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OPS ECDA Workshop. David Berger & Alan Eastman KeySpan Corporation Pacific Gas & Electric Houston, TX November 4, 2003. KeySpan Gas Transmission System Summary. Distance (miles). Less than 20% 20 to 30% Greater than Totals . SMYS. PG&E Gas Transmission System Summary.
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OPS ECDA Workshop David Berger & Alan Eastman KeySpan Corporation Pacific Gas & Electric Houston, TX November 4, 2003
KeySpan Gas TransmissionSystem Summary Distance (miles) Less than 20% 20 to 30% Greater than Totals SMYS OPS ECDA Public Meeting
PG&E Gas TransmissionSystem Summary Distance (miles) Class 1 Class 2 Class 3 Class 4 OPS ECDA Public Meeting
IMP Tools • Pressure Test • In Line Inspection (a.k.a. Pigging) • Direct Assessment (a.k.a. DA) • Other OPS ECDA Public Meeting
ECDA Process OPS ECDA Public Meeting
ECDA Steps • Step 1 - Pre Assessment - Dave Berger • Step 2 - Indirect Examination - D. Berger • Step3 - Direct Examination - Alan Eastman • Step 4 - Post Assessment - A. Eastman OPS ECDA Public Meeting
ECDA Step 1 - Pre Assessment • Determine what you know about the main in Question • Determine what threats are being encountered OPS ECDA Public Meeting
ECDA Step 1 - Pre Assessment • Determine the Relative Risk of this Segment • Run Risk Model if Available OPS ECDA Public Meeting
Feasibility Analysis Report Step 1 Pre-Assessment Is the ECDA process technically, practically and economically feasible ? OPS ECDA Public Meeting
IIT Selection Tool Form OPS ECDA Public Meeting
Region Assignment Form OPS ECDA Public Meeting
ECDA Step 2 - Indirect Examination • Tool Selection based on Pipe and Threats • Integrate Pre-Assessment information into Indirect Exam Process • Pipe Region • Tool Types • Expected Results • Data Collection OPS ECDA Public Meeting
Step 2 – Indirect Examinations • Other Logistical Issues: • Home owner notification • CIS through asphalt • City permits Dear Landowner, Recently we sent you a letter notifying you that we would be performing some testing of the natural gas pipeline on your property. As a reminder, the testing will not cause an interruption of your gas service. We are planning to be testing the pipeline in your area next week. If we need to gain access to your backyard, we will contact you in person at the time of the testing. In the event that nobody is home, we will plan to come back and test your property at some future date, most probably on a Saturday. However, please contact our testing Contractor, Mears, at 925-820-7630 if it is acceptable for us to enter your backyard and perform the testing in your absence. The testing will only take approximately 5 minutes per residence. Thanks for your cooperation. PG&E OPS ECDA Public Meeting
25’ Interval OPS ECDA Public Meeting
5’ Interval OPS ECDA Public Meeting
ECDA Step 2 • Tool Selection based on Pipe and Threats • Major Threats to LDC’s are Corrosion and Third Party Damage • External Corrosion • Internal Corrosion (Dependent on gas quality) • SCC Not a Problem • First and Second party Damage also an issue OPS ECDA Public Meeting
ECDA Step 2 • Integrate Pre-Assessment information into Indirect Examination Process • Check for CP History • Coating Type and Recent Examinations • Tool Environment • Special Situations OPS ECDA Public Meeting
ECDA Step 2 • Pipe Region • Tool Changes Requires Region Change • Soil Type and Corrosion History May Change Region • Coating Type May Change Region • Pipe Type May Change Region • Pipe Diameter May Not Change Region • Threat Change Requires Region Change OPS ECDA Public Meeting
ECDA Step 2 • Tool Types • CIS: DC Electrical • PCM: Near DC but AC • DCVG: DC Gradient • ACVG: Near DC but AC • Soil Resistivity: Corrosion Rates • Bacterial: MIC Presence • C scan: AC Electrical OPS ECDA Public Meeting
ECDA Step 2 • Expected Results • Based On Threats, What do You Expect to Find • For Corrosion • Coating Damage, Disbondment, Shielding • In Areas with Poor CP, External Corrosion • With Wet Gas, Internal Corrosion • Near Dumps, MIC • Third Party Damage • Coating Damage (Maybe Pipe Damage) OPS ECDA Public Meeting
