scholarly journals Drill Stem Steels for Use in Geothermal Environments

1981 ◽  
Vol 103 (2) ◽  
pp. 159-165
Author(s):  
R. Salzbrenner
Keyword(s):  
Weight Percent ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Drill Stem ◽  
Geothermal Fluids ◽  
Duplex Steel ◽  
Drilling Operations ◽  
Geothermal Environments ◽  
Geothermal Drilling ◽  
Carbon System

Steels which are used in drill stem for conventional drilling have been selected primarily to satisfy certain static strength requirements and cost considerations. As the environments in which drilling is performed become more severe (e.g., in geothermal fluids) additional considerations must be given to the design of alloys which are resistant to general corrosion, stress corrosion, and corrosion fatigue. General design considerations for steel alloys which should provide an enhanced resistance to geothermal drilling operations are presented. These considerations include discussion of the chemistry and metallurgical substructure, and how their variation affects the mechanical and corrosion properties of steel used for drill stem applications. A duplex ferritic-martensitic steel has an advantageous combination of compositional and microstructural features which should lead to improved chemical resistance (particularly to hydrogen sulfide) as well as provide a good combination of strength and toughness properties. This duplex steel is based on the iron-2.0 weight percent silicon-0.1 weight percent carbon system, and offers the potential of enhanced performance in geothermal drilling as well as low alloy cost.

scholarly journals Effect of Structural Modification on Corrosion Behavior of Hypo Eutectic Al-Si Alloy

2018 ◽  
Vol 778 ◽  
pp. 16-21
Author(s):  
Muhammad Mansoor ◽  
Muhammad Kamran Yaseen ◽  
Shaheed Khan
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Earth Metal ◽  
Alloy System ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Unmodified Alloy ◽  
Cast Alloys

Al-Si eutectic cast alloys are widely used in aeronautical and automobile industries where significantly high strength, toughness and wear resistance are required. This class of cast alloys exhibit relatively low corrosion resistance in brine environments. The mechanical properties of the alloy system mainly depend upon the shape of Si rich eutectic phase, which mainly has acicular geometry. In present research, the effect of modified microstructure of 12 wt. % Si-Al alloy on corrosion behavior was studied. The needle like Si rich eutectic phase was modified to disperse spherical structure using rare earth metal halides. The corrosion rate and pitting behavior of modified and unmodified alloy were evaluated in 3.5% NaCl solution by general corrosion for calculated time. It was observed that the corrosion rate and pitting tendency of modified alloy had been appreciably reduced as compare to unmodified alloy. The improvement of corrosion properties were the attributes of changed morphology and distribution of Si rich eutectic phase.

scholarly journals How Can Temperature Logs Help Identify Permeable Fractures and Define a Conceptual Model of Fluid Circulation? An Example from Deep Geothermal Wells in the Upper Rhine Graben

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jeanne Vidal ◽  
Régis Hehn ◽  
Carole Glaas ◽  
Albert Genter
Keyword(s):  
Upper Rhine Graben ◽  
Fluid Circulation ◽  
Geothermal Heat ◽  
Geothermal Fluids ◽  
Rhine Graben ◽  
Sensitive Tool ◽  
Geothermal Wells ◽  
Different Temperatures ◽  
Drilling Operations ◽  
Upper Rhine

Identifying fluid circulation in fracture zones (FZs) is a key challenge in the extraction of deep geothermal heat from natural reservoirs in the Upper Rhine Graben. This study focuses on permeable FZs present within the granitic basement penetrated by deep geothermal well GPK-1 at Soultz and GRT-1 and GRT-2 at Rittershoffen (France). The various temperature (T) log datasets acquired from these wells during production and at equilibrium, with the associated flow logs, allow for the unique opportunity to interpret fluid circulation at the borehole scale. All permeable FZs identified by permeability indicators measured during drilling operations and from image logs spatially coincide with positive or negative T anomalies observed in the T logs during production and/or at equilibrium. However, within the FZs, partially open fractures act as narrower paths for circulation at different temperatures. These temperatures can even be estimated with confidence if the associated flow log is available. The polarity of the T anomalies correlates with the state of equilibrium of the well and thus can change over the well history. During production, the temperature of the water inflow through the fractures can be estimated relative to the mixture of water circulating below the fractures. At thermal equilibrium, the water temperature is estimated with respect to the temperature of the surrounding rock formation. Because temperature fluxes and geothermal fluids are intimately linked, T logs are a useful, reliable, and very sensitive tool to localize the inflow of geothermal water through FZs.

