GTG incident on 2019-01-17 — TX

Operator
Colorado Interstate Gas Co
Cause
Material Failure Of Pipe Or Weld
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$5,000
Incident datetime
2019-01-17 23:55
Report number
Location
TX
Narrative
On january 17, 2019 at approximately 11:55 pm local time, colorado interstate gas (cig) gas control received a telephone call from a third-party oil and gas operator reporting a sound of gas releasing from our pipeline facility at the l250a pig launcher and pig receiving facility in weld county, colorado. Upon receiving the third-party report, gas control called the cig area supervisor and dispatched him to the location. He arrived on site at 1:18 am local time on january 18, 2019 and verified that the gas leak was in fact on the cig l250 pipeline pig trap facility. At 1:50 am local time on january 18, 2019, cig initiated an internal emergency-response-line (erl) telephone call to discuss the available information regarding the gas leak to determine whether discovery of a reportable event occurred. Since the 250a segment impacted by the leak could not be immediately isolated until alternative gas supplies for cig's customers served from that segment could be arranged, cig decided to assume the release volumes would exceed the reportable threshold and decided to notify the national response center (nrc) of the event prior to establishing the actual volumes released. It was not until the affected segment containing the leak could be isolated at 4:17 am on january 18, 2019, that cig was able to estimate the actual release volume. During the initial investigation, cig calculated the total release volume (3,282 mcf) and determined it had met the reporting requirement for the event at 3:55 am on january 18, 2019. The nrc was notified at 2:04 am local time on january 18, 2019 (nrc no. 1235460) of the gas release with an estimate to be greater than 3,000 mcf and resulting in a reportable event. The nrc logged receipt of the report at 2:09 am local time. A courtesy notification to the PHMSA incident investigation team was provided at 2:38 am local time that day. At 3:06 pm local time on january 18, 2019, all repairs to the facilities were complete and returned to service. At 3:54 pm local time on january 18, 2019, a 48-hour update report was called into the nrc (report no. 1235523) providing the total volume of the release (3,282 mcf) with confirmation that there were no customer impacts due to the incident. The nrc logged the receipt of the report at 14:02 local time. The 1' blow-off valve assembly that failed was sent for a complete metallurgical analysis to determine the root cause of the failure. From the metallurgical analysis, it was determined the root cause of the butt weld failure was caused by high-cycle, low nominal stress, unidirectional-bending fatigue. Operations field personnel observed that the 1' blow-off valve assembly was found approximately 25 feet from the welded coupling located on the 250a pipeline following the event. The threaded nipple end of the assembly was located approximately 6-12 inches from the rest of the vent valve assembly. The valve was found in the closed position. Based on these observations, it was concluded that the welded end failed first and the threaded nipple separated from the vent valve after the entire 1' blow-off valve assembly was ejected and impacted with the ground. The metallurgical analysis did not identify any material composition deficiencies of the assembly. In addition no evidence of excessive torque was identified. Cig concluded the root cause of the threaded-end of the nipple blow-off valve assembly failure resulted from the assembly impacting the ground surface. The root cause of the weld failure is associated with a vibration caused from an 8-inch flow control valve at the regulator station at gate 6. Cig finalized a vibration study on april 24, 2019. Results of the study identified facility modifications will be necessary to help reduce vibration and until these changes can be completed, cig will implement operating changes as needed to help lower vibration levels.
