Incident details
Operator, cause, commodity and consequences with raw source fields.
GTG incident on 2024-08-09 — TX
Operator
Central Valley Gas Storage (Cvgs), Llc
Cause
Incorrect Operation
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities
0 injuries
Property damage (nominal)
$62,000
Incident datetime
2024-08-09 00:00 UTC
Report number
Location
TX
Narrative
Well control was temporarily lost during planned maintenance of the c.V.G.S. 1-l (api10: 0401120925), an ungsf gas storage well. At 11:27 am local time on july 11th, 2024, 1,478 feet of 2-3/8' workstring was ejected from the well. Within thirty seconds, the well was controlled and secured by the onsite crews. There were no injuries. Cvgs began its incident response, including notifying the nrc and other regulatory agencies in accordance with cvgs procedures and applicable regulations. Prior to the loss of well control and in accordance with the well work procedure, the well had a retrievable packer installed at 1,507 feet md and a plug set in the packer at 2,424 feet md intended to function as two downhole isolating barriers between the reservoir and the surface. A few elements of the scada monitoring system were purposefully disconnected to isolate hazardous energy and access the well for the planned work, and the scada system for the rest of the facility was operational and functioning. At some time prior to 11:27 am, potentially overnight, pressure built between the barriers installed at 1,507 feet md and 2,424 feet md. At 11:27 am, the workover crews began to release the retrievable packer installed at 1,507 feet md to retrieve it from the well. As the packer was released, the force from the built-up pressure pushed the workstring and retrievable packer out of the wellbore in approximately 3 to 5 seconds. The gas that built up between the two downhole barriers was released. In less than thirty seconds, the onsite crews secured the well with multiple barriers (master valve and blowout preventer elements). The workstring contacted the electronics of an offset well, which shut down in the intended failsafe condition and provided the initial indications of an incident to the control room via the scada system. The surface piping of three offset wells was contacted and then taken out of service until assessments confirmed the damage was only cosmetic. The well work procedure specified to equalize pressure across the retrievable packer installed at 1,507 feet md prior to releasing it. The purpose of this procedural step is to mitigate the possibility of a failure of the isolating barrier installed at 2,424 feet md. The well work crews skipped this step. The failure of the isolating barrier installed at 2,424 feet md is a contributing factor. The estimated release volume was calculated using the well's inflow performance relationship, the reservoir pressure, and the pressure identified at surface during the release. An alternative method results in a lower release volume.
Detailed record list
Report Received Date
2024-08-09 00:00:00
Iyear
2024
Report Number
20240101
Supplemental Number
40084
Report Type
Supplemental Final
Operator Id
32603
Name
Central Valley Gas Storage (Cvgs), Llc
Operator Street Address
919 Milam Street Suite 2425
Operator City Name
Houston
Operator State Abbreviation
TX
Operator Postal Code
77002
Time Zone
Pacific
Daylight Savings Ind
Yes
Location Latitude
39.380226
Location Longitude
-122.03241
Nrc Rpt Num
1404408
Additional Nrc Report Numbers
1404996
Commodity Released Type
Natural Gas
Unintentional Release
34.72
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Idle
Communication State Fed Ind
Yes
Party Initiated Communication
Operator
Ignite Ind
No
Num Pub Evacuated
0
On Off Shore
Onshore
Onshore State Abbreviation
Ca
Onshore Postal Code
95970
Onshore City Name
Not Within A Municipality
Onshore County Name
Colusa
Designated Location
Not Applicable
Pipe Fac Name
Cvgs Storage Facility
Segment Name
Underground Storage Well
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Belowground Storage Or Aboveground Storage Vessel, Including Attached Appurtenance
Crossing
No
Pipe Facility Type
Intrastate
System Part Involved
Belowground Storage, Including Associated Equipment And Piping
Item Involved
Underground Gas Storage Or Cavern
Installation Year
2024
Manufactured Year
Unknown
Material Involved
Carbon Steel
Release Type
Leak
Leak Type
Other
Leak Type Other
Release Of Trapped Pressure
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
209
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
113
Est Cost Intentional Release
0
Est Cost Prop Damage
62000
Est Cost Emergency
45600
Est Cost Other
0
Gas Cost In Mcf
3.26
Prpty
107713
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
824
Gas Flow In Pipe In Mcf
0
Mop Psig
1436
Mop Cfr Section
Other
Mop Cfr Section Details
Derived From Calgem Permitted Injection Gradient In Lieu Of Pressure
Maop Established Date
2010-10-29 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 In Storage Field
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
No
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Accident Identifier
Local Operating Personnel, Including Contractors
Operator Type
Contractor Working For The Operator
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
Primary responsibility for the well work had been handed over from the controller/control room to the well work crews
Employee Drug Test Ind
No
Contractor Drug Test Ind
Yes
Num Contractors Tested
13
Num Contractors Failed
0
Cause
Incorrect Operation
Cause Details
Other Incorrect Operation
Operation Type
Other Incorrect Operation
Operation Details
The Contractor Well Work Crews Failed To Equalize Pressure Across The Retrievable Packer Prior To Releasing It As Required By The Well Work Procedure.