ECDA Step 2 • Data Collection • Manual or Automatic • Data Storage • Data Retrieval • Data Displays OPS ECDA Public Meeting
GM 33 OPS ECDA Public Meeting
GM 33 OPS ECDA Public Meeting
GM 33 OPS ECDA Public Meeting
GM 33 OPS ECDA Public Meeting
GM 33 OPS ECDA Public Meeting
Part 2 Now Alan will take you through the next two steps
Indirect Inspection Classification(example) CIS Severe……All of the following must exist: • ·Less than 600 mv off • ·200 mv depression over baseline • ·Convergence of on/off potential • ·Other condition that the PE wants to document • ·<500 off (any case) CIS Moderate…...All of the following must exist: • ·Less than 600 mv off • ·200 mv depression over baseline • ·Other condition that the PE wants to document CIS Minor……Any of the following can exist: • ·Between 600 to 850 mv off • ·Other conditions that the PE wants to document OPS ECDA Public Meeting
Prioritization Criteria I = Immediate S = Scheduled M = Monitored NI = No Indication OPS ECDA Public Meeting
CGT Scope • 2192 miles to assess 1673 miles of “covered” transmission lines • 1,273 miles of ECDA ($35,177,000) • 394 miles assessed during 913 miles of ILI ($98,500,000) • 6.5 miles of Pipeline Replacement ($6,500,000) 2004 Scope • ECDA – 117 miles ($5.8 million) • ILI – 79 miles ($12 million) • CIS – ($400,000) • Pipe Replacement – ($2,000,000) OPS ECDA Public Meeting
All pipeline companies will allocate the appropriate resources to ensure the integrity pipelines with the highest consequences of failure OPS ECDA Public Meeting
Step 3 – Direct Examination • Number of excavations per RP0502 • All immediate indications must be excavated (may be re-prioritized after a portion is excavated) • At least 1 scheduled dig per region • Effectiveness digs • First ECDA digs OPS ECDA Public Meeting
Direct Examination • Inspections • Remaining Strength Assessment • Root Cause Analysis • Reprioritization OPS ECDA Public Meeting
Recategorization Work In Progress OPS ECDA Public Meeting
Post Assessment • Remaining Life Calculations • Re-Assessment Intervals • ECDA Effectiveness Validation • Documentation OPS ECDA Public Meeting
Lessons Learned • Establishment of ECDA procedure has been a corner stone of program • Permit Applications time consuming and challenging • Landowner Notifications time consuming • Establishing GIS procedure is critical • IIT methods work • IIT results has aligned well and is rational • ECDA process appears to be working well We are sure there are more lessons to be learned!! OPS ECDA Public Meeting
Example of an ECDA Line 132 Through Silicon Valley Selection Criteria • Identified by Risk Management Program • Primary Threat – EC • Not piggable • 8 OD changes • 10 plug valves OPS ECDA Public Meeting
L-132 Near Major Theme Park • 20 mile section in study area • 24-34 inch, 400# MAOP, 20 to 40% SMYS, 1944 HAA, 1974 Tape • 13 Integrity Management Areas (IMAs) • 6300’ under streets, • 6000’ under concrete, • 4950’ under soil, • 2300’ in paved parking, • 2150’ in backyards OPS ECDA Public Meeting
Results of Classification • Good alignment between techniques • CP was protecting poorly coated section of pipe • Results appear rational OPS ECDA Public Meeting
Results of Prioritization Total of 10 Excavations OPS ECDA Public Meeting
Example of Line 132 Excavation Data Data Element Dig 1 Dig 2 ECDA Region 132-1 132-2 Coating Type Wrap HAA Pipe-to-Soil (-mV) 1051 971 Soil Resistivity 684 684 Coating Condition Partially Disbonded Partially Disbonded Liquid underneath coating Yes Yes Soil pH 5.5 6.0 Pipe pH 7.4 8.0 Corrosion No Yes Pit Depth (inches) 0.015 to 0.031 OPS ECDA Public Meeting
Final Outcome • 500 feet of recoating • 1650 feet of pipe replacement • Remaining indications reprioritized • Re-assessment interval being determined OPS ECDA Public Meeting
Site Three Poor Condition Excavate 10 ft. Excavated, removed coating, sandblasted
ECDA The End (I Thought They would Never Finish) OPS ECDA Public Meeting