Detailed record list
Report Received Date
2019-02-15 00:00:00
Iyear
2019
Report Number
20190015
Supplemental Number
32062
Report Type
Supplemental Final
Operator Id
Name
Colorado Interstate Gas Co
Operator Street Address
1001 Louisiana St, Suite 1000
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Local Datetime
2019-01-18 03:55:00
Location Latitude
Location Longitude
-104.6089491
Nrc Rpt Num
Nrc Rpt Datetime
2019-01-18 02:04:00
Commodity Released Type
Natural Gas
Unintentional Release
3282
Intentional Release
96.1
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2019-01-18 04:17:00
Restart Datetime
2019-01-18 15:06:00
Ignite Ind
No
Explode Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2019-01-17 23:55:00
On Site Datetime
2019-01-18 01:18:00
On Off Shore
Onshore
Onshore State Abbreviation
Co
Onshore Postal Code
80642
Onshore City Name
Not Within A Municipality
Onshore County Name
Weld
Designated Location
Milepost
Designated Name
Mp 63 +563
Pipe Fac Name
L0250a High Plains Main Line
Segment Name
Sta 250-A Hudson
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Regulator/metering Station Equipment And Piping
Item Involved
Weld/fusion, Including Heat-Affected Zone
Weld Subtype
Other Butt Weld
Installation Year
2013
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Other
Leak Type Other
Weld Failure.
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
717
Heat Damage Ind
No
Non Heat Damage Ind
No
Hca Fatalities Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
11516
Est Cost Intentional Release
337
Est Cost Prop Damage
5000
Est Cost Emergency
500
Est Cost Other
700
Est Cost Other Details
Metallurgical Laboratory Analytical Cost.
Prpty
18053
Accident Psig
817
Mop Psig
1200
Mop Cfr Section
192.619(A)(2)
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction 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
Other
Accident Details
Notification From A 3rd-Party Oil And Gas Operator Working Near The Location.
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
No controller actions or control room issues were determined to be a cause or contributing factor to the incident.
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
Metallurgical Ind
Yes
Fatigue Vibr Related
Yes
Failure Subtype
Mechanical Vibration
Pwf Additional Other Ind
Yes
Additional Other Details
High-Cycle, Low Stress, Unidirectional Bending Fatigue.
Collected Data Ind
No
Has Hydrtst Conduc Before Ind
Yes
Direct Asmnt Conducted
No
Non Destructive Exam Ind
No
Preparer Name
S****** R* D****
Preparer Title
Engineer - Codes And Standards
Preparer Email
S************@k***********.com
Preparer Telephone
(719) 329-5633
Authorizer Name
J**** A* H********
Authorizer Title
Director Engineering - Codes And Standards
Authorizer Telephone
713 369-9443
Authorizer Email
J**************@k***********.com
Narrative
On january 17, 2019 at approximately 11:55 pm local time, colorado interstate gas (cig) gas control received a telephone call from a third-party oil and gas operator reporting a sound of gas releasing from our pipeline facility at the l250a pig launcher and pig receiving facility in weld county, colorado. Upon receiving the third-party report, gas control called the cig area supervisor and dispatched him to the location. He arrived on site at 1:18 am local time on january 18, 2019 and verified that the gas leak was in fact on the cig l250 pipeline pig trap facility. At 1:50 am local time on january 18, 2019, cig initiated an internal emergency-response-line (erl) telephone call to discuss the available information regarding the gas leak to determine whether discovery of a reportable event occurred. Since the 250a segment impacted by the leak could not be immediately isolated until alternative gas supplies for cig's customers served from that segment could be arranged, cig decided to assume the release volumes would exceed the reportable threshold and decided to notify the national response center (nrc) of the event prior to establishing the actual volumes released. It was not until the affected segment containing the leak could be isolated at 4:17 am on january 18, 2019, that cig was able to estimate the actual release volume. During the initial investigation, cig calculated the total release volume (3,282 mcf) and determined it had met the reporting requirement for the event at 3:55 am on january 18, 2019. The nrc was notified at 2:04 am local time on january 18, 2019 (nrc no. 1235460) of the gas release with an estimate to be greater than 3,000 mcf and resulting in a reportable event. The nrc logged receipt of the report at 2:09 am local time. A