Pipeline Compliance and Risk Management Pipeline Risk Assessment Line 9B Reversal and Line 9 Capacity Expansion Project

Transcription

1 Page of Pipeline Compliance and Risk Management Pipeline Risk Assessment Line B Reversal and Line Capacity Expansion Project

2 Page of TABLE OF CONTENTS.0 EXECUTIVE SUMMARY....0 INTRODUCTION....0 PIPELINE RISK ASSESSMENT MODEL.... HIGH CONSEQUENCE AREAS.... UNKNOWN OR MISSING DATA.... FACTORS AND VARIABLES....0 GENERATION OF RISK ASSESSMENT RESULTS....0 SUMMARY... APPENDIX I - PIPELINE RISK ASSESSMENT MODEL... APPENDIX II - RISK ASSESSMENT RESULTS....0 CURRENT LINE CONFIGURATION RISK ASSESSMENT RESULTS....0 LINE B REVERSAL RISK ASSESSMENT METRE RISK ASSESSMENT SECTIONS....0 RISK PROFILES....0 IDENTIFICATION OF RISK MITIGATION ACTIVITIES....0 LINE B REVERSAL.... LIKELIHOOD COMPARISON RESULTS.... CONSEQUENCE COMPARISON RESULTS.... RISK COMPARISON....0 LINE CAPACITY EXPANSION.... CONSEQUENCE COMPARISON RESULTS.... RISK COMPARISON...

3 Page of GLOSSARY OF TERMS DOT HCA Line B Line B Reversal and Line Capacity Expansion Project U.S. Department of Transportation High Consequence Area -kilometre segment of Line from rth Westover Station to Montreal Terminal Proposal to reverse a section of Line between rth Westover and Montreal and concurrently expand the overall annual capacity of Line from Sarnia to Montreal m cubic metre Project Line B Reversal and Line Capacity Expansion Project

4 Page of EXECUTIVE SUMMARY The Operational Risk Management Pipeline Risk Assessment Model integrates the results of the corrosion, cracking, and mechanical damage analyses contained in the Pipeline Integrity Management Plan with (a) other potential pipeline threats (including third party damage, ground movement, natural forces, incorrect operations and appurtenances) and (b) the potential consequences of these pipeline threats (including impacts on population, environment, and business). The integration of this data yields a relative comparison of the risk for the pipeline (using 00 meter segmentation). These results are reviewed annually to determine the need for mitigation activities in addition to those that are already in place for individual threats driving the identified risks. The model is relative in that the risk score for one section of pipeline can be compared to the risk score for another pipe section, but the risk scores have no meaning outside of the risk model. The risk assessment results for the Line B Reversal portion of the Line B Reversal and Line Capacity Expansion Project (the Project ) demonstrate minor changes in the likelihood of failure. Susceptibility of the pipeline to external and internal corrosion remains unchanged with the reversal. The susceptibility to cracking potentially increases for those sections of pipe now at the discharge side of the pump and decreases for those sections that are now at the suction side of the pump. Natural forces, system operations, appurtenances, third party and ground movement threats do not change with the proposed reversal. Risk control and mitigation for external corrosion, internal corrosion, cracking, and mechanical damage are discussed in the Pipeline Engineering Assessment. Consequence of failure is not dependent on flow direction and no change in consequence is expected from the Line B Reversal. The increase in Line capacity as a result of the Line Capacity Expansion portion of the Project results in a minor increase in assessed risk for 0.% of the pipeline. In summary, the reversal of Line B will result in minor increases of risk to the operation of the pipeline at the discharge side of the pump stations (rth Westover, Hilton, Cardinal and Terrebonne) and in minor decreases of risk to the operation of the pipeline at the suction side of the pump stations (Hilton, Cardinal, Terrebonne and Montreal). The increase in capacity to Line as a whole yields a minor increase in risk for 0.% of the pipeline. Overall, the changes in risk results as a result of the Project are minimal, and the risk control and mitigation strategies currently being executed by Enbridge manage these risks.

