World's pipeline industry, while safe and reliable, must learn to cope with change

Robert J. Reid
President
Canadian Mainline, TransCanada Energy Transmission Ltd.
Calgary

The following is based on keynote remarks made to the 1998 International Pipeline Conference, Calgary, June 7-11.

Well into the next millennium, change is likely to be the only constant for the international pipeline industry. Its direction is being shaped by diverse, complex factors, including increased competition among pipeline companies, unparalleled technological change, a changing regulatory climate, and higher public expectations on safety and environmental issues.

Pipeline safety

For pipeline companies worldwide, success depends on providing safe, reliable transportation of natural gas and liquid hydrocarbon products. Public perception must also be that the industry is technically competent at ensuring pipeline safety.

In fact, pipelines are by far the safest method of transporting the huge volumes of hydrocarbon products consumed each day.

In Canada, the Transportation Safety Board earlier this year released its 1997 safety statistics that compare commodity pipelines with the country's three most common modes of transportation-air, marine, and rail.

In 1997, the board reported, Canadian-registered aircraft recorded 408 accidents, with 85 fatalities. There were 583 marine shipping accidents, with 24 fatalities. Railway accidents numbered 1,125, with 107 fatalities. For commodity pipelines, on the other hand, there were 27 pipeline incidents last year, with no fatalities. In fact, there has been no fatality reported on a commodity pipeline in Canada for the past 9 years.

But the industry must not rest on past success and must do a better job of sharing this information with the public. Pipeline companies throughout the world are addressing the complex issues surrounding pipeline safety and integrity.

Stress corrosion cracking

For several years in Canada, stress corrosion cracking (SCC) has been a major focus for regulators and pipeline operators. But SCC has also been identified as a cause of pipeline failures in the U.S., France, Australia, Iran, Iraq, Italy, Pakistan, Saudi Arabia, and the former Soviet Union.

In Canada, it has caused 22 pipeline failures since 1977. During 1985-95, SCC was responsible for 17% of the in-service ruptures experienced by Canadian pipeline operators.

Although SCC is not the primary cause of pipeline failure in Canada, the rising number of SCC-related incidents resulted in 1996 in a National Energy Board (NEB) inquiry. The resulting report, released in December 1996, provided valuable scientific and technical data that focused on the Canadian situation. But its findings can also be applied to SCC challenges experienced by pipeline operators worldwide.

Among its several recommendations, two have since become part of a series of strategic initiatives by the Canadian Energy Pipeline Association (CEPA).

The first, involving development of a manual of recommended practices for managing SCC, was designed to help pipeline operators develop SCC integrity-management programs tailored to their unique systems.

The second initiative concerns the formation of an SCC database that allows operators to input SCC data obtained from in situ field investigations.

These data will enhance understanding of SCC and help identify future research needs. Beginning this summer, non-CEPA members have also been able to contribute to the database.

General corrosion

Following this success in managing SCC, the Canadian pipeline industry is now broadening its efforts to include other areas, such as general corrosion-which accounts for about 25% of ruptures on Canadian pipelines. This figure is in line with statistics for other countries.

To help its members, CEPA initiated a corrosion-management survey of member companies.

The first phase of this project involves gathering relevant data through a detailed questionnaire of the corrosion-management practices currently being used by CEPA member companies.

Results will be tabulated this fall with CEPA's Integrity Management Working Group.

Although early, the results may lead to development of recommended practices or guidelines for corrosion management, similar to recommended SCC practices.

An increasing number of incidents involving external corrosion has also prompted action in other jurisdictions.

To address this problem, the U.K. has launched a 3-year program sponsored by British Gas plc, seven major oil and gas companies, two regulatory groups, the Health and Safety Executive of the U.K., and the Norwegian Petroleum Directorate.

The program's objective is to provide guidance for assessing future reliability of pipelines with corrosion defects. It is based on information developed from rigorous analytical studies that have been validated through a program of full-scale and small-scale experimental burst tests. This will allow the program's assessment methods to be applied with confidence to other pipe and corrosion features.

Risk management

These examples make clear that safety is a top priority for pipelines worldwide; each year, the industry commits much of its resources to maintaining and improving safety.

Among the tools for ensuring pipeline integrity, one of the most successful is risk management. Risk management requires detailed reviews of how we operate and maintain pipeline systems. This, in turn, provides an analytical overview that helps pinpoint sources of risk that may not be recognized in systems based on regulatory compliance. Risk management helps decision-makers identify and prioritize effective risk-reduction measures.

For years, risk analysis has been used by pipeline operators in the U.K. and France to assess the need for pipeline diversions, proximity infringements, uprating, etc. The U.K.'s new Pipelines Safety Regulations support development of risk-analysis programs. Western Europe and Australia are also moving in this direction.

In Canada, risk assessment and risk management have been promoted by the Pipeline Risk Assessment Steering Committee (Prasc), formed in 1995 and including members from pipeline associations, regulators, and the public. Prasc has developed a Canada-wide database of reportable pipeline incidents and characteristics. Cataloging the nature and causes of past failures will provide a key to predicting risk of future pipeline incidents.

