GTG incident on 2011-05-24 — TX

Operator
Northwest Pipeline Corp (Wgp)
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$68,500
Incident datetime
2011-05-24 12:30
Report number
Location
TX
Narrative
During the annual pocatello air patrol of the pipeline, a location with dead vegetation was identified at mile post 554.6. A ground patrol was sent to investigate and found the dead vegetation and used a flame pack to identify leaking gas. By probing and sniffing, it was determined that the leak was on the 24" 1401 loop line. The pipeline was immediately blown down to 43 psig from mlv 8l-2. Excavation machinery was brought on site and began excavation. The pipe was found sitting on a rock and gas was escaping from that location. The blow down continued to a slight positive pressure. A tempory patch was put over the hole for the night. The following morning the pipe was cut and a 7.81 ft pup was installed.
Detailed record list
Report Received Date
2011-06-15 00:00:00
Iyear
2011
Report Number
20110184
Supplemental Number
15275
Report Type
Supplemental Final
Operator Id
Name
Northwest Pipeline Corp (Wgp)
Operator Street Address
2800 Post Oak Blvd
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77056
Local Datetime
2011-05-24 12:30:00
Location Latitude
Location Longitude
-111.8576021
Nrc Rpt Num
Nrc Rpt Datetime
2011-05-24 17:47:00
Commodity Released Type
Natural Gas
Unintentional Release
1920
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2011-05-24 18:48:00
Restart Datetime
2011-06-21 14:00:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2011-05-24 12:30:00
On Site Datetime
2011-05-24 12:30:00
On Off Shore
Onshore
Onshore State Abbreviation
Id
Onshore Postal Code
83246
Onshore City Name
Lava
Onshore County Name
Caribou
Designated Location
Milepost
Designated Name
M.p. 554.6
Pipe Fac Name
Ignacio To Sumas 1401 Loop Line
Segment Name
1401 Ln Mlv 8l1 To 8l2
Federal
No
Location Type
Pipeline Right-Of-Way
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
96
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
24
Pipe Wall Thickness
0.25
Pipe Smys
60000
Pipe Specification
Api 5l Grade X60
Pipe Seam Type
Longitudinal Erw - High Frequency
Pipe Manufacturer
American Pipe
Pipe Coating Type
Epoxy
Installation Year
1992
Manufactured Year
1992
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
445
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
7680
Est Cost Intentional Release
62180
Est Cost Prop Damage
68500
Est Cost Emergency
0
Est Cost Other
0
Prpty
138360
Accident Psig
713
Mop Psig
850
Mop Cfr Section
Not On Omb-Approved Form When Submitted
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Manual
Length Segment Isolated
87869
Internal Inspection Ind
Yes
Operation Complications Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Air Patrol
Operator Type
Contractor Working For The Operator
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
The pipe was sitting on a rock that dented the pipe creating a crack in the pipe causing a slow leak. The gas release was so minute, it was not detectable with the scada monitored system.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Material Failure Of Pipe Or Weld
Cause Details
Design-, Construction-, Installation-, Or Fabrication-Related
Pwjf Failure Type
Design-, Construction-, Installation-, Or Fabrication-Related
Field Exam Ind
Yes
Mechanical Stress
Yes
Additional Dent Ind
Yes
Additional Crack Ind
Yes
Collected Data Ind
Yes
Axial Magnetic Flx Lkg Ind
Yes
Geometry Deformation Ind
Yes
Axial Recent Year
2010
Geometry Recent Year
2010
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
No
Preparer Name
B*** S****
Preparer Title
Senior Technical Specialist
Preparer Email
B*********@w*******.com
Preparer Telephone
801-584-6741
Authorizer Name
B*** S****
Authorizer Title
Senior Technical Specialist
Authorizer Telephone
801-584-6741
Authorizer Email
B*********@w*******.com
Narrative
During the annual pocatello air patrol of the pipeline, a location with dead vegetation was identified at mile post 554.6. A ground patrol was sent to investigate and found the dead vegetation and used a flame pack to identify leaking gas. By probing and sniffing, it was determined that the leak was on the 24" 1401 loop line. The pipeline was immediately blown down to 43 psig from mlv 8l-2. Excavation machinery was brought on site and began excavation. The pipe was found sitting on a rock and gas was escaping from that location. The blow down continued to a slight positive pressure. A tempory patch was put over the hole for the night. The following morning the pipe was cut and a 7.81 ft pup was installed.
