Pipelines are a major part of the circulatory and transportation systems of the oil/gas and petrochemical industries. Fluids are produced from the wells and flow through gathering lines or/and flowlines to central points where some degree of processing and separation may take place (in onshore and offshore facilities). The liquids and gases are then placed into pipelines for conveyance to refineries, to chemical plants, or to power producers. The refined products also may pass through pipelines to the ultimate users. At various points wastewater streams (including vast amounts of produced and hydraulic fracture water) are generated, and these very diverse fluids may pass through pipelines before disposal. This frequently means reinjection of a fraction of the fluids into the earth through the injection-well system of a field or into licensed wastewater wells.
The author and technical consultants of this book (see “Acknowledgments”) understand that some of the transportation of well fluids as well as the finished products is accomplished using tanker trucks, barges, trains, and ships of many designs. At the date of the compilation of this book, there was a shortage of pipelines to transport liquids or gas. The cost of rail transport was USD 10–15 more for a barrel of crude oil than by pipeline (Batheja 2014). The book, however concentrates on the piping-conveyed segments of the transportation system.
Although the analogy of a circulatory system breaks down to some extent because all the fluids are not returned to the producing formations, very large volumes of liquids and gases may be reinjected as part of pressure maintenance, enhanced oil recovery, stimulation activities (see Frenier and Ziauddin 2014)., and waste disposal. The “heart” of the processes includes the natural pressure of the producing formations as well as innumerable pumps and gas compressors of all descriptions that maintain the flowing pressure of the systems.
The pipelines are vital and integral parts of the oil/gas systems of the world. Because of recent advances in production of gas and oil from shale formations (Boyer et al. 2011; PI 2012), the future growth in pipeline infrastructure will be significant. INGAA (2011) has predicted the growth for North America through 2035. The values in the following predictions are from this reference.
Natural gas transmission infrastructure
43 Bcf/D of new natural gas transmission capability
400,000 miles of gathering lines (at 16,000 miles/yr)
1,400 miles/yr of new gas transmission mainline
600 miles/yr of new laterals to and from natural-gas-fired power plants, processing facilities, and storage fields
24 Bcf/yr of new working gas capacity in storage
197,000 hp/yr for pipeline compression
Natural gas liquids and oil infrastructure
USD 0.6 billion/year or a total of USD 14.5 billion over the study period for natural gas liquids pipeline expenditures
USD 1.3 billion/year or USD 31.4 billion over the study period of capital expenditures for oil pipelines
Fig. P-1 is a photograph of a pipeline under construction showing some of the welded segments. Fig. P-1a shows sections in the construction ditch with welded and unwelded sections. Fig. P-1b demonstrates the large equipment needed for laying pipeline segments.
Pipelines under construction: (a) individual sections, (b) handling equipment.
An important driver for current construction of additional pipelines is the new light oil as well as the loss of associated natural gas produced in several of the shale oil fields (Bakken in North Dakota, USA, and the Eagle Ford in Texas, USA). Because of the lack of pipelines and gas-treating facilities, as much as 30% of the gas is flared (Fig. P-2) or is used for directly powering hydraulically operated equipment that then vents the gas into the atmosphere (Rahim 2013). A report by Aleklett (2013) includes satellite photos claimed to have been taken by the National Aeronautics and Space Administration of multiple oilfield gas flares in the Bakken and Eagle Ford plays. The illumination from the flares seems to compare in intensity with the illumination of major cities in the regions near the flares. The state of North Dakota as well as a major producer (described in Rahim 2013) are claimed to be committed to dramatically reducing the waste of these hydrocarbon streams by constructing adequate transportation and other ways to use the products in the near future.
This new oil and gas also affects the location of any new pipelines. Speakers (Solomon et al. 2015; Banerjee 2015) at the 2015 Pipeline + Energy Conference and Exposition in Tulsa, Oklahoma, USA, noted that oil quality (light vs. heavy) also plays a role in the geographic direction of new lines as well as the mode of transportation. They noted that the refineries best suited for heavy oil are on the US coast on the Gulf of Mexico and that those designed for light oil are mostly on the US East Coast. Thus, in some cases, rail transportation is currently needed, even if it is costlier than in-place pipelines.
In addition, methane is a potent “greenhouse gas.” USEPA (2013a) noted that the lifetime of methane (CH4) in the atmosphere is much shorter than that of carbon dioxide (CO2), but CH4 is more efficient at trapping radiation than is CO2. The report claims that pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than that of CO2 over a 100-year period. Johnson (2014) has published a short review of the role that oil/gas production plays in contributing to the release of methane to the atmosphere and the actual role it has in global climate change. He cites information that up to 29% of the annual methane loss to the atmosphere comes from oil/gas production and transportation. He claims that because of the trapping-of-heat factor of methane vs. CO2, reducing methane emissions in the short term (i.e., in the next 10 years) should be a global priority.
The needed construction of new gas-handling facilities is in turn driven by the economic value of these resources as well as US Environmental Protection Agency (EPA) regulations (EPA 2012), 40 CFR 98 Subpart W (USEPA 2012), and 40 CFR 60 Subpart OOOO (USEPA 2013b). Details regarding the difficulties of maintaining these current types of oil/gas facilities and new lines are described in Sections 2.2.3 and 2.3.1.
The overall result for some sectors is “Midstream Mania.” Walton (2013) claims that companies that construct, own, or maintain pipelines, tankage, and midstream processing plants are working overtime to meet demand. One section of the article is titled “The Golden Age of Pipelines.” However, the author and consultants for this book note that significant problems have already arisen that must be addressed and thus are the major subject of this book. Note that economic conditions as well as market forces also will affect demand for new pipelines.
