Introduction

The Office of Pipeline Safety (OPS) was established over 32 years ago in the U.S. Department of Transportation (DOT). Since then, there have been many changes in the regulatory and research environment. This paper presents some of the issues and events which have resulted in changes to OPS over the years. The paper provides descriptions of past and present OPS research and an insight into the factors which will most likely shape future research. The paper includes details of past and future OPS in-line inspection, or pigging, research.

Evolution of OPS

The Office of Pipeline Safety (OPS) was 32 years old in September 2000. There have been many changes over these years, not only in the research program, but in the emphasis placed on the safety regulations, enforcement of the regulations, and the creation of other programs. This paper begins by presenting an overview of many of the significant changes which have occurred in OPS.

OPS was directed by Congress to establish permanent safety standards covering natural gas pipelines within two years of passage of the Natural Gas Pipeline Safety Act of 1968 (NGPSA). The professional personnel of the original twenty-two person staff consisted of engineers, most with operating pipeline experience, and one attorney to keep the engineers on a legal track. As it turned out, the standards were issued on August 11, 1970, one day before the congressional deadline. Once the standards were established, a period began of educating pipeline operators, especially small pipeline operators, concerning the contents of the new regulations. This was followed by establishing a field staff, first in Houston, then in four other locations throughout the country to enforce the regulations ⁽¹⁾.

The office has blossomed, particularly in the last few years, and is now involved in programs which enhance the basic safety standards and the enforcement of these standards. Most of these programs have been mandated by Congress in the legislation which re-authorizes the pipeline safety program every few years. The following illustrate the changes that have taken place and the major initiatives undertaken by OPS in recent years:

Personnel changes. The OPS staff has increased from 20 authorized positions in 1968 to 109 authorized positions today. However, this increase doesn't reflect the recent use of contract staff, which now supports the OPS programs. In January 2001 there were 36 full time federal employees located in the Washington, DC headquarters and 66 full time federal employees located in the five regions. There were 15 contractor personnel supporting the program. In addition, there are now more than 300 state pipeline safety inspectors. In 1968, there were no state programs under the NGPSA whereas today there are state programs for intrastate gas in 48 states, the District of Columbia and Puerto Rico, and programs for intrastate hazardous liquid in 15 states. If the federal workers, contract workers, and state workers are added together, there are approximate 420 persons working on the pipeline safety program.

Size and makeup of the budget . The budget has increased from $250,000 in 1968 to $47,044,000 in Fiscal Year 2001. In the first few years, the emphasis was on salaries. Later OPS initiated a statutorily mandated grant-in-aid program to reimburse state organizations a portion of the money they spend to administer the pipeline safety programs. This grant-in-aid program makes up 35 percent of the Fiscal Year 2001 budget. A new grant-in-aid program, amounting to 10.6 percent of the Fiscal Year 2001 budget, has been added to assist the states in administering a one-call damage prevention program. A major goal of the Best Practices program, which spawned the one-call damage prevention grants, is to encourage states to adopt one-call notification programs that meet minimum standards established by law ⁽²⁾. The amount of money budgeted for research has also increased. In 1970, the first year of any research, the amount of money obligated to research was $308,000, whereas in the Fiscal Year 2001 budget, it is $2,744,000. This small research budget, relative to other federal agencies, reflects the limited research authority Congress has granted OPS and is one reason OPS today is seeking research partners to leverage the funding. The policy on research has changed over the years. Much of this paper addresses that change.

Risk management plans for pipelines. OPS, along with state regulators, pipeline operators, and local safety officials, is investigating risk management programs as an alternative to the established pipeline safety regulations. The Pipeline Risk Management Demonstration Program, authorized by the Accountable Pipeline Safety and Partnership Act of 1996, is designed to test whether a structured and formalized process for identifying pipeline-specific risks, allocating resources to the most effective risk control activities, and monitoring safety and environmental performance can lead to superior safety and environmental protection. The Demonstration Program is testing these assumptions in no more than 12 Demonstration Projects being conducted by interstate pipeline operators. So far, risk management programs of Chevron Pipe Line, Equilon Pipeline, ExxonMobil Pipe Line, Kinder Morgan, Inc., Phillips Pipe Line, and Northwest Pipeline have been approved for inclusion in the Demonstration Program.

National Pipeline Mapping System (NPMS). As a joint government-industry effort between OPS other federal and state agencies, and the pipeline industry, the NPMS is a full-featured geographic information system (GIS) database that will contain the locations and selected attributes of natural gas transmission lines, hazardous liquid trunk lines, and liquefied natural gas (LNG) facilities. The NPMS is being created from voluntary submissions of pipeline and LNG facility data by pipeline operators. The NPMS repositories are responsible for collecting, processing, and building a national, seamless pipeline database from the submitted data.

Damage prevention imitative. In 1998, Congress directed DOT to identify "best practices" for preventing damage to underground facilities, and for ensuring their safe operation. To fulfill this mandate, as authorized by the Transportation Equity Act for the 21^st Century (TEA-21), OPS undertook an unprecedented collaboration involving a broad spectrum of damage prevention stakeholders.

For nearly a year, more than 160 experts -- representing industries, community interests, and professional groups -- worked in teams on the Common Ground Study to identify, define and agree on more than 130 best practices for damage prevention. The report "Common Ground Study of One-Call Systems and Damage Prevention Best Practices" was delivered to the Secretary of Transportation in June 1999 at a public meeting in Washington, DC. From this effort, the non-profit organization Common Ground Alliance with membership from all underground utility entities has been formed. It is dedicated to continue the damage prevention efforts begun during the Common Ground Study to address the protection of the nation's underground infrastructure from outside force damage.

Integrity management programs. OPS is requiring that an operator develop and follow an integrity management program that provides for periodic assessment of the integrity of all pipeline segments that could affect high consequence areas, through internal inspection, pressure testing, or other equally effective means. A recent final rule ⁽³⁾ required pipelines to assess, evaluate, repair and validate through comprehensive analysis the integrity of hazardous liquid pipeline segments that, in the event of a leak or failure, could affect populated areas, areas unusually sensitive to environmental damage and commercially navigable waterways.

Hazardous liquid operators must comprehensively evaluate the entire range of threats to each pipeline segment's integrity by analyzing all available information about the pipeline segment and consequences of a failure on a high consequence area. This includes analyzing information on the potential for damage due to excavation; data gathered through the required integrity assessment; results of other inspections, tests, surveillance and patrols required by the pipeline safety regulations, including corrosion control monitoring and cathodic protection surveys; and information about how a failure could affect the high consequence area. The final rule requires an operator to take prompt action to address the integrity issues raised by the assessment and analysis.

