Managing Pipeline Integrity

Pipeline operating companies have established processes:

  • to monitor current operations,
  • to monitor facility condition,
  • to carry out risk assessments
  • to respond to emergencies.

During these activities they have also created a strategic asset – information.

The following discussion explores the application of information integration (knowledge) to pipeline integrity management.

Applying Knowledge to Pipeline Integrity Management

Let’s for a moment look conceptually at what is involved in the application of knowledge to the management of pipeline integrity.

Peter Drucker in his book “The Post-Capitalist Society” discussed the meaning of knowledge. The discussion provides an historical framework and some insights on what is happening in organizations today. The following is paraphrased from the book:

The meaning of knowledge has changed over the centuries.

In the thirteenth century knowing things was an intellectual activity determining one’s personal image. In the late eighteenth century, technology, the systematic application of knowledge to developing mechanisms for producing things, was born and spawned the Industrial Revolution. During the past century, knowledge has been applied to work – the Productivity Revolution.

Today’s application of knowledge is to knowledge itself – the Management Revolution. Management is, therefore, seen as the application and performance of knowledge.

The basic economic resource – “the means of production,” to use the economist’s term- is no longer capital, nor natural resources, nor labor. It is and will be knowledge. Value is now created by “productivity” and “innovation” both applications of knowledge to work.

For the application of an area of knowledge to be effective, it must be highly specialized. However, isolated areas of knowledge are sterile. They become productive only if welded together into a single, unified knowledge. To make this possible is the task of the organization, the reason for its existence, its function.

In the early days of the pipeline industry, great reliance was placed on the experience-based skills of many long term employees who had seen how the line was originally built, who knew the local landowners well, and who had a way of working with other employees that relied on an inherent social structure. To a large degree, this culture has vanished in many pipeline companies due to mergers and acquisitions, right-sizing of staff counts along with the more competitive environment in which survival of the organization is often threatened. This evolution has applied to most industries, not only to pipelines.

To survive and prosper, therefore, it seems clear that organizations in general and pipeline companies in particular must apply knowledge to the use of knowledge. This will require comprehensive synthesis of information along with suitable visualization tools to augment the analytical processes that are more common today. Risk-based methodologies using site-specific risk and consequence information will be one of the beneficial applications of knowledge.

Risk-based Facility Management

The cost to transport gas, oil and petroleum products by pipeline is among the lowest of any energy transportation mode available. However, the cost to construct, operate and maintain a pipeline system is still enormous. Part of the cost is affected by the approach taken to achieving integrity of the facility. The industry has, in concert with governments, developed codes and regulations for the design, construction, operation and maintenance of pipeline facilities. In general these approaches (CSA, ANSI, ASME) use a “reference stress” approach based on the permissible hoop stress produced by internal pressure in the pipeline. Safety factors, developed through judgment, history and usage, are applied.

In the case of gas pipelines, for example, one of the safety factors derives from the application of so-called class locations. This somewhat arbitrary approach assigns a value depending on the range of population density found in that locality. The result is that thicker wall pipe is installed at greater cost in locations where population density is highest. The inherent assumptions are that this is the only way to lower the risk/consequence appropriately and that it is sufficient. But thick pipe can corrode at the same rate or faster depending on other factors such as pipe material, coating, soil conditions etc. Conceptually, an alternative approach could be to eliminate the class location factor altogether and to achieve the required level of pipeline integrity through periodic in-line inspection in high population density areas. Combining the in-line inspection information with other site-specific information regarding risks and consequences would allow site-specific risk-based decisions to be taken. The viability of this alternative requires additional study and is given here only as an example of how site-specific knowledge can be applied.

The benefits of a risk-based approach have been recognized. In the United States, the Office of Pipeline Safety is initiating a risk-based approach to their regulatory activities. This is expected to produce a more proactive rather than reactive approach. In Canada, the Z183, Z184 and Z187 codes have been combined into one comprehensive code – Z662. It allows the use of the so-called “limit states” approach as a non-mandatory alternative to the traditional approach. This is a risk-based approach. It will be able to deal with a range of site-specific risks of failure as well as a range of site-specific consequences (e.g. wetlands).

To be effective in the next decade and beyond, pipeline companies will need to use risk-based approaches in the design, construction, operation and maintenance of facilities. This will require:

  1. Well organized and accessible information on a site-specific basis regarding all real and potential threats and consequences (e.g. design, construction, operation & maintenance records; in-line inspection; SCADA, aerial patrol; remote sensing; property owners; population demographics; environmentally sensitive areas). For internal purposes, this could be extended to include site-specific information regarding the company’s overall strengths and weaknesses and its real and perceived business threats and opportunities.

  2. Delivery of this information to personnel distributed across the organization in a manner appropriate to the individual’s particular responsibility. This could be extended at the company’s discretion, to provision of certain information to outside parties with valid interests in particular aspects of the company’s operation (e.g. BBS for nominations, ties to emergency response forces).

