GTG incident on 2022-07-28 — UT

Operator
Northwest Pipeline Llc
Cause
Other Incident Cause
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$0
Incident datetime
2022-07-28 22:10
Report number
Location
UT
Narrative
On july 28th, 2022 there was an improper sealing of a unit valve at northwest pipeline willard compressor station. Williams operations received a call from skamania county 911 dispatch at 22:10 local time reporting a strong smell of gas from a neighbor near the compressor station. Williams operations personnel immediately responded to the call and arrived on-site at 23:50 local time to assess the situation. While on-site it was discovered that the vent valve on unit one at the compressor station was showing closed on the hmi but was still venting gas. In an effort to stop the gas from venting as quickly as possible operations technicians at the site consulted with pipeline control and the operations supervisor and agreed to issue a start command to unit one. Issuing this start command was found to cause all valves to position themselves correctly, thus stopping the gas from venting to the atmosphere. Shortly after, a stop command was subsequently issued to the same unit, with operations noting that all valves also correctly positioned themselves again. It was noted by pipeline control that this unit would not be needed for the rest of the night, so unit one was left off and unavailable until the next day. Once the unit had been shut down and no additional venting was confirmed, operations contacted the security operations center (soc) at 01:40 local time. At this time, the soc ran gas loss estimation calculations and was able to confirm discovery that the 3mmscf release threshold was reached. Shortly after, at 01:52, after a conversation between the soc and pipeline safety, it was determined to report the incident to the nrc. Operations personnel that responded to the incident went home to rest before arriving on-site the next morning to continue the troubleshooting process. The following morning operations and tech services employees worked to troubleshoot the valve position indicators and were not able to recreate the problem that caused unit one suction valve to remain cracked during a remote stop. To better alert operation personnel of a similar incident occurring, pipeline control placed a temporary pressure alarm to monitor case pressure. Over the course of the following weeks, operations personnel attempted to recreate the issue to better understand what caused the initial incident. Multiple efforts to recreate the issue were unsuccessful and a full root-cause investigation has since taken place. The findings of the investigation revealed that the unit 1 blowdown valve had been leaking 12 hours prior to pipeline control receiving notification from the emergency dispatch. The investigation into why the blowdown valve failed to seal found that there was likely some debris in the seat of the unit valve that caused it to not seal properly. It's believed that these debris may have originated from pipeline cleaning / pigging efforts as part of a series of hydrotest projects that had recently occurred in the area. It was also found that power turbine percent speed and suction/discharge pressures were not utilized to show indication of a potential issue with the compressor. These items weren't specifically reviewed at the time as there were no alarms given to pipeline control. To prevent this from happening in the future, williams is implementing a continuous venting unit alarm within scada, station, and unit control systems.
Detailed record list
Report Received Date
2022-08-25 00:00:00
Iyear
2022
Report Number
20220090
Supplemental Number
37424
Report Type
Supplemental Final
Operator Id
Name
Northwest Pipeline Llc
Operator Street Address
295 Chipeta Way
Operator City Name
Salt Lake City
Operator State Abbreviation
UT
Operator Postal Code
84108
Local Datetime
2022-07-28 12:41:00
Time Zone
Pacific
Daylight Savings Ind
Yes
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2022-07-29 01:52:00
Additional Nrc Report Numbers
1342995
Commodity Released Type
Natural Gas
Unintentional Release
52000
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Routine Shutdown
Ignite Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2022-07-28 22:10:00
On Site Datetime
2022-07-28 23:50:00
On Off Shore
Onshore
Onshore State Abbreviation
Wa
Onshore Postal Code
98605
Onshore City Name
Cook
Onshore County Name
Klickitat
Designated Location
Milepost
Designated Name
1175.17
Pipe Fac Name
Nwp Willard Compressor Station
Segment Name
Willard Compressor Station
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 Compressor Station Equipment And Piping
Item Involved
Compressor
Installation Year
1992
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Seal Or Packing
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
620
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
466960
Est Cost Intentional Release
0
Est Cost Prop Damage
0
Est Cost Emergency
2000
Est Cost Other
15000
Est Cost Other Details
Other Costs Involve Rca Investigation Team And Operations Troubleshooting Effort
Gas Cost In Mcf
8.98
Prpty
483960
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
360
Gas Flow In Pipe In Mcf
242000
Mop Psig
809
Mop Cfr Section
192.619(A)(2)
Maop Established Date
1992-08-03 00:00:00
Maop Reversal Flow Ind
Bi-Directional
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized 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 Emergency Responder
Investigation Status
Yes, specify investigation result(s): (select all that apply)
Invest Schedule Ind
Yes
Invest No Controller Ind
Yes
Invest Other Ind
Yes
Invest Other Ind Details
Contributing Findings Include: - Loading Or Suction Valve Failed To Close Fully. -Power Turbine Percent Speed And Suction / Discharge Pressures Were Indicated On Local Hmi And Observable By Gas Control But Were Not Specifically Reviewed.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Other Incident Cause
Cause Details
Miscellaneous
Other Type
Miscellaneous
Misc Details
The Investigation Team Concluded That There Was Likely Debris That Found Their Way Into The Seat Of The Valve. This Debris Could've Originated From Hydrotest Projects That Had Been Taking Place Near The Compressor Station Earlier This Year. This Remains The Most Likely Cause, And Is Still Seen As A "hypothetical" Cause As No Debris Were Found After Further Investigation.