Environmental legislation. Hazardous liquid pipeline spills are a safety concern, but the damage to the environment from these spills often is of greater consequence than the casualties. Prior to 1992, DOT's jurisdiction was limited to safety. In 1992 Congress expanded DOT's jurisdiction under the Hazardous Liquid Pipeline Safety Act (HLPSA) ⁽⁴⁾ to include environmental protection. It was also expanded under the NGPSA. The environmental amendments required OPS to: (1) mandate that operators submit safety-related condition reports on hazardous to the environment; (2) consider a hazardous liquid pipeline's proximity to "unusual sensitive environmental areas" when determining the type and frequency of testing and inspection required of operators; (3) consider the extent to which the operator's inspection and maintenance plan protects the environment; and (4) design any pipeline safety standard to protect the environment. (1) ⁽⁵⁾

User fees. The Consolidated Omnibus Budget Reconciliation Act of 1985 authorized the Secretary of Transportation to collect user fees from all pipelines subject to the jurisdiction of the NGPSA and the HLPSA in order to recover the costs incurred by DOT in administering the pipeline safety program. The user fee assessment for Fiscal Year 2001, which began on October 1, 2000, is $84.57 per mile for natural gas transmission pipelines and $73.83 per mile for hazardous liquid pipelines. One result of the user fee method of financing the pipeline safety program is a more active interest by the pipeline industry in the operation of the pipeline safety program.

The Influence of Major Failures

Major events often change the focus or direction of a policy. In the case of a safety program, such as the pipeline safety program, a major failure or accident often redirects the program. This redirection often takes the form of a change in the emphasis of the program, the number of people involved, and the amount of funding for the program, including funding for research. Following are descriptions of some of the major accidents which have occurred over the life of OPS which have resulted in a change in direction to the program including the research effort of the program -

Natchitoches, LA, 1965. The gas pipeline safety program was started because of a major accident in 1965 in Natchitoches, LA where failure of a major gas transmission pipeline resulted in 17 fatalities. In response to this failure, President Lyndon Johnson, in his State of the Union Address in January 1967, stated that he would propose measures to Congress to assure that there was safety in natural gas pipelines across the nation. The NGPSA and the formation of OPS resulted from President Johnson's address.

Mounds View, MN, 1986. Unleaded gasoline was released from the longitudinal seam of an 8-inch steel pipeline operated by Williams Pipe Line Company on July 8, 1986, in Mounds View, MN. Gasoline flowing down neighborhood streets ignited about 20 minutes after the break and spread through the neighborhood. Two persons were severely burned and later died. One other person suffered serious burns. Property damage was estimated at $1.4 million and both soil and water pollution occurred as a result of the 493 barrels spilled. The pipeline, installed in 1957-58 was being operated at 1,434 psig. (2) OPS was criticized for the lack of a field force to respond to such accidents. This resulted in a dramatic increase in the number of inspectors assigned to each of the five regions. Also, as a result of this accident, a number of legislative proposals were introduced in Congress to improve pipeline safety, including some which would require use of instrumented pigs, although the Williams failure could not have been prevented by pigging. (3)

Reston, VA, 1993. On March 28, 1993, Colonial Pipeline Company experienced a release of 8,000 barrels of diesel fuel on its 36-inch products pipeline, near Reston, VA. The released product entered the Sugarland Run, a tributary of the Potomac River. Approximately 7,400 barrels of product were recovered by a series of containment barriers. An unknown amount of product entered the Potomac River, resulting in the closure of the Fairfax County, Virginia water intake. Approximately 41 local residents voluntarily evacuated their homes. The cause was determined to be excavation damage from prior years. (4)

Edison, NJ, 1994. On March 23, 1994, a 36-inch natural gas pipeline failed and caught fire in Edison, NJ. The failure was caused by mechanical damage that resulted in a crack in a gouge on the exterior of the pipe, which over time grew to a critical size. The failure of the 36-inch pipeline operated by Texas Eastern Transmission Corporation (TETCO) resulted in the escaping gas igniting and creating a fireball 500 feet high. There were no deaths attributed directly to the failure, but there were approximately 50 injuries. Radiant heat from the fireball ignited the roofs of buildings located more than 100 yards from the failure, destroying 128 apartments and resulting in the evacuation of 1,500 people. The casualties were limited because the few minutes between the time of the failure and the explosion allowed residents to vacate the area. The gas company using a manually operated valve took 2½ hours to isolate the ruptured section of pipeline, which contributed to the severity of the damages. As a result of this failure, DOT convened the National Pipeline Safety Summit in Newark, NJ, which will be addressed in this paper under the heading "Present Research."

Bellingham, WA, June 1999 . On June 10, 1999, a rupture occurred on Olympic Pipeline's 16-inch Olympic hazardous liquid (gasoline) pipeline located near Bellingham, Washington (approximately 75 miles north of Seattle). Approximately 6,600 barrels of unleaded gasoline entered the Whatcom Creek and ignited, resulting in three fatalities and eight injuries. Whatcom Creek crosses through the city of Bellingham. The cause was determined to be outside force damage. OPS proposed a $3.05 million civil penalty against Olympic Pipeline for safety violations related to the pipeline failure. This was the largest proposed civil penalty in the history of the pipeline safety program. This failure also generated major public and Congressional interest and concern for the adequacy of the pipeline safety program.

Carlsbad, NM, August 2000. At 5:30 a.m. local time, on Saturday, August 19, 2000, an El Paso Natural Gas Company (ELPNG) 30-inch gas transmission pipeline ruptured and ignited at a river crossing in a rural area approximately 30 miles southeast of Carlsbad, N.M. Carlsbad is approximately 275 miles south east of Albuquerque, N.M. The 12 fatalities, all people camping next to the river, were the most from a transmission pipeline failure since the beginning of the pipeline safety program. The ruptured pipeline is 30-inches in diameter and was built in 1950. Significant areas of internal corrosion were found in the ruptured pipe.

Past Research

Appendix A lists most of the research activity in OPS since its inception in 1968. Data on much of the earlier research listed in Appendix A came from the annual reports to Congress required by the NGPSA. The summaries on research from those reports were brief and information was often sketchy so that the Appendix contains the statement "not readily available" for many of the research projects listed. However, the main purpose for Appendix A is to provide examples of the type of research which has been conducted by OPS.

The term "past research" is meant to describe research conducted from 1968 to 1990. There was a definite shift in emphasis in OPS in the 1990s including more collaboration with the pipeline industry, government-industry partnerships, more interaction with other federal agencies and state agencies, greater public participation in the program, a change in emphasis from the compliance model of regulation to a risk management approach, and, most recently, to an integrity management approach, and a greater funding for research, particularly after the 1994 Edison, NJ failure.

Appendix A shows that most of the past research was conducted to help OPS learn the state-of-the-art in a particular pipeline function, provide technical assistance in a particular engineering disciple where OPS did not have the in-house expertise, develop operating systems for the office, respond to a failure investigation, or respond to Congressional direction. Appendix A does not address the funding level for this research, but it has been low compared to many federal agencies, usually less than $1.0 million per year, until after the 1994 Edison accident. OPS is not now and never has been a research organization. Research is not mentioned in either the NGPSA or the HLPSA. This may change as addressed under Future Research in this paper. Therefore, it's understandable that our budget for research is small and the scope of research projects is limited.

Present Research

As mentioned in the previous section, there were a number of significant changes in OPS in the 1990s and early 2000s. There were also changes in the way research was funded and conducted. The three most significant events in the 1990s were the Reston, VA failure in 1993, the Edison, NJ failure in 1994, and the action by the Federal Energy Regulatory Commission (FERC) to phase out funding for the Gas Research Institute (GRI) ⁽⁶⁾ from surcharges on interstate gas.

