Metallurgy and Corrosion Control in Oil and Gas Production

Robert Heidersbach

• Publisher: Wiley
• Year: 2018
• ISBN:
  9781119252375
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Industrial & Technical Chemistry

Details the proper methods to assess, prevent, and reduce corrosion in the oil industry using today's most advanced technologies

This book discusses upstream operations, with an emphasis on production, and pipelines, which are closely tied to upstream operations. It also examines protective coatings, alloy selection, chemical treatments, and cathodic protection—the main means of corrosion control. The strength and hardness levels of metals is also discussed, as this affects the resistance of metals to hydrogen embrittlement, a major concern for high-strength steels and some other alloys. It is intended for use by personnel with limited backgrounds in chemistry, metallurgy, and corrosion and will give them a general understanding of how and why corrosion occurs and the practical approaches to how the effects of corrosion can be mitigated.

Metallurgy and Corrosion Control in Oil and Gas Production, Second Edition updates the original chapters while including a new case studies chapter. Beginning with an introduction to oilfield metallurgy and corrosion control, the book provides in-depth coverage of the field with chapters on: chemistry of corrosion; corrosive environments; materials; forms of corrosion; corrosion control; inspection, monitoring, and testing; and oilfield equipment.

• Covers all aspects of upstream oil and gas production from downhole drilling to pipelines and tanker terminal operations
• Offers an introduction to corrosion for entry-level corrosion control specialists
• Contains detailed photographs to illustrate descriptions in the text

Metallurgy and Corrosion Control in Oil and Gas Production, Second Edition is an excellent book for engineers and related professionals in the oil and gas production industries. It will also be an asset to the entry-level corrosion control professional who may have a theoretical background in metallurgy, chemistry, or a related field, but who needs to understand the practical limitations of large-scale industrial operations associated with oil and gas production.

1
INTRODUCTION TO OILFIELD METALLURGY AND CORROSION CONTROL

The American Petroleum Institute (API) divides the petroleum industry into the following categories:

• Upstream
• Downstream
• Pipelines

Other organizations use terms like production, pipelining, transportation, and refining. This book will discuss upstream operations, with an emphasis on production, and pipelines, which are closely tied to upstream operations. Many “pipelines” could also be termed gathering lines or flowlines, and the technologies involved in materials selection and corrosion control are similar for all three categories of equipment.

Until the 1980s metals used in upstream production operations were primarily carbon steels. Developments of deep hot gas wells in the 1980s led to the use of corrosion‐resistant alloys (CRAs), and this trend continues as the industry becomes involved in deeper and more aggressive environments [1, 2]. Nonetheless, most metal used in oil and gas production is carbon or low‐alloy steel, and nonmetallic materials are used much less than metals.

Increased emphasis on reliability also contributes to the use of newer or more corrosion‐resistant materials. Many oilfields that were designed with anticipated operating lives of 20–30 years are still economically viable after more than 50 years. This life extension of oilfields is the result of increases in the market value of petroleum products and the development of enhanced recovery techniques that make possible the recovery of larger fractions of the hydrocarbons in downhole formations. Unfortunately, this tendency to prolong the life of oilfields creates corrosion and reliability problems in older fields when reductions in production and return on investment cause management to become reluctant to spend additional resources on maintenance and inspection.

These trends have all led to an industry that tends to design for much longer production lives and tries to use more reliable designs and materials. The previous tendency to rely on maintenance is being replaced by the trend to design more robust and reliable systems instead of relying on inspection and maintenance. The reduction in available trained labor for maintenance also drives this trend.

COSTS

A US government report estimated that the cost of corrosion in upstream operations and pipelines was $1372 billion per year, with the largest expenses associated with pipelines followed by downhole tubing and increased capital expenditures (primarily the use of CRAs). The most important opportunity for savings is the prevention of failures that lead to lost production. The same report suggested that the lack of corrosion problems in existing systems does not justify reduced maintenance budgets, which is a recognition that, as oilfields age, they become more corrosive at times when reduced returns on investment are occurring [3]. The 2013 environmental cracking problems with offshore pipelines in the Caspian Sea Kashagan oilfield are estimated to have cost billions of dollars for pipeline replacement costs plus lost production [4]. It is estimated that corrosion costs are approximately equal to mechanical breakdowns in maintenance costs.

SAFETY

While proper equipment design, materials selection, and corrosion control can result in monetary savings, a perhaps more important reason for corrosion control is safety. Hydrogen sulfide, H₂S, is a common component of many produced fluids. It is poisonous to humans, and it also causes a variety of environmental cracking problems. The proper selection of H₂S‐resistant materials is a subject of continuing efforts, and new industrial standards related to defining metals and other materials that can safely be used in H₂S‐containing (often called “sour”) environments are being developed and revised due to research and field investigations [2].

Pipelines and other oilfield equipment frequently operate at high fluid pressures. Crude oil pipelines can leak and cause environmental damage, but natural gas pipeline leaks, like the corrosion‐related rupture in Carlsbad, New Mexico, shown in Figure 1.1, can lead to explosions and are sometimes fatal [5]. High‐pressure gas releases can also cause expansive cooling leading to brittle behavior on otherwise ductile pipelines. API standards for line pipe were revised in 2000 to recognize this possibility. Older pipelines, constructed before implementation of these revised standards, are usually made from steel with no controls on low‐temperature brittle behavior and may develop brittle problems if they leak. Gas pipelines are more dangerous than liquid pipelines, because of the stored energy associated with compression of enclosed fluid.

Figure 1.1 Natural gas pipeline rupture near Carlsbad, New Mexico, in 2000.

Source: From Pipeline Accident Report [5].

ENVIRONMENTAL DAMAGE

Environmental concerns are also a reason for corrosion control [6]. Figure 1.2 shows oil leaking from a pipeline that suffered internal corrosion followed by subsequent splitting along a longitudinal weld seam. The damages due to this leak are minimal compared with the environmental damages that would have resulted if the leak had been on a submerged pipeline. Figure 1.3 shows an oil containment boom on a river where a submerged crude oil pipeline was leaking due to external corrosion caused by nonadherent protective coatings that shielded the exposed metal surfaces from protective cathodic protection currents.

Figure 1.2 Aboveground leak from an internally corroded crude oil pipeline.

Figure 1.3 An oil containment boom to minimize the spread of crude oil from an external corrosion leak on a submerged pipeline.

In the 1990s, the entire downtown area of Avila Beach, California, was closed because of leaking underground oil pipelines. The cleanup from these corroded pipelines took years and cost millions of do...

Table of contents

• COVER
• TABLE OF CONTENTS
• PREFACE
• 1 INTRODUCTION TO OILFIELD METALLURGY AND CORROSION CONTROL
• 2 CHEMISTRY OF CORROSION
• 3 CORROSIVE ENVIRONMENTS
• 4 MATERIALS
• 5 FORMS OF CORROSION
• 6 CORROSION CONTROL
• 7 INSPECTION, MONITORING, AND TESTING
• 8 OILFIELD EQUIPMENT
• INDEX
• END USER LICENSE AGREEMENT