5 Page of 0.0 INTRODUCTION The Enbridge Operational Risk Management Pipeline Risk Assessment Model comprehensively evaluates the range of threats (corrosion, rock cracking, denting, third party damage, natural forces, ground movement, appurtenances, and system operations) and consequences (impact on population, environment and customers) to the pipeline system. The model is relative in that the score for one section of pipeline is compared to that of another section; the score in and of itself has no meaning. The Pipeline Risk Assessment Model development was initiated at Enbridge in Since that time the model has undergone annual refinement to ensure that it meets changing business and regulatory requirements. A high-level overview of the Pipeline Risk Assessment Model is provided in Figure. The model includes those likelihood and consequence conditions applicable to Enbridge liquids pipelines. Relative Risk Value = Likelihood X Consequence External Corrosion Likelihood Factors: Internal Corrosion Cracking Consequence Factors: Impact on Population Rock Denting System Operations Third Party Damage Impact on Environment Natural Forces Ground Movement Appurtenances Impact on Customers Figure The Enbridge Liquid Pipeline Risk Assessment Model The Pipeline Risk Assessment Model was developed by a working group of subject-matter experts from Enbridge s Pipeline Integrity, Environment, Operations, and Operational Risk Management departments. This Working Group meets as required to initiate, review, and approve changes or refinements to the Pipeline Risk Assessment Model.

6 Page of The Operational Risk Management Pipeline Risk Assessment program includes Line B in its current configuration from Montreal to rth Westover. Once the Line B reversal is completed, Operational Risk Management will make the appropriate changes to data contained within the Pipeline Risk Assessment Model and generate new risk assessment results PIPELINE RISK ASSESSMENT MODEL. HIGH CONSEQUENCE AREAS The term High Consequence Area ( HCA ) is derived from the U.S. Department of Transport ( DOT ) Code of Federal Regulations.0. HCAs are sensitive areas in close proximity to a pipeline that in the event of a pipeline rupture have a high probability of being impacted. Enbridge identifies five types of HCA.. Highly Populated Area;. Other Populated Area;. Drinking Water Resource;. Environmentally Sensitive Areas; and. Commercially Navigable Waterways. A pipeline that traverses a HCA is considered to have a direct impact because any volume of product released will impact the HCA. In the event that an HCA is some distance from the pipeline but can still be impacted through a transport mechanism (spray, overland flow, water transport, air dispersion), the pipeline section in question is said to have a transport impact on the HCA. To collect information about HCAs in Canada, Operational Risk Management first used information available in Canada (e.g. Species at Risk legislation, population survey data), and then used U.S. DOT definitions to guide population, drinking water, environmental, and commercially navigable waterway data collection and compilation from various municipal, provincial, and federal agencies.. UNKNOWN OR MISSING DATA The Enbridge Pipeline Risk Assessment Model considers all unknowns as worst case; thus variables that are unknown are assigned the highest score. Unknowns result from data that is missing or that does not exist.

7 Page of 0. FACTORS AND VARIABLES A review of the likelihood and consequence factors or categories and their associated variables for the pipeline risk assessment is provided in Appendix I. The Project includes the reversal of Line B to flow from rth Westover to Montreal and flow rate increase on Line of up to, m /day. The majority of variables in the Pipeline Risk Assessment Model are not affected by these proposed changes. The Pipeline Risk Assessment variables that are affected by the Line B flow reversal or the increase in Line capacity are identified in Table. Table - Variables Impacted by the Reversal of Line B and/or Capacity Increase Applicable Portion of the Project Factor Variable Effect on Risk Assessment Results Line B Reversal Cracking Distance Downstream from Station Line Capacity Expansion Line Capacity Expansion Impact on Population Impact on Environment Impact on Population Impact on Environment Initial Volume Loss - Rupture Transport HCA effect in the short term; the population of susceptible features will not vary. In the long term, potential growth will be driven by proximity of station discharge (features seeing a higher pressure ratio delta will have more driving force to grow by fatigue). The initial volume out is the amount of product released at design flow rate before remote controlled valves are closed and the pipeline isolated. The increase in initial volume out with the Project is approximately m. This change yields a minor increase in assessed risk for 0.% of Line. The change in product flow rate yields an increase of initial volume out of m. This increase of volume out has minimal impact on modeled transport impacts to HCAs. As noted in Table, there are three variables in the Risk Assessment Model that have the potential to change with the proposed reversal and increase in capacity. An overview of the change in risk assessment results as a result of the proposed Line B reversal and Line capacity expansion is provided in Appendix II.