The Edison failure was a major pipeline failure in terms of publicity, Congressional interest, and related OPS action. Although there were no deaths resulting directly from the failure, there was a great potential for a catastrophe - 128 apartments were destroyed and 1,500 people were evacuated. As a result of this failure, DOT convened the National Pipeline Safety Summit in Newark, NJ, which brought together federal, state, and local government officials, the pipeline industry, academia, environmental groups, business, and the general public. At that meeting, Secretary of Transportation Peña unveiled his vision for pipeline safety following the failures in Reston and Edison which included that: (1) every pipeline be tested or rehabilitated to ensure its integrity; (2) every state must have an adequate one-call system; (3) new technologies must be applied to monitor pipelines to detect serious flaws; (4) every community must have a land use policy involving pipelines; and (5) the federal government's pipeline safety program must enjoy strong public confidence, trust, and have the will and resources to address any risks that arise. (1)

Congress reacted by increasing the appropriations for research in fiscal year 1995, which provided funds for the research which is included in Appendix A conducted by the New Jersey Institute of Technology, Texas A & M, the Federal Emergency Management Agency, and Battelle/Southwest Research Institute/Iowa State University. Because this conference is focused on pigging, this paper will address only the research conducted by Battelle/Southwest Research Institute/ Iowa State University.

The funding for research conducted by GRI was from revenues collected through uniform volumetric surcharge on all throughput of interstate natural gas pipelines. This changed in 1997 with the beginning of phase-out, which will end in 2004. One of the outcomes of this funding change was a 1996 Memorandum of Understanding (MOU) between GRI and DOT. The objective of the MOU is "to define and formalize a structure to exchange information and coordinate DOT's and GRI's gas [research, development, and commercialization] programs."

The first research conducted under this MOU was with Battelle, including the Southwest Research Institute and Iowa State University, to advance the in-line inspection (ILI) technology of magnetic flux leakage (MFL) to identify and characterize mechanical damage. The 40 month, $3.1 million contract, the largest ever funded by OPS, was funded entirely by DOT with technical assistance and advice provided by GRI. The research is significant not only because of its scope, but because it addresses a form of non-destructive evaluation that is the cornerstone of OPS' integrity management programs in high consequence areas. Early payoff from this research was that a pig vendor, based on the results of the research, built a prototype tool leading toward commercialization of the technology.

MFL is the most commonly used ILI method for the detection of corrosion in pipelines. Extending this technology for mechanical damage would simplify deployment and have many practical and economic benefits. MFL inspection tools locate pipeline defects by applying a magnetic field in the pipe wall and sensing a local change in this applied field with sensors near the pipe wall. These changes depend on the type of defect (metal loss or changes in material or magnetic properties). MFL has been shown to be capable of detecting some mechanical damage. Part of the signal generated at mechanical damage is due to geometric changes. Other parts of the signal are due to changes in magnetic properties that result from stresses, strains, or damage to the microstructure of the steel.

Mechanical damage is the single largest cause of failures on gas transmission pipelines and a leading cause of failures on hazardous liquid pipelines. The mechanical damage usually occurs after a pipeline is constructed and is caused by excavation equipment which deforms the shape of the pipe, scrapes away metal and coating, and changes the mechanical properties of the pipe.

The research by the Battelle team focused on determining the severity of defects and the likelihood of them threatening the integrity of a pipeline. This was accomplished by producing a number of defect sets and testing them in the 300-foot pull rig and, under realistic pipeline conditions, in the 4,700-foot flow loop, at GRI's Pipeline Simulation Facility (PSF) near Columbus, Ohio. Pressure affects MFL signals by introducing stresses, which are known to affect MFL signals at mechanical damage. Also, operating conditions inside a pipeline are rugged, which makes application of sensor technologies difficult. Flow loop tests were conducted to determine the effects of stress and pressure on mechanical damage signals and to calibrate the prior results taken under unpressurized conditions.

The Battelle team used feature-based analysis to conduct its research. Feature-based analysis methods make use of discrete signal parameters, such as peak amplitude or peak-to-peak amplitude. Peak amplitude is the maximum recorded value in an inspection signal, and peak-to-peak amplitude is the difference between the maximum and minimum recorded values in an inspection signal. Feature-based analysis methods are commonly used by inspection vendors today.

The goal of the work on feature-based methods was to obtain signals that increase the probability of obtaining a measurable signal from significant mechanical damage and properly differentiate these signals from other "anomalous" signals or decoupling the signal. The primary reason for decoupling the MFL signal is to reveal the presence of cold working. A defect with a cold worked area yields a distinct signature in the magnetic component of the MFL signal. This signature is often overshadowed by the defect's geometric component, and so, a decoupling method was developed to make the signature more distinguishable. Decoupling allows further analysis of the signal components to assess the severity of the defect.

Two other methods of assessing mechanical damage were investigated in this program. The first, nonlinear harmonics ⁽⁷⁾, seeks to measure the residual stresses and plastic deformation around a damaged region. The second, neural networks ⁽⁸⁾, is an alternative method of identifying and

characterizing damaged zones.

The Battelle team evaluated the use of nonlinear harmonic inspection methodologies for detection and characterization of mechanical damage. The results showed that there is good detection of defects but that there is not a clear indication of the severity of the defect in the nonlinear harmonic signal amplitude. Consequently, nonlinear harmonics may be

best used as a complement to other inspection methodologies rather than as a stand-alone technique.

A feedback neural network scheme was investigated for characterizing defect geometry. The research concluded that the technique is capable of predicting the defect profiles reasonably well.

The Battelle team further concluded that MFL tools for mechanical damage will need to contain multiple types of sensors and inspection systems. At least two different magnetization levels are needed to separate signal components due to geometric changes and magnetic changes near the damage. By decoupling signal components, detection and sizing algorithms can concentrate on damage components that are most related to defect severity. Combining results from different types of sensors should allow much more robust inspection capabilities. The goal is to conduct a single ILI tool survey through a pipeline to identify and characterize corrosion and mechanical damage.

The Battelle team's final conclusion was that development of more robust techniques for characterizing mechanical damage requires field experience and close coordination between further development of inspection methodologies and research into the conditions that make defects critical ⁽⁹⁾.

Future Research

The research effort in OPS in the new millennium appears to be changing from what it was in the past. There are at least five elements of this change -

More collaborative research. There will be more collaboration by OPS with other government agencies and the industry than in the past. This benefits everyone by avoiding overlap and waste in research projects. One example of this on the industry side is the MOU established with GRI that was mentioned earlier. An example on the government side is the shared research that OPS has participated in with the Mineral Management Service (MMS) of the Department of the Interior (DOI). A 1997 MOU between DOT and DOI established regulatory boundaries on the Outer Continental Shelf and contained a provision to coordinate research and development projects concerning Outer Continental Shelf pipelines. (5) OPS has participated in MMS sponsored research in the past in the area of welding research and is presently participating in research to assess the integrity of aging offshore pipelines and validating the performance of ILI tools ⁽¹⁰⁾. Another example of collaboration with a federal agency is a cooperative effort which is taking shape between OPS and the Department of Energy's National Energy Technology Lab (NETL) in Morgantown, WV. OPS has met with NETL personnel on a number of occasions to discuss common research issues. OPS has offered to participate in the selection of contractors in response to a solicitation NETL issued in October 2000 seeking proposals to provide research and technology development to maintain and enhance the integrity and reliability of the natural gas distribution and transmission systems across the United States. We are in the process of establishing cooperative arrangements with other federal and state agencies.

