Handbook of Materials Failure Analysis with Case Studies from the Oil and Gas Industry (eBook)

Mahmood Aliofkhazraei, Abdel Salam Hamdy Makhlouf (Herausgeber)

eBook Download: PDF | EPUB

2015 | 1. Auflage
448 Seiten
Elsevier Science (Verlag)
978-0-08-100126-4 (ISBN)

Infos

Handbook of Materials Failure Analysis: With Case Studies from the Oil and Gas Industry provides an updated understanding on why materials fail in specific situations, a vital element in developing and engineering new alternatives. This handbook covers analysis of materials failure in the oil and gas industry, where a single failed pipe can result in devastating consequences for people, wildlife, the environment, and the economy of a region. The book combines introductory sections on failure analysis with numerous real world case studies of pipelines and other types of materials failure in the oil and gas industry, including joint failure, leakage in crude oil storage tanks, failure of glass fibre reinforced epoxy pipes, and failure of stainless steel components in offshore platforms, amongst others. - Introduces readers to modern analytical techniques in materials failure analysis - Combines foundational knowledge with current research on the latest developments and innovations in the field - Includes numerous compelling case studies of materials failure in oil and gas pipelines and drilling platforms

Textauszug

Chapter 2

Modern analytical techniques in failure analysis of aerospace, chemical, and oil and gas industries

Seifollah Nasrazadani*; Shokrollah Hassani†    * Engineering Technology Department, University of North Texas, Denton, TX, USA
† BP America Inc., Houston, TX, USA

Abstract

Analytical techniques applicable to failure analysis in different industrial sectors have evolved in past few decades and enhancement of such techniques has been taking place and even intensified in recent years. New analytical procedures and data analysis based on existing techniques and instrumentation are being developed constantly. This chapter reviews the most recent developments in the field of analytical techniques used in failure analysis of aerospace, chemical, and oil and gas industries. The particular focus of this chapter will be on chemical analysis, phase identification, microscopy, and residual stress analysis. In particular, emphasis will be placed on recent advancements in microstructural analysis using tools such as EBSD and focused ion beam, phase analysis based on vibrational spectroscopy, and X-ray diffraction application in residual stress measurements. Basic principle, instrumentation, data interpretation, and precautions for each of the techniques will be discussed. The aim of this chapter will be to provide a solid background on a given technique helping both failure analysis practitioners as well as engineers in different technical fields who will be searching for a suitable method for their problem on hand. Following is a tentative list of techniques to be covered in this chapter categorized based on the type of information they offer.

Keywords

SEM

EDS

FIB

XRF

XRD

FTIR

XPS

Radiography

Neutron radiography

X-ray radiography

Chapter Outline

1 Microscopy Techniques   39

1.1 Optical Microscopy   39

1.2 Scanning Electron Microscopy   40

1.3 Focused Ion Beam   41

2 Chemical and Radiographic Analysis   42

2.1 Energy Dispersive Spectroscopy   42

2.2 X-Ray Fluorescence   44

2.3 X-Ray Diffraction   45

2.4 Fourier Transform Infrared Spectrophotometry   46

2.5 X-Ray Photoelectron Spectroscopy   47

2.6 Radiography   49

2.7 Neutron Radiography   50

2.8 X-Ray Radiography   51

2.9 Gamma-Ray Radiography   52

2.10 Fluoroscopic Radiography   53

3 Conclusion and Future Outlook   53

References   53

1 Microscopy Techniques

1.1 Optical Microscopy

Human curiosity about the shapes and appearance of objects at both macro and micro scales has helped us develop microscopes with higher resolving powers. Human eyes with resolution power of 0.1 mm are not sufficient to observe features smaller than 0.1 mm. Therefore, microscopes with higher resolution are needed to examine materials' features at micro, nano, or angstrom size. By definition, optical resolution is defined as the shortest distance between two points that can be differentiated. Optical microscopes can resolve features approximately 0.2 μm apart. The resolving power of optical microscopes represents three orders of magnitude improvement over that of human eyes. Applications of optical microscopes in the oil and gas industry includes but not limited to geoscience studies, mineral identification, microfossils and biostratification, geochronology as well as porosity analysis. Among the mentioned applications, porosity analysis appears to be more popular due to the fact that the presence of interconnected pores affects permeability of oil and gas in sandstones and this facilitates oil and gas extraction from a reservoir.