scholarly journals Mechanical and Corrosion Properties of a Duplex Steel Welded using Micro-Arc or Laser

2015 ◽  
Vol 18 (4) ◽  
pp. 723-731 ◽  
Author(s):  
Milton Sergio Fernandes de Lima ◽  
Sheila Medeiros de Carvalho ◽  
Viviane Teleginski ◽  
Moisés Pariona
Keyword(s):  
Corrosion Properties ◽  
Duplex Steel ◽  
Mechanical And Corrosion Properties

General Corrosion Properties of Modified PNC1520 Austenitic Stainless Steel in Supercritical Water as a Fuel Cladding Candidate Material for Supercritical Water Reactor

2010 ◽  
Vol 73 ◽  
pp. 72-77
Author(s):  
Yoshihisa Nakazono ◽  
Takeo Iwai ◽  
Hiroaki Abe
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Supercritical Water ◽  
Reactor Core ◽  
General Corrosion ◽  
Fuel Cladding ◽  
Corrosion Properties ◽  
Energy Agency ◽  
Water Reactor ◽  
Supercritical Water Reactor

The Super-Critical Water-cooled Reactor (SCWR) has been designed and investigated because of its high thermal efficiency and plant simplification. As the operating temperature of supercritical water reactor will be between 280°C and 620°C with a pressure of 25MPa, the selection of materials is difficult and important. The PNC1520 austenitic stainless steel developed by Japan Atomic Energy Agency (JAEA) as a nuclear fuel cladding material for a Na-cooled fast breeder reactor. The corrosion data of PNC1520 in supercritical water (SCW) is required but does not exist. The purpose of the present study is to research the corrosion properties for PNC1520 austenitic stainless steel in supercritical water. The supercritical water corrosion test was performed for the standard PNC1520 (1520S), the Ti-additional type of PNC1520 (1520Ti) and the Zr-additional type of PNC1520 (1520Zr) by using a supercritical water autoclave. In view of general corrosion, 1520Zr may have larger possibility than 1520S and 1520Ti to adopt a supercritical water reactor core fuel cladding.

scholarly journals New approach to development and manufacturing technologies of duplex steel

2019 ◽  
Vol 121 ◽  
pp. 04010
Author(s):  
Victor Orlov ◽  
Leonid Levkov ◽  
Vladimir Dub ◽  
Alan Balikoev ◽  
Dmitry Shurygin
Keyword(s):  
Oil And Gas ◽  
Sea Water ◽  
Average Distance ◽  
Production Equipment ◽  
Gas Production ◽  
Effective Control ◽  
Two Phase ◽  
Corrosion Properties ◽  
Duplex Steel ◽  
Duplex Steels

We conducted a brief review of current production and application of duplex and super duplex steels for manufacture of equipment exposed to the hazard of sulphide stress-corrosion cracking, sea water and other corrosive environment. The super duplex steel with enhanced corrosion-mechanical characteristics in comparison with the known steels of austenitic-ferritic class was developed. Based on the concepts of formation of a special structure of two-phase austenitic-ferritic steels in the process of crystallization, the possibilities of compositional, technological, thermal and special impact techniques are considered and advanced ways of controlling physical, chemical, structural homogeneity and properties of super duplex steels are developed. Electroslag remelting with the application of low-frequency alternating current provides effective control over the length of the two-phase area, the size of the primary dendrites of the austenitic and ferritic phases, the average distance between their axes, the parameters of the crystallizing cell, the development of liquation phenomena and the size of the growing non-metallic phases. Within framework of the proposed approach, the thermodynamic and kinetic conditions for the formation and growth of hardening phases are assessed, a new composition and a complex technology for the manufacture of corrosion-resistant super duplex steels for gas and oil production equipment has been developed. Thermodynamically stable, having sizes of 30-300 nm, niobium nitrides and carbonitrides are located inside the grains of the ferritic phase. At the same time, the sigma phase and chromium carbide precipitates at the intergrain boundaries are not observed. The results of the determination of mechanical and corrosion properties in accordance with the NACE TM 0177 standard (method A), tests of corrosion witness-samples in field conditions demonstrate the advantages and prospects of using new super duplex steel for the manufacture of oil and gas production equipment operating in an environment with high H2S content and CO2 under significant mechanical loads, without the risk of brittle fracture.