More public, industry, and governmental participation in setting agenda. OPS recognizes the need to work with other government agencies, the pipeline industry, and research organizations to pull together and optimize our research funding, solve common problems, and minimize duplication of effort. OPS is seeking outside advise in setting its research agenda for the future. OPS is in the initial stages of preparing to conduct a research planning conference. We believe such a conference is needed to bring the research needs of the pipeline industry into clearer focus, to establish a consensus on the adequacy of current research programs conducted by the government and industry, to ease concerns expressed by Congress and the public concerning the adequacy and reliability of existing technologies, and to establish a realistic research agenda for OPS and the industry. Federal and state agencies, pipeline operators, trade associations, research organizations and public interest groups would be invited to the conference. International organizations may also be invited. The goals of the conference would be to: (1) set the stage for a concerted and credible strategic approach to pipeline research planning; (2) provide a forum for broad-based input to planning; and (3) to develop strategies for leveraging scarce existing funds by joining federal and industry monies.

More shared funding. There appears that there will be more shared funding with other organizations both inside and outside the government. The present policy within OPS is to co-fund most, if not all, new research projects. An example of this is the next phase of the MFL mechanical damage research. The first phase conducted by the Battelle team was mentioned earlier. The next phase of the research is being conducted through a co-operative agreement with GRI approved in April 2000, which will be 50 percent funded by OPS.

The next phase of the mechanical damage research will examine the effectiveness of circumferential MFL. The use circumferential magnetic field is not new. Tuboscope used circumferential MFL in the 1970s to look for stress corrosion cracking and eventually abandoned the technique. With the introduction and gradual improvement of sensors and permanent magnets, circumferential MFL has enjoyed renewed interest in the 1990s. Trapil of France has been using a rotating circumferential MFL inspection system to find SCC in some 12-inch pipelines. Pipeline Integrity International has built circumferential MFL tools for a range of pipeline diameters (although they use the term transverse field MFL). (5)

Current MFL tools have inherent problems detecting, sorting, and sizing anomalies that are aligned with the tool's magnetization direction as well as resolving closely spaced pits. For example, a tool with an axially orientated magnetizing system has difficulty detecting defects that are axially aligned with little or no width in the circumferential direction. Similarly, a tool with a circumferentially orientated magnetizing system has difficulty detecting defects that are circumferentially aligned with little or no length in the axial direction. This is not a limitation of MFL technology; rather, it is a limitation of the magnetizer designs.

Many significant pipeline defects, including mechanical damage, corrosion and cracks, are axially long but circumferentially narrow. Flux leakage from long narrow defects is much lower in amplitude than those from short wide defects. To reliably detect, characterize, and determine the severity of such defects, better signals are required. One way to attain these better signals is to build a magnetizing system that provides a source field that is suitably oriented and strong enough to produce a leakage field that can be analyzed.

A circumferential magnetizer design may enable MFL to overcome many of the limitations associated with axial magnetizer designs. By itself, circumferential MFL has the potential to detect defects that axial MFL cannot by providing a field that is at right angles to the most significant defects. In combination with axial MFL, circumferential MFL should provide more accurate and reliable assessments of defect severity.

The current GRI/OPS program will combine the high and low magnetic field analysis technology used in the first phase of the research with circumferential MFL. Battelle, along with the Southwest Research Institute, will conduct the research for GRI/OPS. Battelle will study high and low field circumferential MFL for better characterization of long axially oriented mechanical damage defects. As Battelle investigates circumferential MFL fields, they will also look at other anomalies, such as metal loss from corrosion and stress corrosion cracking, because these anomalies exist in the PSF defect sets. Circumferential MFL should do a better job of sizing long narrow axial defects such as seam corrosion and may even help with the identification of SCC or longitudinal gouges in dents. It is not known whether circumferential MFL will do a better job at sizing corrosion, or whether it will need to be combined with conventional axial MFL signals for an improved inspection.

A circumferential magnetizer has been built to work with the MFL Test Bed Vehicle at the PSF. The magnetizer uses four poles to magnetize the pipe. Typically, because the magnets and brushes cover a substantial portion of the circumference, a second magnetizer is needed to attain a complete inspection. However, the defects in the pipeline simulation facility are in rows and repeated pulls will be can be used to acquire data from all of defects.

The magnetizer system allows the magnetization levels to be changed by addition or subtraction of individual magnets and shunts. The sensor system is based on the modular design of the test bed vehicle, which uses Hall-effect sensors. The sensors are spaced in 0.2-inch (5mm) increments in the circumferential direction. The sensors will cover about one-quarter of the circumference. The circumferential magnetizer and sensor system interfaces with the battery and data acquisition module of the MFL test bed vehicle.

Data will be collected from representative mechanical damage and metal loss defects so that the basic capabilities and limitations of circumferential MFL can be measured and compensation functions developed. Key issues will be addressed, such as the variations in magnetic fields between the magnet poles and differences between circumferential and axial MFL signals.

To assess the capabilities and limitations of circumferential MFL, a quantitative sizing comparison with axial MFL will be developed. Rather than developing specific sizing algorithms for circumferential MFL, the capabilities of circumferential MFL will be assessed by determining the statistical correlation between signal features and defect parameters for various types and sizes of defects. In this manner, the results will not be biased to any one analysis methodology. In addition, the results will identify which parameters are most likely to improve sizing accuracies if included in analysis packages.

To accomplish this objective, Battelle will collect MFL signals from metal-loss and mechanical-damage defects under a range of test conditions. The effects of velocity, magnetization level, and remnant magnetization will be examined using multiple runs in the pull rig. The flux leakage from various defects will be analyzed and, based on the fundamental principles of MFL technology, select signal features that are reliable, easily identifiable, and related to defect parameters or severity. Automated processes will be developed for extracting the signal features from the large number of inspection signals recorded.

The first data collection session is expected to take place in the first quarter of 2001, with data analysis and additional defect fabrication during the first and second quarter of 2001. This session will examine metal loss and mechanical damage defects under controlled conditions. Inspection variables, cracks and new defects will be examined in a second data collection session, which is scheduled for the third quarter of 2001.

Increased funding for research. It appears Congress will take a more active role and that OPS will have additional research funding. The proposed Senate Pipeline Safety Reauthorization Bill, S. 2438, introduced in the last session of Congress, sent a strong message, as a result of the Bellingham failure, that pipeline safety research is important by proposing to increase pipeline safety research funding to $4.0 million and directing OPS to enter an arrangement with the National Academy of Sciences to establish and manage a Pipeline Integrity Technology Advisory Committee. This Committee would advise OPS and the Department of Energy (DOE) on the development and implementation of a 5-year research, development, and demonstration program plan.