8 Page of 0 0 Data used in the Pipeline Risk Assessment is reviewed and updated annually..0 GENERATION OF RISK ASSESSMENT RESULTS Risk assessment results are generated by Operational Risk Management and include a summation of the likelihood and consequence scores for each section of pipe being evaluated. The assessment typically uses a risk assessment section of 0 m (000 ft). This assessment section length was selected and approved by the Pipeline Risk Assessment Model Working Group. The risk assessment results generated for the Pipeline Risk Assessment Model aid in decision-making in the following areas. Identification of risk management projects. The risk assessment results enable an understanding of the risk drivers so that an optimum combination of risk management activities can be identified, pursued, and implemented. Prioritization of projects / optimization of expenditures. The risk assessment results support the prioritization or optimization of expenditures for those areas with the highest risk ranking. Operational Risk Management annually distributes risk assessment results to all Enbridge Regions and the Pipeline Integrity department, and facilitates discussion of possible risk management projects and activities..0 SUMMARY In summary, the Line B reversal portion of the Project will result in minor increases of risk to the operation of the pipeline at the discharge side of the pump stations (rth Westover, Hilton, Cardinal and Terrebonne). The reversal of Line B will result in minor decreases of risk to the operation of the pipeline at the suction side of the pump stations (Hilton, Cardinal, Terrebonne and Montreal). An increase in risk will be realized for approximately 0. % of Line as a result of the proposed capacity expansion portion of the Project. Overall the changes in risk results as a result of the Project are minimal, and the risk control and mitigation strategies currently being executed by Enbridge manage these risks.

9 Page of APPENDIX I - PIPELINE RISK ASSESSMENT MODEL The Pipeline Risk Assessment Model is outlined in the following tables: Likelihood Factors and Variables External Corrosion Back to Back ILI Presence of back-to-back ILI runs for corrosion growth-rate analysis External Corrosion Rupture Threat Score Metric that measures interaction of density and severity of corrosion Internal Corrosion Back to Back ILI Presence of back-to-back ILI runs for corrosion growth-rate analysis Internal Corrosion Rupture Threat Score Metric that measures interaction of density and severity of corrosion Internal Corrosion Susceptibility Factor Indicator of the susceptibility to internal corrosion Cracking Age of Crack Tool Run Time since the last crack tool was run Age of Pipe Time since the pipe was manufactured and installed. Coating Type Coating type of the pipeline Crack Density Measure of the density of crack defects in the pipe. Cracking Failure History History of cracking on a given pipe section Distance Downstream from Pump Station Indicator of flow turbulence and pressure which impact fatigue cracking Yes Pipe Type Longitudinal weld type for the pipe section Pressure Cycling Severity Severity of the pressure cycling over a given pump stn to pump stn segment Time Since Alternate Crack Assessment An alternate crack assessment method has been used within years Rock Denting Age of Caliper / Geometry Run Time since last caliper / geometry run Age of Pipe Time since the pipe was manufactured and installed Denting Failure History History of denting on a given pipe section # Dents per Mile Number of dents per mile Appurtenances n-welded Appurtenances Presence of non-welded appurtenances in the pipe section Welded Appurtenances Presence of welded appurtenances in the pipe section Welded and Pressurized Appurtenances Presence of welded and pressurized appurtenances in the pipe section Welded and Protruding Appurtenances Presence of welded and protruded appurtenances in the pipe section

10 Page 0 of Third Party Damage Aerial Surveillance Frequency Aerial patrol of the right-of-way Areas of High Activity Amount of construction activity along the right-of-way Crossing Exposure Percentage of section length with crossings Crossing Types The types of crossings along the pipeline Dents on top of Pipe Top of pipe dent is indicative of third party activity Depth of Cover Depth of ground cover over the pipeline at any given location Farm Activity Amount of farming activity within 00m of the pipeline Foot Patrol Frequency The frequency of foot patrols along the pipe right-of-way Line Marking A measure of how clearly marked the pipe section is One Call Effectiveness Effectiveness of the one-call system in vicinity of pipeline One Call Violations One-call violations for a given section over the past year Public and Stakeholder Education Measure of public and stakeholder education ROW Condition Measure of the right-of-way condition Third Party Damage Prevention Third party prevention and mitigation techniques that may be in place for the given section of pipe Third Party Failures History of Third Party Failure on a given section of pipe Third Party Hits Presence of no-leak third party hits on the pipe section Vandalism Indicator of vandalism on the pipe section in the last five years Vehicle Patrol Frequency The frequency of vehicle patrol along the pipe right-of-way System Operations Abnormal Operating Conditions Abnormal Operating Conditions by 000 ft section per year Pressure Safety Systems (at facilities) Safety systems at facilities for mainline overpressure Natural Forces Earthquake History Identifies historical earthquakes in the vicinity of the pipeline Flooding History Identifies historical flood locations in the vicinity of the pipeline Lightning History Identifies historical lightning strikes on the pipe section Ground Movement Ground Instability Indicator of ground instability in the vicinity of the pipeline Ground Movement Monitoring Criteria Indicates the amount of ground movement and whether acceptable or not Seismic Activity or Area Natural or manmade seismic activity in vicinity of the pipeline Water Crossings Presence of water crossings Weights or Hold Downs Presence of weights or hold downs for water crossings

