Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2011-02-18 — TX
Operator
Centerpoint Energy Gas Transmission
Cause
Other Incident Cause
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$113,789
Incident datetime
2011-02-18 20:48
Report number
Location
TX
Narrative
Cegt line bt-1-as leak 02/18/2011 on 2/18/2011 at 20:00 the public reported a possible leak to southern gas operations (sgo). Sgo dispatched an employee to investigate and at 20:15 reported they had found a leak on cegt's row for the bt-1 system. At 20:17 sgo contacted the cegt pipeline team to advise them of the leak. A team member was sent to the leak location to verify the leak. At 20:48 the leak was confirmed to be on cegt's line bt-1-as and reported to system control. It was determined to be a minor leak. Cegt began working with sgo to understand the customer load. Employees were stationed at the leak to man it until the leak was stopped. At 21:15 cegt area management notified system control that they had generated a plan to lower the pressure on a 16 mile section of bt1-as from 870# to 400#. At 22:00 personnel were dispatched to begin moving all customers possible to an alternative cegt pipeline. On 2/19/2011 at 01:30 crews began blowing down and the pressure was lowered to 400# by 03:30. Personnel stayed at each mlv location monitoring pressures (12 hour rotation for duration of incident). On 2/21/2011 at 11:00 excavation began to install a stopple fitting 3.5 miles north of the leak. On 2/22/2011 at 11:00 the stoppall was completed and cegt team personnel blew down a 6.6 mile pipeline section containing the leak. At 15:00 the leak was exposed enough to determine a cause, approximately a 4" crack in the pipe. On 2/23/2011 at 16:30 pipe was delivered and weld caps were installed. At 19:00 a 4 hour hydro test began, it ended near 24:00. On 2/24/2011 at 07:00 contractors began to remove the pipe to be replaced. At 10:00 the crew began installing the new section of pipe. On 2/25/2011 crews completed the replacement and at 17:00 began purging. The purge was completed at 19:30. On 2/26/2011 at 07:30 the crew began backfilling at leak excavation, recoating at stopple fitting location and then reloaded the line. At 16:00 the system was returned to normal operations. The section of pipe removed was sent to kiefner & associates for metallurgical analysis. It was determined that the final failure mode was ductile overload of the remaining ligament beneath the scc. The remaining ligament was observed to be approximately 50% of the pipe wall thickness minimum. The fact that these cracks were critical at this size indicates the presence of a relatively high axial load. The findings are as follows:
Detailed record list
Report Received Date
2011-03-04 00:00:00
Iyear
2011
Report Number
20110027
Supplemental Number
15323
Report Type
Supplemental Final
Operator Id
Name
Centerpoint Energy Gas Transmission
Operator Street Address
1300 Main Street
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Local Datetime
2011-02-18 20:48:00
Location Latitude
34.54358
Location Longitude
-92.95402
Nrc Rpt Num
967943
Nrc Rpt Datetime
2011-02-18 23:06:00
Commodity Released Type
Natural Gas
Unintentional Release
770
Intentional Release
5256
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2011-02-22 11:00:00
Restart Datetime
2011-02-25 19:30:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2011-02-18 20:48:00
On Site Datetime
2011-02-18 20:48:00
On Off Shore
Onshore
Onshore State Abbreviation
Ar
Onshore Postal Code
71901
Onshore City Name
Hot Springs
Onshore County Name
Garland
Designated Location
Survey Station No.
Designated Name
878+53
Pipe Fac Name
Cegt Line Bt-1as
Segment Name
Sg17539
Federal
No
Location Type
Pipeline Right-Of-Way
Incident Area Type
Underground
Incident Area Subtype
Under Soil
Depth Of Cover
49
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Pipeline, Including Valve Sites
Item Involved
Pipe
Pipe Type
Pipe Body
Pipe Diameter
16
Pipe Wall Thickness
0.25
Pipe Smys
46000
Pipe Specification
X-46
Pipe Seam Type
Longitudinal Erw - Unknown Frequency
Pipe Manufacturer
Unknown
Pipe Coating Type
Field Applied Epoxy
Installation Year
1963
Manufactured Year
1959
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Crack
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
349
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
2957
Est Cost Intentional Release
18664
Est Cost Prop Damage
113789
Est Cost Emergency
6525
Est Cost Other
10000
Est Cost Other Details
Lab Analysis
Prpty
151935
Accident Psig
864
Mop Psig
1000
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
34848
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
Notification From Public
Investigation Status
Yes, specify investigation result(s): (select all that apply)
Invest No Control Room Ind
Yes
Invest No Controller Ind
Yes
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Other Incident Cause
Cause Details
Miscellaneous
Other Type
Miscellaneous
Misc Details
Multiple Factors Are Believed To Have Contributed To The Cause Of The Circumferential Crack. External Corrosion Reduced The Wall Thickness By Approximately 50% At The Point Of Failure, The Pipe May Not Have Been Properly Supported Prior To Restoring Fill And The Pipe Was Subjected To Relatively High Axial Loads.
