GTG incident on 2014-11-26 — TX

Operator
Anr Pipeline Co
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$500,000
Incident datetime
2014-11-26 12:00
Report number
Location
TX
Narrative
On 26 november 2014 during a flight over the gulf of mexico, an transcanada/ anr pipeline company (anr) technician observed a potential leak near tc offshore (tco) assets in the outer continental shelf (ocs) eugene island block 55 (ei-55). The leak was reported to anr, operator for tc offshore, as a bubbling pattern approximately two feet in diameter over tc offshore's 733 transmission pipeline at approximate milepost 40.8 (29.24206280, -91.50513440). Following the report of the incident to the national response center, transcanada/anr maintained contact and updated regularly u.S. Coast guard, bsee, and PHMSA. While preparing to dispatch an investigation and repair vessel to the site, anr scheduled aerial patrols twice daily to monitor the leak. No sheen or product was documented at the site for the duration of the leak and repair. The repair vessel and contract employees arrived at the incident location on 3 december to begin exposing the pipe for the leak investigation. Cover material jetting and concrete removal at the leak site was completed on 8 december. Observation and investigation by the divers determined that the leak was located at the twelve o'clock position in the longitudinal seam 45 inches downstream of a girth weld. During the cover material removal, ultrasonic tests to determine the possibility of metal loss were conducted on the pipeline at two locations upstream and downstream of leak area. These tests indicated no metal loss to the pipeline. Upon discovery of the leak location, anr decided to isolate the pipeline segment, reduce the pressure on the line, and perform additional testing and analysis to determine the most effective repair. On 13 december, subsea valve 733-1a-2 located at eugene island block 63 (ei-63) was closed, isolating the 733 pipeline between ei-63 and anr's patterson compressor station located in st. Mary parish, louisiana. Additionally, the producer, castex, was shut-in and the valve was closed at eugene island block 18. Pressure on the 733 line was reduced from approximately 800 psig to 400 psig and flared at the patterson compressor station. Following the reduction in pressure, time of flight diffraction non-destructive testing (ndt) was conducted on 15 december 2014 to determine the characteristics and location of leak. The area inspected included one foot upstream and one foot downstream of the anomaly area. Testing indicated a small defect located within the longitudinal seam with no indication of cracks or lack of fusion. On 18 december at 05:00 cst, a plidco bolt-on clamp was successfully installed over the leak location by qualified contract employees. The clamp is considered a permanent repair. Following the installation of the clamp, pipeline pressure was increased, the producer valve at ei-18 was allowed to resume flowing, and the subsea valve at ei-63 will be reopened when it can be safely accessed. There were no indications of further leakage at the repair location.
Detailed record list
Report Received Date
2014-12-22 00:00:00
Iyear
2014
Report Number
20140147
Supplemental Number
16659
Report Type
Supplemental Final
Operator Id
Name
Anr Pipeline Co
Operator Street Address
700 Louisiana Street Suite 700
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Local Datetime
2014-11-26 12:00:00
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2014-11-26 13:14:00
Commodity Released Type
Natural Gas
Unintentional Release
2500
Intentional Release
12000
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2014-12-13 00:05:00
Restart Datetime
2014-12-18 05:00:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2014-11-26 12:00:00
On Site Datetime
2014-12-03 13:00:00
On Off Shore
Offshore
Off Water Depth
15
Off Accident Origin
On The Outer Continental Shelf (Ocs)
Off Ocs Area
Eugene Island
Off Ocs Block
55
Off Area Accident Type
Below Water, Pipe Buried Or Jetted Below Seabed
Pipe Facility Type
Interstate
System Part Involved
Offshore Pipeline, Including Riser And Riser Bend
Item Involved
Pipe
Pipe Type
Pipe Seam
Pipe Diameter
20
Pipe Wall Thickness
0.406
Pipe Smys
52000
Pipe Specification
Api 5l
Pipe Seam Type
Dsaw
Pipe Manufacturer
United States Steel
Pipe Coating Type
Coal Tar
Installation Year
1965
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Pinhole
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
506
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
10425
Est Cost Intentional Release