11 Page of Consequence Factors and Variables Impact on Population Direct HCA - Population High or Other Populated Area. Pipeline goes through the High Consequence Area ER Procedures Emergency Response Procedures are available ER Shared Resources Emergency Response Resources are available from others ER Simulations Emergency Response Simulations are held annually ER Training Emergency response training is held Initial Volume Loss - Rupture Estimated rupture volume out before isolation of the pipe section Yes Leak Detection Indicator that the pipe section has leak detection monitoring Mutual Aid Agreement Presence of a mutual aid agreement for the given pipe section Population Rural or Semi-rural Population Sensitive Areas Population areas of significance (e.g. school, church, hospital, etc.) within 00m of the pipeline Product Type Classification of the product being transported Stabilization Loss Potential drawdown volume out at a given pipe section location Transport HCA - Population High or Other Populated Area. Through a transport mechanism, a rupture on the pipeline could impact a populated area Impact on Environment Adjacent Land Use Land Use(s) adjacent to the pipeline Areas of Environmental Significance Environmentally sensitive areas (not HCAs) along pipeline Depth to Groundwater The depth below the surface to the top of the groundwater table Direct HCA - Environment Drinking water resource, environmental sensitive area, commercially navigable waterway. Pipeline goes through the High Consequence Area Dispersion Potential The dispersion potential is a measure of the steepness of the pipe elevation profile ER Procedures Emergency Response Procedures are available ER Shared Resources Emergency Response Resources are available from others ER Simulations Emergency Response Simulations are held annually ER Training Emergency Response training is held Initial Volume Loss - Rupture Estimated rupture volume out before isolation of the pipe section Yes Leak Detection Indicator that pipe section has leak detection monitoring Mutual Aid Agreement Presence of a mutual aid agreement for the given pipe section Product Type Classification of product being transported Seasonal Accessibility Measure of the difficulty in gaining access to the pipe section Stabilization Loss - Rupture Potential drawdown volume out at a given pipe section location Transport HCA - Environment Drinking Water Source, Environmentally Sensitive Area, Commercially Navigable Waterway. Through a transport mechanism, a rupture on the pipeline could impact an HCA. Impact on Business Access for Repairs Difficulty in gaining access to the pipe for repair. ER Procedures Emergency Response Procedures are available ER Shared Resources Emergency Response Resources are available from others ER Simulations Emergency Response Simulations are held annually ER Training Emergency Response training is held Leak Detection Indicator that pipe section has leak detection monitoring Mutual Aid Agreement Presence of a mutual aid agreement for the given pipe section Other Business Costs Costs associated with a failure not captured in Out of Service or Total Volume costs Out of Service Costs Costs associated with a failure resulting from the pipeline being out of service Redundancy Indicator of alternate supplier to customers in pipeline unavailable Seasonal Accessibility Measure of the difficulty in gaining access to the pipe section Total Volume Costs Costs associated with a failure resulting from the product lost from the system

12 Page of 0 APPENDIX II - RISK ASSESSMENT RESULTS In this Section, the results of the risk assessment for the current versus the reversed line flow and expanded capacity are compared..0 CURRENT LINE CONFIGURATION RISK ASSESSMENT RESULTS The current Line configuration risk assessment results used for the following comparison were generated in 00 and include data collection completed in LINE B REVERSAL RISK ASSESSMENT Three variables of the Pipeline Risk Assessment Model are impacted by the Project. These variables and the changes they undergo for the Project are provided in Table. Table - Variables Impacted by the Reversal of Line B and/or Capacity Increase Applicable Portion of the Project Line B Reversal Line Capacity Expansion Line Capacity Expansion Factor Variable Name Modeling Change Result Fatigue Cracking Impact on Population Impact on Environment Impact on Population Impact on Environment Distance Downstream from Station Initial Volume Loss Rupture Transport HCAs Data reflects change in flow direction. The initial volume out is the amount of product released at design flow rate before remote controlled valves are closed and the pipeline isolated. The increase in initial volume out with the capacity expansion is approximately m. The change in product flow rate yields an increase of initial volume out of m. This increase of volume out has minimum impact on overland transport impacts to HCAs Increase in modeled risk at the discharge side of a pump station; decrease in modeled risk at the suction side of a pump station. The increase in initial volume out with the Project yields a minor increase in risk for 0.% of Line. anticipated change in modeled risk.