courtesy notification to the PHMSA incident investigation team was provided at 2:38 am local time that day. At 3:06 pm local time on january 18, 2019, all repairs to the facilities were complete and returned to service. At 3:54 pm local time on january 18, 2019, a 48-hour update report was called into the nrc (report no. 1235523) providing the total volume of the release (3,282 mcf) with confirmation that there were no customer impacts due to the incident. The nrc logged the receipt of the report at 14:02 local time. The 1' blow-off valve assembly that failed was sent for a complete metallurgical analysis to determine the root cause of the failure. From the metallurgical analysis, it was determined the root cause of the butt weld failure was caused by high-cycle, low nominal stress, unidirectional-bending fatigue. Operations field personnel observed that the 1' blow-off valve assembly was found approximately 25 feet from the welded coupling located on the 250a pipeline following the event. The threaded nipple end of the assembly was located approximately 6-12 inches from the rest of the vent valve assembly. The valve was found in the closed position. Based on these observations, it was concluded that the welded end failed first and the threaded nipple separated from the vent valve after the entire 1' blow-off valve assembly was ejected and impacted with the ground. The metallurgical analysis did not identify any material composition deficiencies of the assembly. In addition no evidence of excessive torque was identified. Cig concluded the root cause of the threaded-end of the nipple blow-off valve assembly failure resulted from the assembly impacting the ground surface. The root cause of the weld failure is associated with a vibration caused from an 8-inch flow control valve at the regulator station at gate 6. Cig finalized a vibration study on april 24, 2019. Results of the study identified facility modifications will be necessary to help reduce vibration and until these changes can be completed, cig will implement operating changes as needed to help lower vibration levels.
Report Received Date 2019-02-15 00:00:00
Iyear 2019
Report Number 20190015
Supplemental Number 32062
Report Type Supplemental Final
Operator Id 2564 PHMSA Enforcement
Name Colorado Interstate Gas Co
Operator Street Address 1001 Louisiana St, Suite 1000
Operator City Name Houston
Operator State Abbreviation TX
Operator Postal Code 77002
Local Datetime 2019-01-18 03:55:00
Location Latitude 40.117346 Google Maps OpenStreetMap
Location Longitude -104.6089491 Google Maps OpenStreetMap
Nrc Rpt Num 1235460 NRC Report How to search
Nrc Rpt Datetime 2019-01-18 02:04:00
Commodity Released Type Natural Gas
Unintentional Release 3282
Intentional Release 96.1
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Shutdown Due Accident Ind Yes
Shutdown Datetime 2019-01-18 04:17:00
Restart Datetime 2019-01-18 15:06:00
Ignite Ind No
Explode Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2019-01-17 23:55:00
On Site Datetime 2019-01-18 01:18:00
On Off Shore Onshore
Onshore State Abbreviation Co
Onshore Postal Code 80642
Onshore City Name Not Within A Municipality
Onshore County Name Weld
Designated Location Milepost
Designated Name Mp 63 +563
Pipe Fac Name L0250a High Plains Main Line
Segment Name Sta 250-A Hudson
Federal No
Location Type Operator-Controlled Property
Incident Area Type Aboveground
Incident Area Subtype Typical Aboveground Facility Piping Or Appurtenance
Crossing No
Pipe Facility Type Interstate
System Part Involved Onshore Regulator/metering Station Equipment And Piping
Item Involved Weld/fusion, Including Heat-Affected Zone
Weld Subtype Other Butt Weld
Installation Year 2013
Material Involved Carbon Steel
Release Type Leak
Leak Type Other
Leak Type Other Weld Failure.
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 717
Heat Damage Ind No
Non Heat Damage Ind No
Hca Fatalities Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 11516
Est Cost Intentional Release 337
Est Cost Prop Damage 5000
Est Cost Emergency 500
Est Cost Other 700
Est Cost Other Details Metallurgical Laboratory Analytical Cost.
Prpty 18053
Accident Psig 817
Mop Psig 1200
Mop Cfr Section 192.619(A)(2) View CFR 49 §192
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction 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 Other
Accident Details Notification From A 3rd-Party Oil And Gas Operator Working Near The Location.
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 No controller actions or control room issues were determined to be a cause or contributing factor to the incident.