Report Received Date 2011-06-15 00:00:00
Iyear 2011
Report Number 20110184
Supplemental Number 15275
Report Type Supplemental Final
Operator Id 13845 PHMSA Enforcement
Name Northwest Pipeline Corp (Wgp)
Operator Street Address 2800 Post Oak Blvd
Operator City Name Houston
Operator State Abbreviation TX
Operator Postal Code 77056
Local Datetime 2011-05-24 12:30:00
Location Latitude 42.62059498 Google Maps OpenStreetMap
Location Longitude -111.8576021 Google Maps OpenStreetMap
Nrc Rpt Num 977297 NRC Report How to search
Nrc Rpt Datetime 2011-05-24 17:47:00
Commodity Released Type Natural Gas
Unintentional Release 1920
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind Yes
Shutdown Datetime 2011-05-24 18:48:00
Restart Datetime 2011-06-21 14:00:00
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2011-05-24 12:30:00
On Site Datetime 2011-05-24 12:30:00
On Off Shore Onshore
Onshore State Abbreviation Id
Onshore Postal Code 83246
Onshore City Name Lava
Onshore County Name Caribou
Designated Location Milepost
Designated Name M.p. 554.6
Pipe Fac Name Ignacio To Sumas 1401 Loop Line
Segment Name 1401 Ln Mlv 8l1 To 8l2
Federal No
Location Type Pipeline Right-Of-Way
Incident Area Type Underground
Incident Area Subtype Under Soil
Depth Of Cover 96
Crossing No
Pipe Facility Type Interstate
System Part Involved Onshore Pipeline, Including Valve Sites
Item Involved Pipe
Pipe Type Pipe Body
Pipe Diameter 24
Pipe Wall Thickness 0.25
Pipe Smys 60000
Pipe Specification Api 5l Grade X60
Pipe Seam Type Longitudinal Erw - High Frequency
Pipe Manufacturer American Pipe
Pipe Coating Type Epoxy
Installation Year 1992
Manufactured Year 1992
Material Involved Carbon Steel
Release Type Leak
Leak Type Crack
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 445
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 7680
Est Cost Intentional Release 62180
Est Cost Prop Damage 68500
Est Cost Emergency 0
Est Cost Other 0
Prpty 138360
Accident Psig 713
Mop Psig 850
Mop Cfr Section Not On Omb-Approved Form When Submitted View CFR 49 §192
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Upstream Valve Type Ind Manual
Downstream Valve Type Ind Manual
Length Segment Isolated 87869
Internal Inspection Ind Yes
Operation Complications Ind No
Pipeline Function Transmission System
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind No
Scada Conf Ind No
Accident Identifier Air Patrol
Operator Type Contractor Working For The Operator
Investigation Status No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details The pipe was sitting on a rock that dented the pipe creating a crack in the pipe causing a slow leak. The gas release was so minute, it was not detectable with the scada monitored system.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Material Failure Of Pipe Or Weld
Cause Details Design-, Construction-, Installation-, Or Fabrication-Related
Pwjf Failure Type Design-, Construction-, Installation-, Or Fabrication-Related
Field Exam Ind Yes
Mechanical Stress Yes
Additional Dent Ind Yes
Additional Crack Ind Yes
Collected Data Ind Yes
Axial Magnetic Flx Lkg Ind Yes
Geometry Deformation Ind Yes
Axial Recent Year 2010
Geometry Recent Year 2010
Has Hydrtst Conduc Before Ind No
Direct Asmnt Conducted No
Non Destructive Exam Ind No
Preparer Name B*** S****
Preparer Title Senior Technical Specialist
Preparer Email B*********@w*******.com
Preparer Telephone 801-584-6741
Authorizer Name B*** S****
Authorizer Title Senior Technical Specialist
Authorizer Telephone 801-584-6741
Authorizer Email B*********@w*******.com
Narrative During the annual pocatello air patrol of the pipeline, a location with dead vegetation was identified at mile post 554.6. A ground patrol was sent to investigate and found the dead vegetation and used a flame pack to identify leaking gas. By probing and sniffing, it was determined that the leak was on the 24" 1401 loop line. The pipeline was immediately blown down to 43 psig from mlv 8l-2. Excavation machinery was brought on site and began excavation. The pipe was found sitting on a rock and gas was escaping from that location. The blow down continued to a slight positive pressure. A tempory patch was put over the hole for the night. The following morning the pipe was cut and a 7.81 ft pup was installed.

All rights reserved. Copyright © by ClearPHMSA