The bill passed the Senate, but did not pass the House of Representative during the 1999-2000 session of Congress. Even though it didn't pass, it shows the intent of Congress to increase its support of pipeline research. We look forward to it being re-introduced during the 2001-2002 session of Congress.

Research into new technologies. There also appears that more research into new technologies will be undertaken. In the past most OPS research was tied to regulatory activities or aimed to solve a particular safety problem. The proposed Senate Pipeline Safety Reauthorization Bill, S. 2438, also contained a provision requiring OPS to support innovative technology development for pipelines that can't accommodate ILI tools.

References

• Paul Biancardi, "An Introduction to Federal Pipeline Safety Regulations," presented at the Institute on "Oil and Natural Gas Pipelines: Wellhead to Enduser," Denver, Colorado,1995.

• Annual Report on Pipeline Safety, Calendar Year 1986.

• U.S. Department of Transportation, "Instrumented Internal Inspection Devices, (A Study Mandated by P.L. 100-561)," November 1992.

• Annual Report on Pipeline Safety, Calendar Year 1993

• GRI, "Technical Proposal, Better understanding of Mechanical Damage in Pipelines," March 2000.







APPENDIX A

 

 Completed Research Activities in OPS, 1970-2000

YEAR(1) 1970	CONTRACTOR(2) Automatic Systems Corp.	DESCRIPTION Develop a data system to process failure reports	RESULTS(2) Initial aspects of research became operational in 1971
1970	Southern Cross Corp.	Conduct leak surveys on 20 municipally-owned gas systems using flame ionization techniques	Condition of these systems comparable to other gas distribution systems
1970	IITRI	Develop information for preparing accident investigation and state monitoring manuals	Not readily available
1970	Tracor	Investigate state-of-the-art in gas sealing materials and techniques	Promising techniques were identified
1971	Mechanics Research, Inc.	Determine the state-of-the-art of corrosion on steel pipe	Compendium on corrosion analysis and literature abstracts with overall evaluation of the problem were reported
1971	National Bureau of Standards	Provide inspection, testing, and metallurgical services on failed pipe and components	NBS utilized in  investigations from 1972 through 1980
1973	Mechanics Research, Inc.	Evaluate the stress design criteria of the proposed Trans-Alaska crude oil pipeline	Stress design criteria was found to be adequate
1974	Mechanics Research, Inc.	Develop background information on the rapid shutdown (RS) of failed gas and liquid pipelines and limiting excess pressure on pipelines to prevent failure	RS does not reduce accident effects, and cost of implementing RS is 1 to 2 orders of magnitude greater than benefits
1974	University of Oklahoma	Develop automated leak and failure reporting system	Recommendation made  to improve the validity, reliability, and usability of data produced by the current system
1974	Arthur D. Little, Inc.	Study the technology and current safety practices for transporting and storing LNG	Consideration of materials, design, construction practices, and an approach to assessing risks were reported
1975(3)	Toups Engineering, Inc.	Study pipeline industry’s practices in using plastic materials in gas pipelines and the resulting safety factors	Not readily available
1975(3)	Institute of Gas Technology	Study the properties of odorants and assess their effectiveness to alert people of a leak	Not readily available
1975(3)	AMF’s Advanced Systems Laboratory	Evaluate the tools and procedures for assessing the safety of gas distribution systems including technology and equipment available for in-place evaluations of the systems	Not readily available
1975(3)	AMF’s Advanced Systems Laboratory	Study current practices, technologies, problems and recommendations relating to the overall safety of gas distribution systems	Not readily available
1976	Arthur D. Little, Inc., Cambridge, MA	Develop basics criteria for safety from thermal radiation and for dispersion of flammable clouds resulting from LNG spills.	Not readily available
1976(3)	AMF’s Advanced Systems Laboratory	This summary evaluation used the studies on plastics, odorization, and tools and procedures for assessing the safety of gas distribution as well as the study of current practices in the gas distribution industry	Not readily available
1977	U. of OK, Office of Research Administration, Norman, OK	Review and prepare suggested revisions to the OPS gas leak and annual report forms	Suggested revisions were incorporated in revised forms to reduce the burden on the pipeline operator
1977	National Bureau of Standards	Study the design and construction of the aboveground support system (VSM) on TAPS to determine compliance with 49 CFR part 195	The study provided an independent review of the adequacy of the VSM system, which was found adequate
1977	National Bureau of Standards	Assisted in determining the acceptability of certain welds on the Trans-Alaska crude oil pipeline (TAPS)	Used fracture mechanics as an alternate standard to 49 CFR part 195 for justification of a waiver for 612 girth welds on TAPS
1978	Advanced Systems Laboratory Engineering, Inc., Goleta, CA	Study on the problems of hydrogen stress cracking, hydrogen embrittlement, stress corrosion cracking, and corrosion fatigue to appraise OPS of the seriousness of these problems and recommend remedial actions to pipeline operators	Not readily available
1978	Drovo Van Houten, Inc., New York, NY	Study the practices to assure the safe operation of gas and liquid offshore pipelines	Report included recommendations for regulation revisions, future research and other actions to improve the safety of offshore pipelines
1978	IIT Research Institute, Chicago, IL	Evaluate the effectiveness of programs for the prevention of damage to pipelines by outside forces	Report included recommendations for regulation revisions, future research and other actions to reduce outside force damage
1978	Not readily available	A Study assessing the problems associated with installation and maintenance of pipelines in Arctic waters, conducted in cooperation with the US Geological Survey, DOI	Results used to formulate possible future regulations
1979	National Fire Protection Association (NFPA)	Develop a course to train emergency response personnel to deal with pipeline emergencies. This in response to NTSB after 35 firemen were injured in a six month period responding to two natural gas pipeline emergencies	A 51/2 hour audio-visual training course was developed
1979	Systems & Applied Sciences Corporation (SASC), Riverdale, MD	Study to determine the number of master meter systems in the US to determine if any problems exist with their operation and maintenance	The number, and location were identified.  One outcome: Regulations will be tailored to such systems
1981	Harco Corporation	Study to verify and document methods of complying with the regulations for monitoring external corrosion in urban areas with issues like wall-to-wall pavement	Completed in 1981.  Results of study used in a regulatory review of the pertinent requirements in 49 CFR part 192
1981	Woodward-Clyde Consultants	Study the unique safety problems in the design, construction, maintenance, and operation of Arctic pipelines	Not readily available
1983	National Bureau of Standards	Develop procedures for the use of fracture mechanics as an alternate method of assessing the acceptability of defects in pipeline girth weld	Completed in 1983 and formed the basis for the fracture mechanics appendix in API Standard 1104
1983	Not readily available	Develop guidelines for the design of trench profile to minimize the dangers of pipe rupture during lowering operations	Not readily available
1983	Not readily available	Develop procedures and equipment capable of detecting bacterial corrosion and establish mitigation criteria	Not readily available
1983	Gas Research Institute	Based on initial field trials, OPS sponsored a further set of field trials, wind tunnel simulation tests, and development of a predictive technique for vapor dispersion	Objective was to establish an alternate vapor dispersion standard and thereby reduce the size of  vapor exclusion zones in the LNG regulations. The first phase of tests completed in 1984.  A total of six phases were conducted in the project, some phases co-sponsored with the Gas Research Institute (GRI) and others sponsored by GRI alone.  The final report in Feb. 1991 was challenged by experts in the field, but all agreed any current dispersion models are reasonably conservative for use in Part 1
1983	Not readily available	Co-sponsored, with the US Coast Guard and an international consortium, research to learn the effect of obstacles on dispersion of LNG vapor	Initial trials were completed in 1983
1984	Not readily available	Assimilate technical data through literature search and worldwide survey on manufacturing capacities, specification of supplemental requirements, and weld repair technologies for Arctic line pipe	Findings will be used for future rulemaking on pipe requirements in Arctic applications
1984	Wyle Laboratories	Study the safety criteria for the operation of gaseous hydrogen pipelines	Under certain circumstances, gaseous hydrogen could pose risks that are not adequately addressed in 49 CFR part 192
1985	Volpe National Transportation Systems Center, DOT	Study the safe transportation of methanol by pipeline	Report concluded there appears to be no serious technical impediments to the transportation of methanol by pipeline
1985	Not readily available	Study the potential for sulfide stress corrosion cracking from transportation of extremely toxic hydrogen sulfide, H2S, and establish inspection strategies for pipelines transporting H2S	Concern with weld cracks in pipe with elevated temperatures located immediately downstream from compressor stations
1985	Not readily available	Study the aging mechanisms of cast iron pipe to determine what conditions lead to graphitization including methods of determining graphitization and testing for residual strength	Not readily available
1986	Volpe National Transportation Systems Center, DOT	Examine unregulated storage to determine if the record in terms of accidental releases reportable under 49 CFR part 195 is better or worst than that of regulated storage (breakout tanks)	The study found that the historical accident rate per tank for unregulated storage was not higher than for breakout tanks so that regulation of unregulated storage would not significantly contribute to pipeline safety