  3. Integration, synthesis, visualization and analysis tools (e.g. expert systems) that achieve consistent and optimal results supporting cost-effective responses and decisions.

Pipeline Integrity Management

The term “Pipeline Integrity” has been used widely to describe the issues and processes that are involved in managing the life cycle of the pipeline so that pipeline failures are minimized and the life expectancy of the facilities is maximized. This is an example of a risk-based site-specific application of knowledge about the pipeline. Let’s take a look at what the management of “Pipeline Integrity” involves.

Failure Causes:

Failure mechanisms that can lead to loss of pipeline integrity have been identified. Among them are; internal corrosion; external corrosion; outside force or third party damage; and construction/operating errors.

The effective management of pipeline integrity requires an extensive information base along with good technical/economic analysis capabilities. The information needs to be adequate in precision and extent to identify and quantify all significant risks and related consequences in site-specific terms. There must also be a capability to determine the extent or probable extent of the problem through correlation with site-specific information about the design, materials, construction method, operating history and maintenance history.

Most of the required information sources and technologies to support this environment are available today and continue to evolve at a remarkable rate. Let’s take a look at them in more detail.

Information Technology and Connectivity

A key to success is clearly the application of information technology. Computing hardware and software continue to develop at a dramatic pace. Inexpensive desktop PC, workstation and server hardware are available today. Client-server architectures are maturing that will allow effective distribution of function between the desktop machine (the client) and centralized servers. Standards are being developed for open connectivity between hardware and software platforms that will make the investment in these systems transportable and will not bind a company to a single vendor solution.

GIS/AM/FM Systems

A Geographic Information System (GIS) allows a computer-based model of the pipeline to be developed which gives a geo-reference to each point along the pipeline. A common location framework enables all pipeline facility data to be readily cross referenced. GIS systems incorporate features that allow selective assimilation of various types of information. Subsequent graphical presentation of the results on a computer screen permits the user to visualize the nature, extent and location of the issue at hand.

GIS systems are in wide spread use in the construction of new pipelines. The improved productivity in route selection, alignment sheet preparation and right-of-way activities has been well recognized. The application of GIS to pipelines is evolving in sophistication. 

Some companies have also converted their existing facilities records for inclusion in a comprehensive on-going facilities management system. GIS/AM/FM is a key technology needed to integrate the various kinds of facilities information.

Risk Management Techniques

Risk-based approaches prioritize where resources should be allocated in order to maximize benefit. Pipeline risk management approaches continue to evolve. An approach to building a risk model has been presented by W. Kent Muhlbauer.

In this approach, multiple attributes are evaluated along with assigned relative importance weightings to derive the respective indices for each pipeline section. By combining the indices along with a leak impact factor, a relative risk score is developed for that section.

In-Line Inspection Tools

Many pipeline operators utilize in-line inspection technology (sometimes called “Smart Pigs” or “Intelligent Pigs”) as part of their pipeline integrity programs. The tools are designed to travel through the pipeline propelled by the product flow. They are self-supporting containing on-board battery power, sensors and data acquisition systems. As they travel through the pipeline, the tools acquire detailed site-specific information about certain aspects of the pipeline condition. After the journey through the pipeline, the data are retrieved and analyzed, often using computer aided processes.

In-Line Inspection Tools are available from a range of vendors such as:

Baker Hughes – a GE Company
TDW In-Line Inspection
NDT Systems & Services

to measure geometrical deformation, internal/external corrosion, crack-like defects, position/movement and other factors that affect pipeline integrity.            

In-line inspection tools strive to accurately detect, quantify and locate all defects accurately which could cause pipeline ruptures and leaks. Early warning of active deterioration also allows the pipeline manager to address the related root cause at an early stage, thus preserving the investment in the facility.

The types of defects which cause service failures have been well documented. The ultimate goal in developing in-line inspection tools should be to achieve a sufficient level of accuracy and reliability in in-line surveys so that pipeline managers can adequately assess the relevant defects and confidently make cost-effective decisions regarding repairs, replacements, and preventive maintenance directly from the survey results.


Pipeline operators have applied modern technology and techniques to the design of facilities and to the preparation of operations and maintenance plans and procedures. They have established processes to monitor current operations, monitor facility condition, carry out risk assessments and respond to emergencies. To be effective in the next decade and beyond, pipeline companies will need to use risk-based, site-specific approaches in the design, construction, operation and maintenance of facilities. This will require:

Well organized and accessible information on a detailed site-specific basis regarding all real and potential risks and consequences.

Delivery of this information to personnel distributed across the organization in a manner appropriate to the individual’s particular responsibility.

Integration, synthesis, visualization and analysis tools that achieve consistent and optimal results supporting cost-effective responses and decisions (i.e. – the management of knowledge).

The application of knowledge to pipeline management and to pipeline integrity, in particular, will be of strategic importance in guiding the destiny of pipeline operating organizations.