Preparer Name
T***** J*****
Preparer Title
Pipeline Safety Engineer
Preparer Email
T************@w*******.com
Preparer Telephone
2813828869
Authorizer Name
J*** B***
Authorizer Title
Pipeline Safety Manager
Authorizer Telephone
3373179145
Authorizer Email
J********@w*******.com
Narrative
On july 28th, 2022 there was an improper sealing of a unit valve at northwest pipeline willard compressor station. Williams operations received a call from skamania county 911 dispatch at 22:10 local time reporting a strong smell of gas from a neighbor near the compressor station. Williams operations personnel immediately responded to the call and arrived on-site at 23:50 local time to assess the situation. While on-site it was discovered that the vent valve on unit one at the compressor station was showing closed on the hmi but was still venting gas. In an effort to stop the gas from venting as quickly as possible operations technicians at the site consulted with pipeline control and the operations supervisor and agreed to issue a start command to unit one. Issuing this start command was found to cause all valves to position themselves correctly, thus stopping the gas from venting to the atmosphere. Shortly after, a stop command was subsequently issued to the same unit, with operations noting that all valves also correctly positioned themselves again. It was noted by pipeline control that this unit would not be needed for the rest of the night, so unit one was left off and unavailable until the next day. Once the unit had been shut down and no additional venting was confirmed, operations contacted the security operations center (soc) at 01:40 local time. At this time, the soc ran gas loss estimation calculations and was able to confirm discovery that the 3mmscf release threshold was reached. Shortly after, at 01:52, after a conversation between the soc and pipeline safety, it was determined to report the incident to the nrc. Operations personnel that responded to the incident went home to rest before arriving on-site the next morning to continue the troubleshooting process. The following morning operations and tech services employees worked to troubleshoot the valve position indicators and were not able to recreate the problem that caused unit one suction valve to remain cracked during a remote stop. To better alert operation personnel of a similar incident occurring, pipeline control placed a temporary pressure alarm to monitor case pressure. Over the course of the following weeks, operations personnel attempted to recreate the issue to better understand what caused the initial incident. Multiple efforts to recreate the issue were unsuccessful and a full root-cause investigation has since taken place. The findings of the investigation revealed that the unit 1 blowdown valve had been leaking 12 hours prior to pipeline control receiving notification from the emergency dispatch. The investigation into why the blowdown valve failed to seal found that there was likely some debris in the seat of the unit valve that caused it to not seal properly. It's believed that these debris may have originated from pipeline cleaning / pigging efforts as part of a series of hydrotest projects that had recently occurred in the area. It was also found that power turbine percent speed and suction/discharge pressures were not utilized to show indication of a potential issue with the compressor. These items weren't specifically reviewed at the time as there were no alarms given to pipeline control. To prevent this from happening in the future, williams is implementing a continuous venting unit alarm within scada, station, and unit control systems.