1987	Southwest Research Institute	Cooperative research with the AGA into the relevancy of pipe yield/tensile (Y/T) ratio as a suitable measure of static and dynamic fracture toughness	Study concluded a high Y/T ratio (> 0.95) had no adverse effect on the ductility or resistance to rapid crack propagation.  Drop weight tear testing, combined with dynamic visco plastic finite element analysis offer promise to characterize rapid crack extension of ductile pipeline steels
1987	Volpe National Transportation Systems Center, DOT	Examine the problem of outside force damage to natural gas pipelines and the efforts to control it	The study found that the degree of participation in a one-call system and knowledge of it through advertising reduced incidents; performance in municipal and private owned systems did not differ; presence of a state damage prevention law affects incident level, however state requirements that operators respond to all excavation notices and participate in one-call systems do not
1989	Arthur D. Little	Combination of high stress levels and significant levels of hydrogen sulfide in a pipeline can result in sulfide stress cracking (SSC).  Study to determine threshold stress that may result in SSC	Concluded that for API 5L-X65 pipe, structural integrity of pipe not compromised at a hydrogen sulfide level of 100 ppm and a maximum yield stress of 70 %
1990	Volpe National Transportation Systems Center, DOT	Study the feasibility of regulating persons whose excavation activities may result in damage to pipelines.  (Required by the Pipeline Safety Reauthorizaton Act of 1988)	Study found not feasibile because excavation-related safety has improved dramatically; existing rules effectively facilitate advance notification; limited impact on pipeline safety; and, would duplicate OSHA rules.
1994	Marine Board of the National Research Council	Study the safety of marine pipelines after a number of accidents occurred in the late 1980's	The final report recommended clarifying the jurisdictional division between RSPA and the Mineral Mining Service (DOI); developing a common safety database; and determining that safety regulations be based on sound risk and cost-benefit analysis
1995	Volpe National Transportation Systems Center, DOT	Investigate and analyze the various Supervisory Control and Data Acquisition (SCADA) methods for use to detect pipeline leaks including leak detection systems (LDSs)	Study found companies have made major investments in SCADA systems, less in LDSs; a reliable sysem with a low false alarm rate is crucial; the dispatcher is the critical link in any system
1996	LRL Sciences, Inc, Albuquerque, NM	Study to provide information with respect to the problem and the need for regulation of underground storage caverns	Report described the results of surveying 10 % of the industry, with 61% under some form of federal regulation and 85% under state regulation.  Pros and cons of regulating underground storage facilities were presented.
1996	New Jersey Institute of Technology	Study analyzed the maintenance and rehabilitation practices of the pipeline industry, compared them with the pipeline safety regulations, and compared U.S. with foreign regulations as they relate specifically to land use and siting	The study found that, of the operators surveyed, the federal requirements in testing and welding requirements were exceeded, construction requirement were equaled, and the best preventive maintenance measure was quality control during construction. Siting and land use requirements in Canada, Australia, Germany, Japan, and the UK were similar to the U.S. however some included the concept of pipeline life, fatigue life, 3rd party factors, use of in-line instrumented pigs, and earthquake impacts not found in U.S. regulations
1996	New Jersey Institute of Technology	The research developed a failure consequence database based on failure reports from the National Transportation Safety Board	The damage area found in the database was used with a sample Geographic Information System (GIS) to determine the damages that would result if a failure occurred at locations along the simulated pipeline in the GIS
1996	New Jersey Institute of Technology	The research identified the factors that cause pipeline failures on hazardous liquid pipelines	The main finding was that better and more complete failure data is needed to be collected
1996	New Jersey Institute of Technology	The research identified the factors that cause pipeline failures on natural gas pipelines	The main finding was that better and more complete failure data is needed to be collected
1997	Texas Transportation Institute, Texas A & M University	Study to analyze the risks and consequences of pipelines being seriously affected by natural disasters and propose potential mitigation measures for these pipelines to prevent leaks or spills	Five areas were identified to contain significant pipeline systems that are threatened by natural disasters and 16 mitigating measures were presented
1997	Texas Transportation Institute, Texas A & M University	Research including experimental testing and finite element analysis to better understand the behavior of dents in pipelines	The study reported a method to estimate original dent depth if rebound depth is measured, documented fatigue cracking behavior in both restrained and unrestrained dents, and reported acceptance criteria parameters as dent type, dent depth, pressure history, restraint conditions, and pipe parameters
1997	Texas Transportation Institute, Texas A & M University	Research to develop procedures to apply fracture mechanic concepts, in particular leak-before-rupture to hazardous liquid and gas pipelines	The study found fracture propagation in gas pipelines  reduced with increasing class location (unlikely in Class 4, likely in Class1) and reduced pipe diameter-to- wall-thickness ratio.  Fracture mechanics was used to predict rupture formation  from hazardous liquid pipelines with the indication that the leak from a stable crack prior to formation of an unstable crack will possibly provide for detection before rupture occurs
1997	Texas Transportation Institute, Texas A & M University	Study to develop design, construction and maintenance recommendations for breakout tanks	10 API publications and one NFPA Code was recommended for adoption in the DOT liquid pipeline safety regulations
1997	General Physics Corporation	Study of the various rehabilitation methods used in gas distribution piping systems and evaluate their efficacy	Pipe liner systems, trenchless methods, and joint sealants were studied and compared
1997	Federal Emergency Management Agency Mitigation Directorate	Conduct a study using a Geographic Information System (GIS) into design, construction and operation methods that operators use to counter the effects of natural disasters  as a result of pipeline failures due to natural disasters, e.g., San Jacinto floods in Texas	A prototype study in the San Jacinto river basin was conducted (1995) to refine the methodology used for analysis; an assessment of risks to pipelines from natural disasters was performed (1996); an assessment of consequences in the event of pipeline failure was performed (1996); pipeline segments in high-hazard, high-consequence areas were identified (1996); and, a summary report presenting the computer programs and methodology for evaluating pipeline risk and consequence from natural disasters was produced (1997)
1998	Texas Transportation Institute, Texas A & M University	Study to determine the need for inspections of pipeline burial depth in the Gulf of Mexico for DOT  regulated pipelines	Study found current survey techniques are effective and periodic inspection is needed to assure adequate burial depth as at least 2 % of the pipelines surveyed had inadequate cover
1998	Battelle/Southwest Research Institute	Study of the magnetic, mechanical, chemical, and metallurgical properties of 36 pipeline materials removed from gas transmission service	Result of study showed there is no clear correlation between magnetic properties and commonly measured mechanical properties
1999	General Physics Corporation	Study to assess and evaluate existing techniques and methods to determine the remaining safe strength (before yield is exceeded) in a buried steel pipeline which has been subjected to earth movement	Of the nine methods evaluated, only strain gages provide a continuous real time stress measurement
1999	General Physics Corporation	Study to collect and consolidate stress corrosion cracking (SCC) data available on U.S. and Canadian gas pipelines and document detection and mitigation methods	Study concluded SCC failure is almost as likely to occur on a gas pipeline within the U.S. as in Canada, based on data from the Interstate Natural Gas Association of America (INGAA) and the Canadian Energy Pipeline Association (CEPA).  Study recommended continued review of SCC incidents by OPS, revising failure forms to identify SCC, and continue to collaborate with INGAA on managing SCC on gas pipelines
1999	Battelle	Study for the Gas Pipeline Safety Research Committee of the ASME to establish a field practice for nondestructively evaluating in-service pipe of unknown tensile properties to determine its tensile properties, using hardness measurements	The statistical procedures   developed in this study maintain the degree of uncertainty evidenced by current testing requirements
2000	General Physics Corporation	Study responding to the National Transportation Safety Board (NTSB) recommendation to determine the extent of the susceptibility to premature brittle-like cracking of older plastic pipe in gas service	Study concluded more extensive installation, operation, and failure data needs to be gathered by the industry and OPS in order to monitor the safety of plastic pipe
2000	Battelle/Southwest Research Institute/ Iowa State University	Study evaluated and developed inspection technologies for mechanical damage and stress corrosion cracks in pipelines	The use of magnetic flux leakage (MFL) technology on in-line inspection equipment for detecting and characterizing mechanical damage to pipelines was advanced for use in commercial application