scholarly journals Influence of intraoral application of antiseptics and fluorides during orthodontic treatment on corrosion and mechanical characteristics of nickel-titanium alloy in orthodontic appliances

2021 ◽  
Author(s):  
Tihana Zibar Belasic ◽  
Biljana Pejova ◽  
Helena Otmacic Curkovic ◽  
Ervin Kamenar ◽  
Bojana Cetenovic ◽  
...  
Keyword(s):  
Niti Alloy ◽  
Surface Characteristics ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
Oral Exposure ◽  
Orthodontic Appliances ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Dental Biofilm

ABSTRACT Objectives To explore whether the commercial agents recommended for controlling dental biofilm formation had a significant effect in vivo on mechanical and corrosion properties of nickel-titanium (NiTi) alloy. Materials and Methods NiTi archwires (dimensions 0.508 × 0.508 mm) were collected from 36 orthodontic patients aged 13–42 years after a 3-month intraoral exposure. Three experimental groups were formed: (1) subjects conducting regular oral hygiene, (2) subjects who used fluorides for intensive prophylaxis for the first month, and (3) subjects who used chlorhexidine in the same manner. Corrosion behavior, surface characteristics, stiffness, hardness, and friction were analyzed. Results Exposure to intraoral conditions significantly reduced the stiffness and hardness of the NiTi alloy (P ≤ .015). Fluoride tended to reduce stiffness and hardness more than did saliva or antiseptic, but not significantly. Roughness and friction were not significantly influenced by oral exposure. Intraoral aging predominantly produced general corrosion independent of the adjuvant prophylactic agent, although localized corrosion may also have occurred. Conclusions Fluorides and the antiseptic chlorhexidine do not increase corrosion more than saliva itself, nor do they further modify the mechanical properties of the NiTi alloy.

scholarly journals Maintenance Impact on Geothermal Drilling Operations. A Case Study Approach

2021 ◽  
Vol 11 (02) ◽  
pp. 183-201
Author(s):  
Stanley M. Mburu ◽  
James M. Wakiru ◽  
Peter N. Muchiri ◽  
Liliane Pintelon
Keyword(s):  
Case Study Approach ◽  
Study Approach ◽  
Drilling Operations ◽  
Geothermal Drilling

Microstructural and Corrosion Studies of the Ti-2 Wt % Ni Alloy

1974 ◽  
Vol 32 ◽  
pp. 516-517
Author(s):  
Anna C. Fraker
Keyword(s):  
Random Distribution ◽  
Pure Titanium ◽  
Weight Percent ◽  
Heat Treatments ◽  
Minimum Size ◽  
Corrosion Properties ◽  
Percent Nickel ◽  
Transmission Electron ◽  
Corrosion Studies ◽  
Ni Alloy

The purpose of this paper is to show, using light microscopy and transmission electron microscopy (TEM), the vast differences in precipitate distribution in the Ti-2Ni alloy which result from varying heat treatments in the 500° to 1000°C temperature range. This alloy is of interest because it has a high resistance to crevice corrosion. This resistance is attributed to the presence of the two weight percent nickel and is at a maximum when the Ti2Ni precipitate phase has a minimum size and random distribution. (α-Titanium has a solubility for nickel of <0.2 wt.% so the two percent nickel is in the Ti2Ni phase.) Heat treatments which produce changes in the size and distribution of the Ti2Ni precipitates will affect the corrosion properties of the alloy on a local scale. Sedriks, et al. showed the Ti2Ni phase to have higher anodic polarization currents than pure titanium.

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