oil And Gas ◽  
Guar Gum ◽  
Sea Water ◽  
Oil Production ◽  
Fracturing Fluid ◽  
Conventional Oil

 Even though water consumption per hydraulic fracturing (or fracturing) job is relatively low; nearly all of the fresh water used for fracturing in California is in the regions of high water stress such as San Jouquin and Los Angeles Basins. However, water availability should not be a concern as huge volumes of water are being produced along with oil and gas from conventional formations (i.e. associated water) in the Kern County of California, a region where most of the fracturing activities take place. This associated water can potentially be used for preparing fracturing fluids in stimulating the unconventional formations. The present study reports on the relevant investigation done in this area of interest.The results suggest that associated water chemistry has limited effect on the viscosity of cross-linked formulations. However, guar gum concentration was found to affect the breaking behaviors of cross-linked fracturing fluid formulations. The new type of commercially available biodegradable breaker was found to be effective in breaking the tested cross-linked formulations at elevated temperature which was as high as 85°C (185°F). Both crosslinking and breaking behaviors of fracturing fluid formulations evaluated in this study were found comparable to the behaviors of commonly used cross-linked formulation (guar gum + 2% potassium chloride). These results suggest that both the associated water (i.e. water resulting from regional conventional oil production activites) and sea water (offshore oil fields) could serve as alternative sources of base fluid for use in fracturing jobs without putting significant burden on precious regional fresh water resources.

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