Report Received Date 2022-08-25 00:00:00
Iyear 2022
Report Number 20220090
Supplemental Number 37424
Report Type Supplemental Final
Operator Id 13845 PHMSA Enforcement
Name Northwest Pipeline Llc
Operator Street Address 295 Chipeta Way
Operator City Name Salt Lake City
Operator State Abbreviation UT
Operator Postal Code 84108
Local Datetime 2022-07-28 12:41:00
Time Zone Pacific
Daylight Savings Ind Yes
Location Latitude 45.777747 Google Maps OpenStreetMap
Location Longitude -121.626114 Google Maps OpenStreetMap
Nrc Rpt Num 1342913 NRC Report How to search
Nrc Rpt Datetime 2022-07-29 01:52:00
Additional Nrc Report Numbers 1342995
Commodity Released Type Natural Gas
Unintentional Release 52000
Intentional Release 0
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Status When Identified Routine Shutdown
Ignite Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2022-07-28 22:10:00
On Site Datetime 2022-07-28 23:50:00
On Off Shore Onshore
Onshore State Abbreviation Wa
Onshore Postal Code 98605
Onshore City Name Cook
Onshore County Name Klickitat
Designated Location Milepost
Designated Name 1175.17
Pipe Fac Name Nwp Willard Compressor Station
Segment Name Willard Compressor Station
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 Compressor Station Equipment And Piping
Item Involved Compressor
Installation Year 1992
Manufactured Year Unknown
Material Involved Carbon Steel
Release Type Leak
Leak Type Seal Or Packing
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 620
Heat Damage Ind No
Non Heat Damage Ind No
Did Occur In Mca Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 466960
Est Cost Intentional Release 0
Est Cost Prop Damage 0
Est Cost Emergency 2000
Est Cost Other 15000
Est Cost Other Details Other Costs Involve Rca Investigation Team And Operations Troubleshooting Effort
Gas Cost In Mcf 8.98
Prpty 483960
Num Persons Hosp Not Ovnght 0
Num Injured Treated By Emt 0
Num Resident Building Affctd 0
Num Business Building Affctd 0
Wildlife Impact Ind No
Accident Psig 360
Gas Flow In Pipe In Mcf 242000
Mop Psig 809
Mop Cfr Section 192.619(A)(2) View CFR 49 §192
Maop Established Date 1992-08-03 00:00:00
Maop Reversal Flow Ind Bi-Directional
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Gas Required Odorized 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 Emergency Responder
Investigation Status Yes, specify investigation result(s): (select all that apply)
Invest Schedule Ind Yes
Invest No Controller Ind Yes
Invest Other Ind Yes
Invest Other Ind Details Contributing Findings Include: - Loading Or Suction Valve Failed To Close Fully. -Power Turbine Percent Speed And Suction / Discharge Pressures Were Indicated On Local Hmi And Observable By Gas Control But Were Not Specifically Reviewed.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Other Incident Cause
Cause Details Miscellaneous
Other Type Miscellaneous
Misc Details The Investigation Team Concluded That There Was Likely Debris That Found Their Way Into The Seat Of The Valve. This Debris Could've Originated From Hydrotest Projects That Had Been Taking Place Near The Compressor Station Earlier This Year. This Remains The Most Likely Cause, And Is Still Seen As A "hypothetical" Cause As No Debris Were Found After Further Investigation.
Preparer Name T***** J*****
Preparer Title Pipeline Safety Engineer
Preparer Email T************@w*******.com
Preparer Telephone 2813828869
Authorizer Name J*** B***
Authorizer Title Pipeline Safety Manager
Authorizer Telephone 3373179145
Authorizer Email J********@w*******.com
Narrative On july 28th, 2022 there was an improper sealing of a unit valve at northwest pipeline willard compressor station. Williams operations received a call from skamania county 911 dispatch at 22:10 local time reporting a strong smell of gas from a neighbor near the compressor station. Williams operations personnel immediately responded to the call and arrived on-site at 23:50 local time to assess the situation. While on-site it was discovered that the vent valve on unit one at the compressor station was showing closed on the hmi but was still venting gas. In an effort to stop the gas from venting as quickly as possible operations technicians at the site consulted with pipeline control and the operations supervisor and agreed to issue a start command to unit one. Issuing this start command was found to cause all valves to position themselves correctly, thus stopping the gas from venting to the atmosphere. Shortly after, a stop command was subsequently issued to the same unit, with operations noting that all valves also correctly positioned themselves again. It was noted by pipeline control that this unit would not be needed for the rest of the night, so unit one was left off and unavailable until the next day. Once the unit had been shut down and no additional venting was confirmed, operations contacted the security operations center (soc) at 01:40 local time. At this time, the soc ran gas loss estimation calculations and was able to confirm discovery that the 3mmscf release threshold was reached. Shortly after, at 01:52, after a conversation between the soc and pipeline safety, it was determined to report the incident to the nrc. Operations personnel that responded to the incident went home to rest before arriving on-site the next morning to continue the troubleshooting process. The following morning operations and tech services employees worked to troubleshoot the valve position indicators and were not able to recreate the problem that caused unit one suction valve to remain cracked during a remote stop. To better alert operation personnel of a similar incident occurring, pipeline control placed a temporary pressure alarm to monitor case pressure. Over the course of the following weeks, operations personnel attempted to recreate the issue to better understand what caused the initial incident. Multiple efforts to recreate the issue were unsuccessful and a full root-cause investigation has since taken place. The findings of the investigation revealed that the unit 1 blowdown valve had been leaking 12 hours prior to pipeline control receiving notification from the emergency dispatch. The investigation into why the blowdown valve failed to seal found that there was likely some debris in the seat of the unit valve that caused it to not seal properly. It's believed that these debris may have originated from pipeline cleaning / pigging efforts as part of a series of hydrotest projects that had recently occurred in the area. It was also found that power turbine percent speed and suction/discharge pressures were not utilized to show indication of a potential issue with the compressor. These items weren't specifically reviewed at the time as there were no alarms given to pipeline control. To prevent this from happening in the future, williams is implementing a continuous venting unit alarm within scada, station, and unit control systems.

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