49440
Est Cost Prop Damage
500000
Est Cost Emergency
0
Est Cost Other
0
Prpty
559865
Accident Psig
905
Mop Psig
1050
Mop Cfr Section
192.619(A)(1)
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Upstream Valve Type Ind
Manual
Downstream Valve Type Ind
Manual
Length Segment Isolated
184800
Internal Inspection Ind
No
Tight Mitered 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
Operator Employee
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 small size of the defect(pinhole leak) and the small amount of gas leaking would not be detectable by the controllers or control room.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Material Failure Of Pipe Or Weld
Cause Details
Original Manufacturing-Related (Not Girth Weld Or Other Welds Formed In The Field)
Pwjf Failure Type
Original Manufacturing-Related (Not Girth Weld Or Other Welds Formed In The Field)
Field Exam Ind
Yes
Metallurgical Ind
Yes
Other Factor
Yes
Other Factor Details
Weld Anomoly
Pwf Additional Other Ind
Yes
Additional Other Details
Pinhole In Weld
Collected Data Ind
No
Has Hydrtst Conduc Before Ind
No
Direct Asmnt Conducted
No
Non Destructive Exam Ind
Yes
Exm Handl Ultrasonic Rcnt Year
2014
Exm Other Type
Time Of Flight Diffraction (Tofd)
Exm Other Rcnt Year
2014
Exm Handl Ultrasonic Rcnt Ind
Yes
Exm Other Rcnt Ind
Yes
Preparer Name
R**** R* S*****
Preparer Title
Field Compliance Specialist
Preparer Email
R***********@t**********.com
Preparer Telephone
6154655123
Authorizer Name
R***** L******
Authorizer Title
Manager U.s. Regulatory Compliance
Authorizer Telephone
(402)492-7454
Authorizer Email
R**********@t**********.com
Narrative
On 26 november 2014 during a flight over the gulf of mexico, an transcanada/ anr pipeline company (anr) technician observed a potential leak near tc offshore (tco) assets in the outer continental shelf (ocs) eugene island block 55 (ei-55). The leak was reported to anr, operator for tc offshore, as a bubbling pattern approximately two feet in diameter over tc offshore's 733 transmission pipeline at approximate milepost 40.8 (29.24206280, -91.50513440). Following the report of the incident to the national response center, transcanada/anr maintained contact and updated regularly u.S. Coast guard, bsee, and PHMSA. While preparing to dispatch an investigation and repair vessel to the site, anr scheduled aerial patrols twice daily to monitor the leak. No sheen or product was documented at the site for the duration of the leak and repair. The repair vessel and contract employees arrived at the incident location on 3 december to begin exposing the pipe for the leak investigation. Cover material jetting and concrete removal at the leak site was completed on 8 december. Observation and investigation by the divers determined that the leak was located at the twelve o'clock position in the longitudinal seam 45 inches downstream of a girth weld. During the cover material removal, ultrasonic tests to determine the possibility of metal loss were conducted on the pipeline at two locations upstream and downstream of leak area. These tests indicated no metal loss to the pipeline. Upon discovery of the leak location, anr decided to isolate the pipeline segment, reduce the pressure on the line, and perform additional testing and analysis to determine the most effective repair. On 13 december, subsea valve 733-1a-2 located at eugene island block 63 (ei-63) was closed, isolating the 733 pipeline between ei-63 and anr's patterson compressor station located in st. Mary parish, louisiana. Additionally, the producer, castex, was shut-in and the valve was closed at eugene island block 18. Pressure on the 733 line was reduced from approximately 800 psig to 400 psig and flared at the patterson compressor station. Following the reduction in pressure, time of flight diffraction non-destructive testing (ndt) was conducted on 15 december 2014 to determine the characteristics and location of leak. The area inspected included one foot upstream and one foot downstream of the anomaly area. Testing indicated a small defect located within the longitudinal seam with no indication of cracks or lack of fusion. On 18 december at 05:00 cst, a plidco bolt-on clamp was successfully installed over the leak location by qualified contract employees. The clamp is considered a permanent repair. Following the installation of the clamp, pipeline pressure was increased, the producer valve at ei-18 was allowed to resume flowing, and the subsea valve at ei-63 will be reopened when it can be safely accessed. There were no indications of further leakage at the repair location.