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
Metallurgical Ind Yes
Fatigue Vibr Related Yes
Failure Subtype Mechanical Vibration
Pwf Additional Other Ind Yes
Additional Other Details High-Cycle, Low Stress, Unidirectional Bending Fatigue.
Collected Data Ind No
Has Hydrtst Conduc Before Ind Yes
Direct Asmnt Conducted No
Non Destructive Exam Ind No
Preparer Name S****** R* D****
Preparer Title Engineer - Codes And Standards
Preparer Email S************@k***********.com
Preparer Telephone (719) 329-5633
Authorizer Name J**** A* H********
Authorizer Title Director Engineering - Codes And Standards
Authorizer Telephone 713 369-9443
Authorizer Email J**************@k***********.com
Narrative On january 17, 2019 at approximately 11:55 pm local time, colorado interstate gas (cig) gas control received a telephone call from a third-party oil and gas operator reporting a sound of gas releasing from our pipeline facility at the l250a pig launcher and pig receiving facility in weld county, colorado. Upon receiving the third-party report, gas control called the cig area supervisor and dispatched him to the location. He arrived on site at 1:18 am local time on january 18, 2019 and verified that the gas leak was in fact on the cig l250 pipeline pig trap facility. At 1:50 am local time on january 18, 2019, cig initiated an internal emergency-response-line (erl) telephone call to discuss the available information regarding the gas leak to determine whether discovery of a reportable event occurred. Since the 250a segment impacted by the leak could not be immediately isolated until alternative gas supplies for cig's customers served from that segment could be arranged, cig decided to assume the release volumes would exceed the reportable threshold and decided to notify the national response center (nrc) of the event prior to establishing the actual volumes released. It was not until the affected segment containing the leak could be isolated at 4:17 am on january 18, 2019, that cig was able to estimate the actual release volume. During the initial investigation, cig calculated the total release volume (3,282 mcf) and determined it had met the reporting requirement for the event at 3:55 am on january 18, 2019. The nrc was notified at 2:04 am local time on january 18, 2019 (nrc no. 1235460) of the gas release with an estimate to be greater than 3,000 mcf and resulting in a reportable event. The nrc logged receipt of the report at 2:09 am local time. A courtesy notification to the PHMSA incident investigation team was provided at 2:38 am local time that day. At 3:06 pm local time on january 18, 2019, all repairs to the facilities were complete and returned to service. At 3:54 pm local time on january 18, 2019, a 48-hour update report was called into the nrc (report no. 1235523) providing the total volume of the release (3,282 mcf) with confirmation that there were no customer impacts due to the incident. The nrc logged the receipt of the report at 14:02 local time. The 1' blow-off valve assembly that failed was sent for a complete metallurgical analysis to determine the root cause of the failure. From the metallurgical analysis, it was determined the root cause of the butt weld failure was caused by high-cycle, low nominal stress, unidirectional-bending fatigue. Operations field personnel observed that the 1' blow-off valve assembly was found approximately 25 feet from the welded coupling located on the 250a pipeline following the event. The threaded nipple end of the assembly was located approximately 6-12 inches from the rest of the vent valve assembly. The valve was found in the closed position. Based on these observations, it was concluded that the welded end failed first and the threaded nipple separated from the vent valve after the entire 1' blow-off valve assembly was ejected and impacted with the ground. The metallurgical analysis did not identify any material composition deficiencies of the assembly. In addition no evidence of excessive torque was identified. Cig concluded the root cause of the threaded-end of the nipple blow-off valve assembly failure resulted from the assembly impacting the ground surface. The root cause of the weld failure is associated with a vibration caused from an 8-inch flow control valve at the regulator station at gate 6. Cig finalized a vibration study on april 24, 2019. Results of the study identified facility modifications will be necessary to help reduce vibration and until these changes can be completed, cig will implement operating changes as needed to help lower vibration levels.

All rights reserved. Copyright © by ClearPHMSA