Goal and Organization of This Book
This current publication provides an overview of the science and technology of the use of a wide range of pipeline chemicals and mechanical equipment for a general technical audience, with emphasis placed on the basic chemical/physical principles by which the chemicals and devices can enhance or maintain product delivery. Some knowledge of chemistry (equivalent to an introductory college general chemistry course) is assumed. More-advanced concepts are introduced in Chapter 1.
The introductory chapter describes the varied pipeline environments, problems that require chemical or mechanical intervention, and thus the need for the thousands of different chemicals and devices that are in use. This chapter also reviews the important chemical/physical principles that are common to most if not all the enhancement treatments. The applications of interventions described are primarily in the upstream and midstream oil/gas business, but many of the methods can also be used in refineries or product pipelines. This book is limited to internal pipeline flow assurance and reliability issues and does not specifically address external corrosion, internal coatings, or cathodic protection. See Goldschmidt and Streitberger (2003) for references to pipeline coatings and Lazzari and Pedeferri (2006) for cathodic protection information, as well as NACE (2011) for a general review of pipeline corrosion control.
The following is an outline for analysis of potential internal problems in pipelines and facilities:
Is there a problem that requires an intervention?
If there is a problem, how bad will it be?
Can the problem be managed through engineering and/or chemical means?
Evaluate the results of an intervention or control strategy.
Each major section and most subsections will include reviews of current literature as well as summaries of the consensus understandings from the literature cited.
Chapter 1, “Introduction to the Technology of Flow and Integrity Management,” provides an overview of the reasons pipelines require intervention to enhance or maintain product delivery and introduces the various types of chemical and mechanical interventions in use. This chapter also reviews basic chemical and engineering processes that occur in pipeline operations. It also emphasizes the commonality shared among many of the chemical and engineering processes across the pipeline systems as well as the well production processes.
Chapter 2, “From the Well to the Consumer,” describes how the aqueous fluids, hydrocarbon liquids, and gases change from the wellhead, through the gathering lines and surface or subsurface facilities, then through transmission (trunk) pipelines to a consumer. It outlines the chemical/physical forces that ultimately affect the delivery of the products as well as the plans to anticipate and alleviate problems.
Chapter 3, “Corrosion Processes in Pipelines and Facilities,” provides a review of internal corrosion and corrosion mechanisms that affect pipeline/facility operations. Here also are reviewed pertinent texts. In addition, the chapter provides a short introduction to integrity management processes.
Chapter 4, “Chemistry of Product Flow Impairment in Pipelines and Facilities,” describes processes that impair the flow of oil, gas, and water in pipelines and facilities. These include inorganic solids, organic solids, mixed deposits, and emulsions.
Chapter 5, “Mechanical Methods of Enhancement and Assessment of Pipeline Operations,” reviews the many pigs (scrapers), moles, coiled tubing, and jetting equipment used to maintain the lines and to place chemicals in them. The use of hydrostatic testing as well as in-line detection and inspection devices is also reviewed.
Chapter 6, “Chemical and Mechanical Treatments To Enhance/Maintain Pipeline Operations,” shows how chemicals and mechanical devices perform to prevent and inhibit the formation of deposits, corrosion, and emulsions. This chapter also reviews gas dehydration methods, acid gas removal, and flow enhancement chemicals.
Chapter 7, “Cleaning of Pipelines and Facilities,” describes the use of pigging and various chemical cleaning solvents to clear fouled pipelines and units in the facilities. Methods reviewed include chemicals, testing, evaluation, and application of solvents.
Chapter 8, “Pipeline/Facility Maintenance Health, Safety, and Environmental Issues,” reviews issues of health, safety, and the environment related to the maintenance of pipelines and facilities.
Chapters 1 through 8 each concludes with a “Summary and Lessons Learned” section that summarizes the major findings revealed by the review of the technologies discussed and how this knowledge can be applied to pipeline management projects. Chapters 3, 4, 5, 6, and 7 also have a section titled “Best Practices and Case Studies for Chemical/Mechanical Management of Pipelines.” Here, the science and engineering principles described in the earlier sections are illustrated through practical demonstrations of chemical/mechanical intervention and remediation.
Thus, Chapters 1 through 4 describe the root problems and Chapters 5 through 8 provide a large range of mechanical and chemical solutions that can be accomplished in safe and environmentally acceptable ways.
Definition of the Pipeline Treatment Environment and Summary
The scope of this book is limited primarily to chemical/mechanical intervention and enhancement in the production (upstream) and transfer (midstream) oilfield environment. This includes flowlines and gathering lines, associated-gas/liquid-treating facilities, and US Department of Transportation–regulated crude-oil trunk and gas transmission pipelines. The discussion will not specifically include problems in refineries or finished product pipelines. However, many of the needed techniques and technologies, especially those for treating separation/gas-treating units, are similar to those described in this book and could be applied with appropriate modifications. See Frenier (2001) for a review of the cleaning of industrial equipment, including downstream oil/gas equipment. The scope is limited primarily to internal flow assurance and integrity issues. Note that external corrosion problems are usually addressed using cathodic protection and coating methodologies that are beyond the scope of this book. However, some in-line inspections will detect and assess exterior corrosion as well as the effectiveness of cathodic protection.
See Lazzari and Pedeferri (2006) for an explanation of cathodic protection and Munger and Vincent (1999) for discussions of protective coatings. Also see the comprehensive books on pipeline activities by Revie (2015), Peabody (2001), and Hevle (2012) and the Petrowiki (2014) web page.