Preparer Name
J**** C****
Preparer Title
Dot Waiver Specialist
Preparer Email
J**********@c****************.com
Preparer Telephone
318 429-3664
Preparer Fax
318 429-3927
Authorizer Name
J***** C*****
Authorizer Title
Dot Compliance Manager
Authorizer Telephone
318 429-3660
Authorizer Email
J************@c****************.com
Narrative
Cegt line bt-1-as leak 02/18/2011 on 2/18/2011 at 20:00 the public reported a possible leak to southern gas operations (sgo). Sgo dispatched an employee to investigate and at 20:15 reported they had found a leak on cegt's row for the bt-1 system. At 20:17 sgo contacted the cegt pipeline team to advise them of the leak. A team member was sent to the leak location to verify the leak. At 20:48 the leak was confirmed to be on cegt's line bt-1-as and reported to system control. It was determined to be a minor leak. Cegt began working with sgo to understand the customer load. Employees were stationed at the leak to man it until the leak was stopped. At 21:15 cegt area management notified system control that they had generated a plan to lower the pressure on a 16 mile section of bt1-as from 870# to 400#. At 22:00 personnel were dispatched to begin moving all customers possible to an alternative cegt pipeline. On 2/19/2011 at 01:30 crews began blowing down and the pressure was lowered to 400# by 03:30. Personnel stayed at each mlv location monitoring pressures (12 hour rotation for duration of incident). On 2/21/2011 at 11:00 excavation began to install a stopple fitting 3.5 miles north of the leak. On 2/22/2011 at 11:00 the stoppall was completed and cegt team personnel blew down a 6.6 mile pipeline section containing the leak. At 15:00 the leak was exposed enough to determine a cause, approximately a 4" crack in the pipe. On 2/23/2011 at 16:30 pipe was delivered and weld caps were installed. At 19:00 a 4 hour hydro test began, it ended near 24:00. On 2/24/2011 at 07:00 contractors began to remove the pipe to be replaced. At 10:00 the crew began installing the new section of pipe. On 2/25/2011 crews completed the replacement and at 17:00 began purging. The purge was completed at 19:30. On 2/26/2011 at 07:30 the crew began backfilling at leak excavation, recoating at stopple fitting location and then reloaded the line. At 16:00 the system was returned to normal operations. The section of pipe removed was sent to kiefner & associates for metallurgical analysis. It was determined that the final failure mode was ductile overload of the remaining ligament beneath the scc. The remaining ligament was observed to be approximately 50% of the pipe wall thickness minimum. The fact that these cracks were critical at this size indicates the presence of a relatively high axial load. The findings are as follows:
| Report Received Date | 2011-03-04 00:00:00 |
|---|---|
| Iyear | 2011 |
| Report Number | 20110027 |
| Supplemental Number | 15323 |
| Report Type | Supplemental Final |
| Operator Id | 602 PHMSA Enforcement |
| Name | Centerpoint Energy Gas Transmission |
| Operator Street Address | 1300 Main Street |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77002 |
| Local Datetime | 2011-02-18 20:48:00 |
| Location Latitude | 34.54358 Google Maps OpenStreetMap |
| Location Longitude | -92.95402 Google Maps OpenStreetMap |
| Nrc Rpt Num | 967943 NRC Report How to search |
| Nrc Rpt Datetime | 2011-02-18 23:06:00 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 770 |
| Intentional Release | 5256 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Shutdown Due Accident Ind | Yes |
| Shutdown Datetime | 2011-02-22 11:00:00 |
| Restart Datetime | 2011-02-25 19:30:00 |
| Ignite Ind | No |
| Explode Ind | No |
| Num Pub Evacuated | 0 |
| Incident Identified Datetime | 2011-02-18 20:48:00 |
| On Site Datetime | 2011-02-18 20:48:00 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ar |
| Onshore Postal Code | 71901 |
| Onshore City Name | Hot Springs |
| Onshore County Name | Garland |
| Designated Location | Survey Station No. |
| Designated Name | 878+53 |
| Pipe Fac Name | Cegt Line Bt-1as |
| Segment Name | Sg17539 |
| Federal | No |
| Location Type | Pipeline Right-Of-Way |
| Incident Area Type | Underground |
| Incident Area Subtype | Under Soil |
| Depth Of Cover | 49 |
| Crossing | No |
| Pipe Facility Type | Interstate |
| System Part Involved | Onshore Pipeline, Including Valve Sites |
| Item Involved | Pipe |
| Pipe Type | Pipe Body |
