Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2014-11-24 — OK
Operator
Transcontinental Gas Pipe Line Company
Cause
Corrosion Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$275,000
Incident datetime
2014-11-24 12:45
Report number
Location
OK
Narrative
11-24-2014 transcontinental's (transco) schriever operations district was contacted by coast guard regarding bubbles that had been sited in the vicinty of transco's facilities (area/block ss 7). The coordinates that were recieved from the coast guard were plotted by the schriever operations team. Transco's 16" & 20" gas gathering pipelines near the suspect leak location were isolated and blown down. Transco's support engineer begins the process of contacting contractor dive teams and equipment to investigate and repair the leak. Once the blow down of the lines was complete the 16" line was identified as the leaking line. 11-28-2014 the dive team begins cleaning the line and initiates the investigation. A ut reading of the leaking line is performed by the dive team. A repair clamp has been installed on the leak 11-30-2014. The line is repressured and back in full service 12-1-2014. The results of the investigation "shown below" determined the most probable cause of the leak on the 16" gas gathering pipeline was due to internal corrosion. The location of the leak on the pipe was at the 7 o'clock position. The ut inspection results showed no external corrosion or damage on the pipeline. A low flow unprocessed & undehydrated gas is transported through the pipeline since 1990. Transco does review every internal corrosion leak and follows it's pocedures to prevent and mitigate these types of enviroment. - this line has been transporting unprocessed and undehydrated gas since 1990 and has been treated since 1990 with corrosion inhibitors & biocides. - samples are collected & residuals are monitored monthly. - field techs monitor the chemical quantities and chemical injection pump operations on a monthly basis. - transco's corrosion engineers and smes review every internal corrosion leak that occur on thier systems and make reccomendations as needed.
Detailed record list
Report Received Date
2014-12-17 00:00:00
Iyear
2014
Report Number
20140138
Supplemental Number
16579
Report Type
Supplemental Final
Operator Id
19570
Name
Transcontinental Gas Pipe Line Company
Operator Street Address
One Williams Center Md 43-4
Operator City Name
Tulsa
Operator State Abbreviation
OK
Operator Postal Code
74172
Local Datetime
2014-11-24 12:45:00
Location Latitude
29.1857416
Location Longitude
91.1733138
Nrc Rpt Num
1101890
Nrc Rpt Datetime
2014-11-24 14:05:00
Commodity Released Type
Natural Gas
Unintentional Release
50
Intentional Release
3598
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2014-11-24 15:45:00
Restart Datetime
2014-11-30 15:20:00
Ignite Ind
No
Explode Ind
No
Incident Identified Datetime
2014-11-24 12:45:00
On Site Datetime
2014-11-24 12:45:00
On Off Shore
Offshore
Off Water Depth
9
Off Accident Origin
On The Outer Continental Shelf (Ocs)
Off Ocs Area
Ship Shoal
Off Ocs Block
7
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 Body
Pipe Diameter
16
Pipe Wall Thickness
0.312
Pipe Smys
52000
Pipe Specification
Api 5l
Pipe Seam Type
Flash Welded
Pipe Manufacturer
A.o Smith
Pipe Coating Type
Other
Pipe Coating Details
Asphalt With 3" Concrete Overlayed.
Installation Year
1959
Manufactured Year
1959
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Pinhole
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
418
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
10
Est Cost Intentional Release
13150
Est Cost Prop Damage
275000
Est Cost Emergency
5000
Est Cost Other
5000
Est Cost Other Details
Labor
Prpty
298160
Accident Psig
740
Mop Psig
1440
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
58450
Internal Inspection Ind
No
Other Inspection Ind
Yes
Internal Inspection Details
Launching And Receiving Pig Traps Are Not Designed To Handle A Smart Pig.
Operation Complications Ind
Yes
Low Flow Ind
Yes
Other Complications Ind
Yes
Inspect Comp Details
Low Pressure Unprocessed Gas.
Pipeline Function
Offshore Gathering
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Notification From Emergency Responder
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 leak with minimal pressure loss generated from the leak was undetectable by this method.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Corrosion Failure
Cause Details
Internal Corrosion
Internal External
Internal Corrosion
Int Visual Exam Results
Not Cut Open
Int Other Corrosion Ind
Yes
Int Corrosion Type Details
This Pipeline Has Been In Unprocessed And Undehydrated Service Since 1990. This Line Has Been Treated Since 1990 With Corrosion Inhibitors & Biocides. Samples Are Collected & Residuals Are Monitored Monthly, Including Field Techs Monitoring Of Chemical Quantities And Chemical Injection Pump Operations On A Monthly Basis.