To implement risk concepts, a nonmandatory appendix, "Guidelines for Risk Analysis of Pipelines," was included in the Canadian Standards Association standard Z662 for 1996. For 1998, the risk concepts are being strengthened to include risk evaluation.

In the U.S., several serious pipeline incidents have increased interest in risk-assessment practices. The Department of Transportation's Office of Pipeline Safety initiated work with the industry to improve pipeline safety. Risk Assessment Quality Teams were established to develop a plan for including risk assessment in U.S. pipeline regulations.

Risk assessment may lead to greater flexibility for pipelines in meeting safety rules.

New technologies

Significant changes in technology have improved how pipelines are built, monitored, and their flows controlled and have made our services more efficient and effective.

Technology is answering many complex questions involving pipeline safety and integrity. For example, years of research and development have created highly sophisticated in-line inspection devices-intelligent pigs-that have improved the ability to inspect the internal integrity of pipelines.

Special inspection tools that use ultrasonic technology are currently being designed for detecting all types of cracking, including SCC.

CEPA, the Pipeline Research Committee International, Gas Research Institute, and British Gas initiated research in 1995 to develop a new-generation, crack-detecting in-line inspection tool using British Gas's technology. These 24-in. and 42-in. tools should be available by yearend. Crack detecting, in-line inspection tools will likely evolve to a reliability comparable to that of hydrostatic testing in finding near-critical cracks.

We also encourage technology developments by other service providers of intelligent pigs: EMAT (Electromagnetic Acoustic Transducer) and other ultrasound-based approaches, as well as magnetic flux leakage (MFL) concepts to detect cracks.

Regulators recognize the technological benefits of intelligent pigs. In the U.K., regulators responsible for pipe- line safety encourage pipeline operators to build pipelines that can be inspected by intelligent pigs. In Canada, one outcome of the SCC inquiry will be new regulations requiring new, large-diameter transmission pipelines be designed and built to accommodate in-line inspection tools.

Technological advances have also resulted in new pipeline construction methods that use high-strength steels. X-80 line-pipe steel has been used in several installations, and X-100 is possible for future projects. These materials have several advantages. Their strength allows them to withstand high operating pressures. High-strength steels also reduce wall thickness, which means less weight and shorter welding times. Together, these advantages translate into greater durability and lower overall construction costs.

In the U.K., British Gas has successfully used X-80 line pipe for offshore installations and is planning to use this material in future large onshore projects. In Germany, Ruhr Gas AG has also built an X-80 pipeline. In Canada, Nova Gas Transmission has built more than 300 km of large-diameter pipelines with X-80 steel. TransCanada PipeLines introduced X-80 on its billion-dollar expansion this year and plans to use it in future.

Design changes

Advances in pipeline materials have prompted changes in pipeline design.

In the U.K., pipeline operators are using new analytical methods to support increased operating pressures for transmission pipelines. Changes in the U.K. regulatory environment made this approach possible.

In 1996, the U.K. Health and Safety Executive, responsible for pipeline safety, introduced new Pipeline Safety Regulations. These require operators to demonstrate that risks from operating of pipeline have been reduced to "as low as reasonably practical."

This new regulatory environment has allowed companies, such as British Gas, to explore higher operating pressures with a "limit-states" design approach. Defined simply, it is a risk-based method that incorporates failure probability for pipeline system segments.

In certain circumstances, limit-states design can allow higher operating pressures. British Gas has been able safely to uprate segments of its transmission system from 72% specified minimum yield strength (SMYS) to 78% SMYS with no increase in risk. Several European nations are monitoring this concept. In Canada, the 1996 Canadian Standards Association pipe- line code incorporates a limit-states design non-mandatory appendix that provides pipeline construction guidelines for limit-states design.

Climate change

Aside from pipeline safety and integrity and technological advances, one other issue holds serious implications for this industry: climate change.

Canada agreed to cut by 2008-12 its greenhouse gas emissions to 6% less than 1990 levels, a difficult target.

By 2010, emissions will likely be 19% greater than in 1990, meaning Canadians will have to reduce projected emissions by 25% to meet the Kyoto target.

During 1990-96, natural gas volumes transported by CEPA companies jumped by 56%, while crude oil deliveries rose by 32%. These incremental volumes were exported to the U.S. to replace high-carbon fuels, thus reducing emissions in that country.

This high growth rate, however, has increased emissions in Canada since 1990 by about 34%. Because of increased consumer demand for the products we transport, our industry expects this growth to continue.

Canadian pipelines have been successful in limiting their emissions growth. Since the start of the federal program in 1994, it has limited emissions increases to less than 1%. That's significant, considering that deliveries of natural gas and crude oil increased by 11% and 15%, respectively. Canadian oil and natural gas pipelines have also achieved many energy efficiencies.

As capital stock is retired and replaced, companies are selecting state-of-the-art low-emission technology.

It would be financially imprudent, however, to replace all equipment at once to meet short-term reduction targets. Even to come close to meeting the Kyoto objective, we will need significant technological breakthroughs in order further to reduce emissions.

The Author