1.2 Scanning Electron Microscopy

Scanning electron microscopy (SEM) is the most popular technique in the analysis of failed components in the oil and gas industry. The popularity of SEM is due to the fact that failure mode(s) can be easily identified through morphological features obtained from analysis of the fracture surfaces. Specifically one can look for formation of dimples in a fracture surface of a highly ductile alloy such as low carbon steels as well as all nonferrous alloys, such as aluminum and copper, indicating severe plastic deformation prior to failure. High carbon steels hardened through heat treatment processes can undergo brittle fracture when exposed to subzero temperatures or a sudden blow, exhibiting cleavage fracture morphology that is indicative of fast fracture without any demonstration of plastic deformation. Ferrous and nonferrous alloys experiencing fatigue typically exhibit striation marks indicating application of a cyclic load prior to failure. Oftentimes alloys experiencing fatigue failure demonstrate striation marks but absence of striation marks does not eliminate the possibility of fatigue failure. Figure 2.1a–c show examples of ductile failure (a), brittle failure (b), and fatigue failure (c).

Figure 2.1 SEM micrographs showing morphologies of ductile failure (a), brittle failure (b), and fatigue failure (c).

One of the issues in the oil and gas industry is flow-accelerated corrosion (FAC). SEM has been effectively used in identification of the flow regime based on morphology of the damaged steel surfaces. Steel pipes used in the oil and gas industry where highly energetic fluids such as steam passing through elbows (Figure 2.2a) cause severe FAC in carbon steels and even alloy steels showing scalloped formation shown in a single-phase flow regime (Figure 2.2b) whereas two-phase flow regime results in the formation of tiger bands.

Figure 2.2 Elbow section of a small bore pipe used to transfer single-phase steam (a) and corresponding SEM micrograph (b). Basic principle of SEM.

A SEM image is formed in an electron gun through a shower of electrons (~ 100 nA) produced by either thermionic or field emission mechanisms. Primary electrons bombard surface of the sample under investigation to produce secondary electrons through the inelastic collision of primary electrons and valence electrons orbiting the nucleus of the samples' atoms. A set of electromagnetic lenses guide the shower of electrons to raster sample surface where as a scanning coil controls the spot size of the electron shower. A secondary electron detector is used to collect them and be utilized in image formation. Backscattered electrons are also produced through elastic collision between primary electrons and the nucleus of the sample atoms that can be collected using a backscattered electron detector to produce an image with differentiable contrast in regions with concentration of high atomic number as compared to those of low atomic number elements. X-ray signals are also produced and utilized for chemical identification of materials on the surface of atoms. This aspect will be discussed in detail in the following sections.

Samples used in SEM analysis must be vacuum (10− 6 torr) compatible though recent developments in new designs of SEMs (called environmental SEM) capable of operating at pressure of 13 torr that is much closer to atmospheric pressure (760 torr). Exposure of nonconductive samples to an electron shower results in electrical charging of the sample producing a useless image with glaring spots. Deposition of ~ 100 Å gold or carbon coating eliminates the charging issue.

1.3 Focused Ion Beam

Focused ion beam (FIB) technique is analogous to SEM with the exception of using Ga ions in place of electrons (used in SEM) to form an image. FIB has a highly enhanced resolution that allows observation of much finer features such as porosity in core samples cut and drilled in the geological analysis for oil and gas industry used in oil exploration efforts. Application of FIB in core sample analysis reduces oil and gas explorations' risks. Pore analysis can provide quantitative chemical analysis of minerals that contain pores at nanometer scale. Organic matters also contain pores at the nanometer scale that require highly resolved images to be observed. Simultaneous observations on pore size and chemical quantification can be achieved through transmission electron microscopy (TEM). FIB can be used to prepare samples for TEM analysis saving sample preparation time and cost.

Sample preparation to the nanometer thickness has been a challenge in the past but the advent of FIB has reduced time and cost needed for sample preparations for TEM significantly. Figure 2.3 shows a FIB image of a mineral sample...

Produkt-Details

• Erscheint lt. Verlag: 1.9.2015
• Sprache: englisch
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Bergbau
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Wirtschaft
• ISBN-10: 0-08-100126-6 / 0081001266
• ISBN-13: 978-0-08-100126-4 / 9780081001264