13 Page of METRE RISK ASSESSMENT SECTIONS For the current Line B configuration, the 0-metre risk assessment sections begin at Montreal and are determined one after the other in the same manner until rth Westover. The last section may not be exactly 0 metres long. For the reversed configuration, the 0-metre sections begin in rth Westover and end in Montreal. Again, the last section may not be 0 metres long. Sections in the current configuration may not directly align with those in the reversed configuration. In the indexed Pipeline Risk Assessment Model, the scoring for a given assessment section is based on the worst case for each measured condition within that section. Because of the possible stationing differences discussed above, the worst cases may not line up exactly between current configuration and reversed configuration. As a result, for two risk sections in close alignment, there may be slight differences in the risk scores even when there are no data differences..0 RISK PROFILES In the pipeline risk assessment, risk is equal to assessed likelihood of a release multiplied by the assessed consequence that would result if a release were to occur. The risk results are generated for sections of pipe and graphed by stationing to yield a risk profile. The results of the risk profile are relative; that is, one section of pipe can be compared to another. The risk score itself has no meaning. 0.0 IDENTIFICATION OF RISK MITIGATION ACTIVITIES Operational Risk Management generates the pipeline risk assessment results and then presents these to Enbridge s Regional Operations in a facilitated session that examines what each Region can do to manage the identified high risk areas. In this session, Regional subject matter experts bring their own expertise or knowledge about the pipeline and the terrain through which it traverses, as input to the identification and prioritization of appropriate risk management activities..0 LINE B REVERSAL. LIKELIHOOD COMPARISON RESULTS Figures A and B illustrate the rth Westover to Montreal change in likelihood scores resulting from the proposed line reversal. At the Line B reversal suction end of the pump stations, the likelihood of a release decreases. At the Line B reversal discharge end of the pump stations, the likelihood of a release increases. These changes are due to the Distance Downstream from the Station variable scoring. Minor changes of likelihood scores throughout the remainder of the reversed pipeline are due to the stationing discrepancies noted earlier in this document.

14 Page of Likelihood Comparison - rth Westover to Montreal Hilton Station Cardinal Station Terrebonne Station Line Current Line Reversed KM Post Figure A Line B Current vs. Reversal Configuration: Likelihood Scores Likelihood Comparison - rth Westover to KP 0 Likelihood Comparison - Upstream & Downstream of Hilton Hilton Station Line Current Line Reversed Line Current Line Reversed KM Post KM Post Likelihood Comparison - Upstream & Downstream of Cardinal Likelihood Comparison KP to Montreal Cardinal Station Terrebonne Station Line Current Line Reversed Line Current Line Reversed KM Post KM Post Figure B Line B Current vs. Reversal Configuration: Likelihood Score Differences

15 Page of. CONSEQUENCE COMPARISON RESULTS Figure C provides the consequence scores resulting from the Line B reversal. 0 Consequence Comparison - rth Westover to Montreal Hilton Station Cardinal Station Terrebonne Station Line Current Line Reversed KM Post 0 Figure C Line B Current vs. Reversal Configuration: Consequence Scores Minor changes in consequence scores for the Line B reversal section are due to the stationing discrepancies described earlier in this document. There is no expected change to the consequence with the reversal of Line B.. RISK COMPARISON The previous sections present the changes to likelihood and consequence resulting from the Line B reversal. The risk profile changes illustrated in Figure D are a result of those changes. The difference between station to station endpoints is due to the effect of the variable Distance Downstream from the Pump Station as previously described. Minor changes in risk scores for the Line B reversal are due to the stationing discrepancies described earlier in this document. Overall the changes to the risk are minor. The risk control and mitigation strategies currently being executed by Enbridge as outlined in the Engineering Assessment manage this risk.

16 Page of Risk Comparison - rth Westover to Montreal Hilton Station Cardinal Station Terrebonne Station 0 Line Current Line Reversed KM Post Figure D Risk Profile for Line B Current Configuration vs. Reversed Flow 0.0 LINE CAPACITY EXPANSION The Line capacity expansion portion of the Project yields an increase in calculated initial volume out and this increase results in an increase in both assessed consequence and risk for 0.% of Line. The effect of this capacity expansion on consequence and risk is presented in the following two sections. For the consequence and risk results presented in these sections, Line was modeled in reverse flow so that the changes represented here are those due solely to the capacity increase.. CONSEQUENCE COMPARISON RESULTS Figure E provides the Line consequence scores resulting from the increase in capacity.

17 Page of Figure E Line Capacity Increase: Consequence Scores. RISK COMPARISON The change in risk resulting from the potential increase in capacity is presented in Figure F. Minor changes in the risk scores throughout Line may also be due to the stationing discrepancies described earlier in this document. Overall, the changes to the assessed risk are minor. The risk control and mitigation strategies currently being executed by Enbridge outlined in the Pipeline Engineering Assessment manage this risk.

18 Page of Figure F Line Capacity Increase: Risk Results