| Pipe Diameter | 16 |
| Pipe Wall Thickness | 0.25 |
| Pipe Smys | 46000 |
| Pipe Specification | X-46 |
| Pipe Seam Type | Longitudinal Erw - Unknown Frequency |
| Pipe Manufacturer | Unknown |
| Pipe Coating Type | Field Applied Epoxy |
| Installation Year | 1963 |
| Manufactured Year | 1959 |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Crack |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 349 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Hca Fatalities Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 2957 |
| Est Cost Intentional Release | 18664 |
| Est Cost Prop Damage | 113789 |
| Est Cost Emergency | 6525 |
| Est Cost Other | 10000 |
| Est Cost Other Details | Lab Analysis |
| Prpty | 151935 |
| Accident Psig | 864 |
| Mop Psig | 1000 |
| 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 | 34848 |
| 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 | Notification From Public |
| Investigation Status | Yes, specify investigation result(s): (select all that apply) |
| Invest No Control Room Ind | Yes |
| Invest No Controller Ind | Yes |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | No |
| Cause | Other Incident Cause |
| Cause Details | Miscellaneous |
| Other Type | Miscellaneous |
| Misc Details | Multiple Factors Are Believed To Have Contributed To The Cause Of The Circumferential Crack. External Corrosion Reduced The Wall Thickness By Approximately 50% At The Point Of Failure, The Pipe May Not Have Been Properly Supported Prior To Restoring Fill And The Pipe Was Subjected To Relatively High Axial Loads. |
| Preparer Name | J**** C**** |
| Preparer Title | Dot Waiver Specialist |
| Preparer Email | J**********@c****************.com |
| Preparer Telephone | 318 429-3664 |
| Preparer Fax | 318 429-3927 |
| Authorizer Name | J***** C***** |
| Authorizer Title | Dot Compliance Manager |
| Authorizer Telephone | 318 429-3660 |
| Authorizer Email | J************@c****************.com |
| Narrative | Cegt line bt-1-as leak 02/18/2011 on 2/18/2011 at 20:00 the public reported a possible leak to southern gas operations (sgo). Sgo dispatched an employee to investigate and at 20:15 reported they had found a leak on cegt's row for the bt-1 system. At 20:17 sgo contacted the cegt pipeline team to advise them of the leak. A team member was sent to the leak location to verify the leak. At 20:48 the leak was confirmed to be on cegt's line bt-1-as and reported to system control. It was determined to be a minor leak. Cegt began working with sgo to understand the customer load. Employees were stationed at the leak to man it until the leak was stopped. At 21:15 cegt area management notified system control that they had generated a plan to lower the pressure on a 16 mile section of bt1-as from 870# to 400#. At 22:00 personnel were dispatched to begin moving all customers possible to an alternative cegt pipeline. On 2/19/2011 at 01:30 crews began blowing down and the pressure was lowered to 400# by 03:30. Personnel stayed at each mlv location monitoring pressures (12 hour rotation for duration of incident). On 2/21/2011 at 11:00 excavation began to install a stopple fitting 3.5 miles north of the leak. On 2/22/2011 at 11:00 the stoppall was completed and cegt team personnel blew down a 6.6 mile pipeline section containing the leak. At 15:00 the leak was exposed enough to determine a cause, approximately a 4" crack in the pipe. On 2/23/2011 at 16:30 pipe was delivered and weld caps were installed. At 19:00 a 4 hour hydro test began, it ended near 24:00. On 2/24/2011 at 07:00 contractors began to remove the pipe to be replaced. At 10:00 the crew began installing the new section of pipe. On 2/25/2011 crews completed the replacement and at 17:00 began purging. The purge was completed at 19:30. On 2/26/2011 at 07:30 the crew began backfilling at leak excavation, recoating at stopple fitting location and then reloaded the line. At 16:00 the system was returned to normal operations. The section of pipe removed was sent to kiefner & associates for metallurgical analysis. It was determined that the final failure mode was ductile overload of the remaining ligament beneath the scc. The remaining ligament was observed to be approximately 50% of the pipe wall thickness minimum. The fact that these cracks were critical at this size indicates the presence of a relatively high axial load. The findings are as follows: |
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