 

______________________________________________________________________

(1)            The year the study was completed or a report issued.

(2)            Much of the research activity was obtained from the annual reports to congress, required by statute, on the administration of the Natural Gas Pipeline Safety Act of 1968. In some instances, the contractor conducting the study and/or the results were not documented in the annual report.

(3)            Performed under a special allocation by Congress to study the safety of distribution systems as reported in the 1974 annual report to Congress on the administration of the Natural Gas Pipeline Safety Act of 1968..

CONTRACTOR: Battelle, Southwest Research Institute, and Iowa State University

FUNDING: $3,058,093

DOT sponsored a 40 month research contract to advance the in-line inspection (ILI) technology of magnetic flux leakage (MFL) to detect and characterize mechanical damage. The contract, which commenced in June 1996, conducted research with orientation of the magnetic field in the conventional direction along the longitudinal axis of the pipe. An addition two year, contract co-funded with the Gas Technology Institute (GTI) ⁽¹¹⁾, will complete the full range of testing to identify and characterize mechanical damage by conducting testing with the magnetic field in the pipe's circumferential direction (see below).

The work focused on determining the severity of defects and the likelihood of them threatening the integrity of a pipeline. This was accomplished by producing a number of defect sets and testing them in a 300-foot pull rig and the 4700-foot flow loop under realistic pipeline conditions at GTI's Pipeline Simulation Facility, a world-class ILI testing facility located near Columbus, Ohio. Flow loop tests were conducted to determine the effects of stress and pressure on mechanical damage signals and calibrate the prior results taken under unpressurized conditions in the pull rig. The results have been analyzed and techniques have been developed to measure stress and determine the severity of mechanical damage. A prototype ILI tool is being constructed by a domestic ILI vendor using the results from this research.

TITLE: Pipeline Detection Research and Development

CONTRACTOR: North Carolina State University's Construction Automation & Robotics Laboratory (CARL)

FUNDING: $10,000

Outside force damage is the leading cause of pipeline failures. Over the past 10 years, nearly 75% of fatalities and injuries from gas distribution incidents and over 60% of failures are attributable to outside force damage. CARL is developing mountable utility location technologies that warn the machine operators of existing underground facilities before damage occurs. The developed prototype system, known as Buried Utility Detection System (BUDS), is capable of locating metallic pipes underground, according to feedback from users. The present contract would develop and test a "stop-light" feature added to BUDS. This feature would be similar to a traffic light in that green would mean continue digging safely; yellow would mean a utility is nearby; and red would mean a utility is directly in subsurface area and digging must stop; thereby preventing damage to the underground utility.

TITLE: Better Understanding of Mechanical Damage in Pipelines

CONTRACTOR: Gas Technology Institute (Battelle)

FUNDING: $2,000,000 ⁽¹²⁾

This is a two year research program with GTI which commenced in April 2000 to investigate MFL oriented in the circumferential direction on an ILI tool. The tool will identify and characterize pipeline mechanical damage, the leading cause of reportable accidents in both gas and hazardous liquid pipelines.

This research is a cooperative effort under the MOU between GRI and the Department signed on June 20, 1996 formalizing a partnership to further our mutual interests in providing public safety, environmental protection, and reducing risks from gas transmission and hazardous liquid pipelines.

This research will complement a 40 month DOT sponsored research program conducted by Battelle along with Southwest Research Institute (SwRI) and Iowa State University. That research involved MFL oriented in the more traditional axial direction on an ILI tool. The present research would allow for evaluating the most severe mechanical damage which is damage oriented in the axial direction.

TITLE: Performance of Offshore Pipelines (POP), a Joint Industry Project (JIP)

CONTRACTOR: WINMAR Consulting Services, Inc.

FUNDING: $50,000 ⁽¹³⁾

RSPA is sharing in the funding of the first year of this $1,000,000 two year project which commenced in May, 2000. This research and development project will assess the integrity of aging offshore pipeline systems by testing and validating the performance of "smart pigs" as tools to determine pipeline conditions on a number of abandoned offshore pipelines, field testing the pipelines to failure, and then compare the failures with assessment models for predicting condition/failure. The models that will be validated through assessment with the failures include the ASME B31.G, R-Streng and DNV RP501 models for pipelines along with other models identified by JIP participants

TITLE: Airborne Ground-Penetrating Radar to Support Monitoring of Pipeline Safety and Performance ⁽¹⁴⁾

CONTRACTOR: AERIS, Inc.