Int Other Basis Ind
Yes
Int Corrosion Basis Details
Ut Readings Taken By Divers Indicated No External Corrosion And/or Damage. These Results Concluded The Leak Cause To Be An Internal Isolated Pinhole.
Int Low Point Pipe Loc Ind
Yes
Int Other Loc Ind
Yes
Corrosion Location Details
The Location Of The Pinhole Leak Was On The 7 O'clock Postion.
Corrosion Inhibitors
Yes
Corrosion Lining
No
Cleaning Dewatering
Yes
Corrosion Coupons
Yes
Collected Data Ind
No
Has Hydrtst Conduc Before Ind
No
Non Destructive Exam Ind
No
Preparer Name
J***** L****
Preparer Title
Regulatory Compliance Specialist
Preparer Email
J***********@w*******.com
Preparer Telephone
7132152995
Preparer Fax
7132152222
Authorizer Name
M**** S****
Authorizer Title
Manager Safety Regulatory Compliance
Authorizer Telephone
7132152111
Authorizer Email
M**********@w*******.com
Narrative
11-24-2014 transcontinental's (transco) schriever operations district was contacted by coast guard regarding bubbles that had been sited in the vicinty of transco's facilities (area/block ss 7). The coordinates that were recieved from the coast guard were plotted by the schriever operations team. Transco's 16" & 20" gas gathering pipelines near the suspect leak location were isolated and blown down. Transco's support engineer begins the process of contacting contractor dive teams and equipment to investigate and repair the leak. Once the blow down of the lines was complete the 16" line was identified as the leaking line. 11-28-2014 the dive team begins cleaning the line and initiates the investigation. A ut reading of the leaking line is performed by the dive team. A repair clamp has been installed on the leak 11-30-2014. The line is repressured and back in full service 12-1-2014. The results of the investigation "shown below" determined the most probable cause of the leak on the 16" gas gathering pipeline was due to internal corrosion. The location of the leak on the pipe was at the 7 o'clock position. The ut inspection results showed no external corrosion or damage on the pipeline. A low flow unprocessed & undehydrated gas is transported through the pipeline since 1990. Transco does review every internal corrosion leak and follows it's pocedures to prevent and mitigate these types of enviroment. - this line has been transporting unprocessed and undehydrated gas since 1990 and has been treated since 1990 with corrosion inhibitors & biocides. - samples are collected & residuals are monitored monthly. - field techs monitor the chemical quantities and chemical injection pump operations on a monthly basis. - transco's corrosion engineers and smes review every internal corrosion leak that occur on thier systems and make reccomendations as needed.
| Report Received Date | 2014-12-17 00:00:00 |
|---|---|
| Iyear | 2014 |
| Report Number | 20140138 |
| Supplemental Number | 16579 |
| Report Type | Supplemental Final |
| Operator Id | 19570 PHMSA Enforcement |
| Name | Transcontinental Gas Pipe Line Company |
| Operator Street Address | One Williams Center Md 43-4 |
| Operator City Name | Tulsa |
| Operator State Abbreviation | OK |
| Operator Postal Code | 74172 |
| Local Datetime | 2014-11-24 12:45:00 |
| Location Latitude | 29.1857416 Google Maps OpenStreetMap |
| Location Longitude | 91.1733138 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1101890 NRC Report How to search |
| Nrc Rpt Datetime | 2014-11-24 14:05:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 50 |
| Intentional Release | 3598 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | Yes |
| Shutdown Datetime | 2014-11-24 15:45:00 |
| Restart Datetime | 2014-11-30 15:20:00 |
| Ignite Ind | No |
| Explode Ind | No |
| Incident Identified Datetime | 2014-11-24 12:45:00 |
| On Site Datetime | 2014-11-24 12:45:00 |
| On Off Shore | Offshore |
| Off Water Depth | 9 |
| Off Accident Origin | On The Outer Continental Shelf (Ocs) |
| Off Ocs Area | Ship Shoal |
| Off Ocs Block | 7 |
| 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 Body |
| Pipe Diameter | 16 |
| Pipe Wall Thickness | 0.312 |
| Pipe Smys | 52000 |
| Pipe Specification | Api 5l |
| Pipe Seam Type | Flash Welded |
| Pipe Manufacturer | A.o Smith |
| Pipe Coating Type | Other |
| Pipe Coating Details | Asphalt With 3" Concrete Overlayed. |
| Installation Year | 1959 |
| Manufactured Year | 1959 |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Pinhole |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 418 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 10 |
