The pipeline industry

The offshore oU and gas industry is not the only one that is having problems improving its process safety record. In May 2013 the Pipeline and Gas Journal published an editorial— part of which is quoted below. 

API s annual liquids pipeline conference last month in sunny San Diego was instead a scene of uneasiness for many of those in attendance... the conference really culmimited with the terse announcement that there were no winners among large operators for API s prestigious Pipeline Distinguished Safety and Environmental Performance Award. Good for API, which has raised the bar to qualify for the award. None of them deserved to win. 

The article quotes a string of incidents—all suggesting an unfavorable trend. Major companies are named including Enbridge, Chevron, ExxonMobil, and Shell. Some of these companies have reported several events. Table 1.1 provides 

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The development of soil corrosivity assessment techniques has largely been due to the pipeline industry s requirements for better corrosion risk assessment and the reduction of pipeline failures. Corrosion in soil is a complex process and over the years several parameters have been identified as having a significant effect on the corrosion rate in a given soil. 

Perhaps the most widely known measurement technique is that adopted by the West German Gas Industry and developed by Steinrath for buried pipework. This assigns a value (See Table 2.20) to each parameter measured the summation of these values determines the corrosivity of the soil. The parameters measured are shown in Table 2.20. Although this technique was developed for the pipeline industry it can be used with some success for general soil corrosivity assessment. 

Overland Pipelines. Detailed maps of gas pipelines in the United States and other parts of the world can be found in several references, particularly among the periodicals serving the pipeline industry. Notable among these references is the international petroleum encyclopedia and atlas issued periodically by Petroleum Publishing Co., Tulsa, Oklahoma. Numerous trade associations serving the pipeline industry are also excellent sources on pipeline statistics, There are so many pipelines that presentation of this type of information is beyond the scope of this encyclopedia. 

As with other sectors of our society, the operating environment of the pipeline industry has been profoundly altered by September 11, 2001. Security has been elevated to a priority that previously had not been required when the major threat was an occasional and usually minor act of vandalism. In most cases, the threat with gas pipelines may be economic disruption more than public or environmental safety for most incident locations. The lines are buried through most of their runs and there may be more attractive surface targets. However, the threat is real and is being addressed. It is beyond the scope of this entry to elaborate in detail, but enhanced security measures are being evaluated and implemented throughout the industry. 

General Accounting Office (GAO). The Office of Pipeline Safety is Changing, How it Oversees the Pipeline Industry United States General Accounting Office Pipeline Safety, GAO/ RCED-00-128, May 2000. 

There are two reasons for the mystery. First, the world s major pipelines make rather lousy natural monopolies. On first examination pipelines do exhibit one traditional indicator of a natural monopoly, namely declining unit costs (larger pipelines will have lower unit costs than smaller ones). It is less clear if declining unit costs (or natural monopoly) plays a significant role in the structure of actual pipeline markets. The second problem concerns economists preoccupation with analyzing the pipeline industry in isolation. Pipelines themselves have utterly no value on their own - they... 

External corrosion problems in oil and gas production normally are similar to those found in the pipeline industry, but as the lines are shorter and smaller in diameter, their economic impact on the total cost of production is limited. Atmospheric corrosion of structures and vessels is a problem for offshore fields and those operating near marine environments. 

A combination of composite materials in conjunction with steel was introduced into the pipeline industry in the 1980s, when the application of composites overlaying steel sleeve became a standard for pipeline repairs. One of the most notable applications is that resulting from the collaborative efforts of Emon and the Gas Researeh Institute (GRl) in 1991, which resulted in installation of SSLP in their system. After eight years in service, the SSLP was inspected, and was verified to be in the same condition as in its initial state. Later on, TransCanada Pipelines Inc. also ventured into the use of SSLP pipes in several projects in 1998, 2001 and 2002 (Stephen, 2005). 

Nowadays, the use of FRP materials instead of the traditionally used steel sleeves for repair and rehabilitation of pipes has become quite popular. The most commonly used FRP pipeline repair materials consist of fibers such as glass and carbon, whereas the most commonly used resin is epoxy. FRP, with a combination of glass fibers and epoxy resin, is mostly used in the pipeline industry due to the following characteristics ... 

As a result of regulatoiy changes in the U.S., the pipeline industry needed an alternative method to pressure testing on in-line tool inspection to assess buried pipelines [33], EDCA is a four-step process consisting of ... 

The pipeline industry uses considerable resources to minimize the likelihood of failures. A study recently completed by the DOT Federal Highway Administration (FFfWA) estimates that the pipeline industry... 

External corrosion direct assessment (ECDA) is a structured process that consists of four key steps preassessment, indirect examination, direct examination, and post assessment (Fig. 12.16). ECDA is intended to assist pipeline operators in establishing the integrity of pipelines. The process uses aboveground cathodic protection (CP) survey methods, many of which have been used in the pipeline industry for decades. ECDA further defines the process, validation, and data integration for these survey methods [18]. The ECDA process incorporates standard techniques for compiling historical information, pipeline and soil surveys, external pipeline inspections, and data analyses. 

In-line inspection (ILI) tools, also commonly called "smart" or "intelligent pigs," are cylinder-shaped electronic devices used by the pipeline industry to detect loss of metal and in some cases deformations... 

Corrosion Protection. Although steel underground transmission lines are often protected by coal tar or fusion bonded epoxy coatings, a large volume of polyethylene tapes as well as some vinyl-backed tapes are used for corrosion protection. Pipes of large diameter, such as oil line pipes, are usually machine-wrapped in the field just prior to placement in the ground. The tapes are unusual in that the backing is from 12 to 15 mils thick and the butyl-based adhesive is approximately of the same thickness. For the pipeline industry the rolls are 18 in. wide and contain up to 800 feet of tape. There is a reduction currently in domestic pipeline construction but appreciable amounts of pipewrap are exported. 

The ESAB range of consumables for pipeline welding has been developed to match the steel qualities and the demands from the pipeline industry for reliable, easy to... 

In the pipeline industry, it is diffieult to autoelave a field-installed repair, and only a limited number of systems are available to post-euring at high temperatures however, the assoeiated cost is high compared to simply adding a few more layers. Developing an economical means to post cure a wrap remains an area of active research for the community. 

Finally, as composite repairs become more familiar to the pipeline repair industry, there is a high probability that the entire industry will become more standardized.. Similar to how the steel industry developed a common means of specifying steel strengths, such as American National Steel Institute (ANSI) and American Petroleum Institute (API) have established standards for pipe, there will be more standards instituted into the nonmetallic repair design by the pipeline industry to ensure that the repairs meet specified performance standards. 

Many composite overwrap repair systems have been introduced to the pipeline industry, their differences being in fibres, adhesive, resin and method of application. Carbon fibre, glass fibre and aramid fibre (Kevlar reinforcement) are the usual fibres used in these composite systems to provide for the required strength and stiffness. In general, two types of composite repair, namely layered system and wet lay-up system, are currently used for pipeline repair (Figure 10.1). 

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