FUNDING: $398,274 ⁽¹⁵⁾

This one year contract commenced in June 2000. Airborne-ground-penetrating radar has the potential to address key transportation requirements in infrastructure management and environmental assessment, including detection and mapping of buried pipelines and early detection of leaks. AERIS will optimize a radar configuration used for a NASA project and fly over simulated pipeline failures in Oklahoma to address pipeline and spill detection capabilities as a function of distance/slant range and angle of incident. The results of this project should be an applications-ready airborne system capable of substantially increasing efficiency and reducing costs and schedule for projects involving pipeline detection and mapping, monitoring and leak detection, and site investigation/assessment. In addition, AERIS will complete an analysis and assessment of the capabilities and benefits of hyperspectral imaging for supporting pipeline leak detection.

TITLE: Environmental Impact and Risk Modeling of Petroleum and Gas Transmission Lines using Interferometry and High Resolution Imagery from Satellite and Airborne-Based Remote Sensing Systems⁴

CONTRACTOR: EarthWatch, Inc.

FUNDING: $228,290 ⁽¹⁶⁾

This 18 month contract commencing in July 2000. Synthetic Aperture Radar Interferometry (InSAR) has the ability to detect and map centimeter scale deformation in petroleum and gas transmission line corridors on a system wide basis. High resolution optical satellite imagery coupled with InSAR offer the ability to accurately characterize environmental conditions and features for hazard and risk assessments. EarthWatch in this project will focus on developing processes and associated techniques to model, invert, and interpret high-resolution multispectral imagery (provided by Earthwatch Inc. from their QuickBird satellites) and InSAR data (as appropriately available) for petroleum and gas transmission corridor risk analysis including deformation in pipeline corridors.

TITLE: Real Time Monitoring of Contact to Pipelines ⁽¹⁷⁾

CONTRACTOR: Gas Technology Institute (Battelle)

FUNDING: $350,000 ⁽¹⁸⁾

Mechanical damage is the largest cause of reportable incidents in the DOT incident database. GRI studied these incidents through a contract with Dr. John Kiefner and found 32% of all incidents are caused by mechanical damage, and about 12% of these incidents (or 4% of the total incidents) were the result of a delayed failure. Although only a fraction of these incidents were preventable through monitoring, Dr. Kiefner found a disproportionate cost associated with delayed failures due to incidents with large consequences such as the Edison, NJ incident. This disproportionate cost of delayed failures is similar for liquid pipelines because of failures like the ones in Bellingham, WA and Reston, VA.

For the past five years GRI (now GTI) has been studying detection of backhoe hits and other contact with pipelines through work performed at Battelle. GTI has learned that contact with the pipe generates low frequency acoustic waves in the gas stream that can travel for miles. This signal can be detected by attaching low frequency accelerometers or geophones to the outside of the pipe. Experiments have determined how far these signals will travel, how they can be detected in the presence of typical pipeline noise sources, what are the characteristics of backhoe hits versus scrapes, and gouges, and most recently how does the system perform on an actual pipeline.

One phase of this five year effort consists of a demonstration and two year field experiments on two separate operating pipelines to examine the long term effects of actual field use of the system. The present proposal covers the completion of this phase, and a guided boring study at GTI's Pipeline Simulation Facility (PSF) near Columbus, Ohio. A paper published by the Japanese reported that acoustic signals generated from guided boring machines are significantly smaller than those generated from backhoe contact to the pipeline. An experiment to verify these results will be carried out.

GTI will fund an experiment in the 4700-foot flow loop at the PSF to determine acoustic signal levels from guided boring contact. In addition to testing acoustic methods developed by GRI over the past five years, PRCI will test the sensitivity of a cathodic protection (CP) monitoring system. Real Time CP monitoring is a method PRCI has pursued during the last 2 years with cofunding from GRI. If acoustic methods do produce small signals as the Japanese have reported, it is envisioned that CP monitoring will complement acoustic monitoring and improve monitoring for these situations.

_______________________________________________________________________

1. The five OPS regions are headquartered in Washington, DC (Eastern Region), Atlanta, GA (Southern Region), Kansas City, KS (Central Region), Houston, TX (Southwest Region), and Denver, CO (Western Region).

2. Title VII, Subtitle C- Comprehensive One-Call Notification, included in The Transportation Equity Act for the 21^st Century (TEA-21).

3. 65 FR 75378; December 1, 2000.

4. The 1979 amendments to the NGPSA included the HLPSA, an entirely new statute which mirrored the authority contained in the NGPSA and brought the safe transportation of hazardous liquids under the OPS.

5. This number designates the reference number from the last section of this paper.

6. GRI is referenced throughout this paper for convenience. However, GRI and the Institute of Gas Technology located in DesPaines, Illinois, near Chicago, combined in April 2000 to form the Gas Technology Institute (GTI).

7. The nonlinear harmonic method is an electro-magnetic technique that is sensitive to the state of applied stress and plastic deformation in steel. A sinusoidal magnetic field is applied at a fixed frequency. Odd-numbered harmonics of that frequency (typically the third harmonic) are generated because of the non-linear magnetic

characteristics (hysteresis curve) of ferromagnetic materials. By detecting and measuring the harmonic signal, changes in magnetic properties can be inferred.

8. A neural network analysis method uses a large number of relatively simple calculations to make a prediction. As an example, a neural network might be designed to predict the shape of a corrosion defect or classify a possible defect based on information contained in the MFL signal. Although the calculations are simple, the large number of computations allows neural networks to perform sophisticated tasks.

9. Most of the effort in this research was focused on MFL and its application to ILI tools. However, the Battelle team also investigated two electromagnetic technologies to identify and characterize stress corrosion cracking (SSC) that can be used in conjunction with, or as a modification to MFL ILI tools. There have been several unsuccessful attempts in the past to develop SCC pigs utilizing ultrasonic technology, but little has been done to advance electromagnetic technology. Failures due to SCC occur less frequently than mechanical damage, but have resulted in catastrophic failures when they do occur.

10. Current OPS research projects are listed in Appendix B.

11. Formally the Gas Research Institute (GRI).

12. Co-funded, 50 % by GRI and 50 % by RSPA over two years.

13. Funding provided to the Minerals Management Service, Department of the Interior through a Reimbursable Agreement.

14. This project is being funded under Section 5113 of Public Law 105-178, the Transportation Equity Act for the 21^st Century (TEA-21), enacted on June 9, 1998, authorizing the Secretary of Transportation to carry out a Commercial Remote Sensing Products and Spatial Information Technologies Program in cooperation with NASA. The program is designed to validate commercial remote sensing products and spatial information technologies for application to national transportation infrastructures development and construction.

15. Project is cost-shared: $212,654 is DOT share, $185,620 is AERIS share.

16. Project is cost-shared: $198,440 is DOT share, $29,850 is EarthWatch share

17. A cooperative agreement with GTI for this project is pending.

18. 50 % co-funded by GTI and 50% by DOT.