| Est Cost Intentional Release | 13150 |
| Est Cost Prop Damage | 275000 |
| Est Cost Emergency | 5000 |
| Est Cost Other | 5000 |
| Est Cost Other Details | Labor |
| Prpty | 298160 |
| Accident Psig | 740 |
| Mop Psig | 1440 |
| 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 | 58450 |
| Internal Inspection Ind | No |
| Other Inspection Ind | Yes |
| Internal Inspection Details | Launching And Receiving Pig Traps Are Not Designed To Handle A Smart Pig. |
| Operation Complications Ind | Yes |
| Low Flow Ind | Yes |
| Other Complications Ind | Yes |
| Inspect Comp Details | Low Pressure Unprocessed Gas. |
| Pipeline Function | Offshore Gathering |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | Yes |
| Scada Detection Ind | No |
| Scada Conf Ind | No |
| Accident Identifier | Notification From Emergency Responder |
| 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 leak with minimal pressure loss generated from the leak was undetectable by this method. |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Corrosion Failure |
| Cause Details | Internal Corrosion |
| Internal External | Internal Corrosion |
| Int Visual Exam Results | Not Cut Open |
| Int Other Corrosion Ind | Yes |
| Int Corrosion Type Details | This Pipeline Has Been In Unprocessed And Undehydrated Service Since 1990. This Line Has Been Treated Since 1990 With Corrosion Inhibitors & Biocides. Samples Are Collected & Residuals Are Monitored Monthly, Including Field Techs Monitoring Of Chemical Quantities And Chemical Injection Pump Operations On A Monthly Basis. |
| Int Other Basis Ind | Yes |
| Int Corrosion Basis Details | Ut Readings Taken By Divers Indicated No External Corrosion And/or Damage. These Results Concluded The Leak Cause To Be An Internal Isolated Pinhole. |
| Int Low Point Pipe Loc Ind | Yes |
| Int Other Loc Ind | Yes |
| Corrosion Location Details | The Location Of The Pinhole Leak Was On The 7 O'clock Postion. |
| Corrosion Inhibitors | Yes |
| Corrosion Lining | No |
| Cleaning Dewatering | Yes |
| Corrosion Coupons | Yes |
| Collected Data Ind | No |
| Has Hydrtst Conduc Before Ind | No |
| Non Destructive Exam Ind | No |
| Preparer Name | J***** L**** |
| Preparer Title | Regulatory Compliance Specialist |
| Preparer Email | J***********@w*******.com |
| Preparer Telephone | 7132152995 |
| Preparer Fax | 7132152222 |
| Authorizer Name | M**** S**** |
| Authorizer Title | Manager Safety Regulatory Compliance |
| Authorizer Telephone | 7132152111 |
| Authorizer Email | M**********@w*******.com |
| Narrative | 11-24-2014 transcontinental's (transco) schriever operations district was contacted by coast guard regarding bubbles that had been sited in the vicinty of transco's facilities (area/block ss 7). The coordinates that were recieved from the coast guard were plotted by the schriever operations team. Transco's 16" & 20" gas gathering pipelines near the suspect leak location were isolated and blown down. Transco's support engineer begins the process of contacting contractor dive teams and equipment to investigate and repair the leak. Once the blow down of the lines was complete the 16" line was identified as the leaking line. 11-28-2014 the dive team begins cleaning the line and initiates the investigation. A ut reading of the leaking line is performed by the dive team. A repair clamp has been installed on the leak 11-30-2014. The line is repressured and back in full service 12-1-2014. The results of the investigation "shown below" determined the most probable cause of the leak on the 16" gas gathering pipeline was due to internal corrosion. The location of the leak on the pipe was at the 7 o'clock position. The ut inspection results showed no external corrosion or damage on the pipeline. A low flow unprocessed & undehydrated gas is transported through the pipeline since 1990. Transco does review every internal corrosion leak and follows it's pocedures to prevent and mitigate these types of enviroment. - this line has been transporting unprocessed and undehydrated gas since 1990 and has been treated since 1990 with corrosion inhibitors & biocides. - samples are collected & residuals are monitored monthly. - field techs monitor the chemical quantities and chemical injection pump operations on a monthly basis. - transco's corrosion engineers and smes review every internal corrosion leak that occur on thier systems and make reccomendations as needed. |
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