Report Received Date 2014-12-22 00:00:00
Iyear 2014
Report Number 20140147
Supplemental Number 16659
Report Type Supplemental Final
Operator Id 405 PHMSA Enforcement
Name Anr Pipeline Co
Operator Street Address 700 Louisiana Street Suite 700
Operator City Name Houston
Operator State Abbreviation TX
Operator Postal Code 77002
Local Datetime 2014-11-26 12:00:00
Location Latitude 29.2420628 Google Maps OpenStreetMap
Location Longitude -91.5051344 Google Maps OpenStreetMap
Nrc Rpt Num 1102064 NRC Report How to search
Nrc Rpt Datetime 2014-11-26 13:14:00
Commodity Released Type Natural Gas
Unintentional Release 2500
Intentional Release 12000
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind Yes
Shutdown Datetime 2014-12-13 00:05:00
Restart Datetime 2014-12-18 05:00:00
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2014-11-26 12:00:00
On Site Datetime 2014-12-03 13:00:00
On Off Shore Offshore
Off Water Depth 15
Off Accident Origin On The Outer Continental Shelf (Ocs)
Off Ocs Area Eugene Island
Off Ocs Block 55
Off Area Accident Type Below Water, Pipe Buried Or Jetted Below Seabed
Pipe Facility Type Interstate
System Part Involved Offshore Pipeline, Including Riser And Riser Bend
Item Involved Pipe
Pipe Type Pipe Seam
Pipe Diameter 20
Pipe Wall Thickness 0.406
Pipe Smys 52000
Pipe Specification Api 5l
Pipe Seam Type Dsaw
Pipe Manufacturer United States Steel
Pipe Coating Type Coal Tar
Installation Year 1965
Manufactured Year Unknown
Material Involved Carbon Steel
Release Type Leak
Leak Type Pinhole
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 506
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 10425
Est Cost Intentional Release 49440
Est Cost Prop Damage 500000
Est Cost Emergency 0
Est Cost Other 0
Prpty 559865
Accident Psig 905
Mop Psig 1050
Mop Cfr Section 192.619(A)(1) 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 184800
Internal Inspection Ind No
Tight Mitered 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 Operator Employee
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 small size of the defect(pinhole leak) and the small amount of gas leaking would not be detectable by the controllers or control room.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Material Failure Of Pipe Or Weld
Cause Details Original Manufacturing-Related (Not Girth Weld Or Other Welds Formed In The Field)
Pwjf Failure Type Original Manufacturing-Related (Not Girth Weld Or Other Welds Formed In The Field)
Field Exam Ind Yes
Metallurgical Ind Yes
Other Factor Yes
Other Factor Details Weld Anomoly
Pwf Additional Other Ind Yes
Additional Other Details Pinhole In Weld
Collected Data Ind No
Has Hydrtst Conduc Before Ind No
Direct Asmnt Conducted No
Non Destructive Exam Ind Yes
Exm Handl Ultrasonic Rcnt Year 2014
Exm Other Type Time Of Flight Diffraction (Tofd)
Exm Other Rcnt Year 2014
Exm Handl Ultrasonic Rcnt Ind Yes
Exm Other Rcnt Ind Yes
Preparer Name R**** R* S*****
Preparer Title Field Compliance Specialist
Preparer Email R***********@t**********.com
Preparer Telephone 6154655123
Authorizer Name R***** L******
Authorizer Title Manager U.s. Regulatory Compliance
Authorizer Telephone (402)492-7454
Authorizer Email R**********@t**********.com
Narrative On 26 november 2014 during a flight over the gulf of mexico, an transcanada/ anr pipeline company (anr) technician observed a potential leak near tc offshore (tco) assets in the outer continental shelf (ocs) eugene island block 55 (ei-55). The leak was reported to anr, operator for tc offshore, as a bubbling pattern approximately two feet in diameter over tc offshore's 733 transmission pipeline at approximate milepost 40.8 (29.24206280, -91.50513440). Following the report of the incident to the national response center, transcanada/anr maintained contact and updated regularly u.S. Coast guard, bsee, and PHMSA. While preparing to dispatch an investigation and repair vessel to the site, anr scheduled aerial patrols twice daily to monitor the leak. No sheen or product was documented at the site for the duration of the leak and repair. The repair vessel and contract employees arrived at the incident location on 3 december to begin exposing the pipe for the leak investigation. Cover material jetting and concrete removal at the leak site was completed on 8 december. Observation and investigation by the divers determined that the leak was located at the twelve o'clock position in the longitudinal seam 45 inches downstream of a girth weld. During the cover material removal, ultrasonic tests to determine the possibility of metal loss were conducted on the pipeline at two locations upstream and downstream of leak area. These tests indicated no metal loss to the pipeline. Upon discovery of the leak location, anr decided to isolate the pipeline segment, reduce the pressure on the line, and perform additional testing and analysis to determine the most effective repair. On 13 december, subsea valve 733-1a-2 located at eugene island block 63 (ei-63) was closed, isolating the 733 pipeline between ei-63 and anr's patterson compressor station located in st. Mary parish, louisiana. Additionally, the producer, castex, was shut-in and the valve was closed at eugene island block 18. Pressure on the 733 line was reduced from approximately 800 psig to 400 psig and flared at the patterson compressor station. Following the reduction in pressure, time of flight diffraction non-destructive testing (ndt) was conducted on 15 december 2014 to determine the characteristics and location of leak. The area inspected included one foot upstream and one foot downstream of the anomaly area. Testing indicated a small defect located within the longitudinal seam with no indication of cracks or lack of fusion. On 18 december at 05:00 cst, a plidco bolt-on clamp was successfully installed over the leak location by qualified contract employees. The clamp is considered a permanent repair. Following the installation of the clamp, pipeline pressure was increased, the producer valve at ei-18 was allowed to resume flowing, and the subsea valve at ei-63 will be reopened when it can be safely accessed. There were no indications of further leakage at the repair location.

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