Related Failure Follow Ind
Yes
Category Type
Other Maintenance
Operator Qualification Ind
No
Preparer Name
A** J******
Preparer Title
Director Of Regulatory
Preparer Email
A*******@c*************.com
Preparer Telephone
7134947816
Local Contact Name
J*** B******
Local Contact Email
J*******@c***********.com
Authorizer Name
A** J******
Authorizer Title
Director Of Regulatory
Authorizer Telephone
7134947816
Authorizer Email
A*******@c*************.com
Narrative
Well control was temporarily lost during planned maintenance of the c.V.G.S. 1-l (api10: 0401120925), an ungsf gas storage well. At 11:27 am local time on july 11th, 2024, 1,478 feet of 2-3/8' workstring was ejected from the well. Within thirty seconds, the well was controlled and secured by the onsite crews. There were no injuries. Cvgs began its incident response, including notifying the nrc and other regulatory agencies in accordance with cvgs procedures and applicable regulations. Prior to the loss of well control and in accordance with the well work procedure, the well had a retrievable packer installed at 1,507 feet md and a plug set in the packer at 2,424 feet md intended to function as two downhole isolating barriers between the reservoir and the surface. A few elements of the scada monitoring system were purposefully disconnected to isolate hazardous energy and access the well for the planned work, and the scada system for the rest of the facility was operational and functioning. At some time prior to 11:27 am, potentially overnight, pressure built between the barriers installed at 1,507 feet md and 2,424 feet md. At 11:27 am, the workover crews began to release the retrievable packer installed at 1,507 feet md to retrieve it from the well. As the packer was released, the force from the built-up pressure pushed the workstring and retrievable packer out of the wellbore in approximately 3 to 5 seconds. The gas that built up between the two downhole barriers was released. In less than thirty seconds, the onsite crews secured the well with multiple barriers (master valve and blowout preventer elements). The workstring contacted the electronics of an offset well, which shut down in the intended failsafe condition and provided the initial indications of an incident to the control room via the scada system. The surface piping of three offset wells was contacted and then taken out of service until assessments confirmed the damage was only cosmetic. The well work procedure specified to equalize pressure across the retrievable packer installed at 1,507 feet md prior to releasing it. The purpose of this procedural step is to mitigate the possibility of a failure of the isolating barrier installed at 2,424 feet md. The well work crews skipped this step. The failure of the isolating barrier installed at 2,424 feet md is a contributing factor. The estimated release volume was calculated using the well's inflow performance relationship, the reservoir pressure, and the pressure identified at surface during the release. An alternative method results in a lower release volume.
| Report Received Date | 2024-08-09 00:00:00 |
|---|---|
| Iyear | 2024 |
| Report Number | 20240101 |
| Supplemental Number | 40084 |
| Report Type | Supplemental Final |
| Operator Id | 32603 PHMSA Enforcement |
| Name | Central Valley Gas Storage (Cvgs), Llc |
| Operator Street Address | 919 Milam Street Suite 2425 |
| Operator City Name | Houston |
| Operator State Abbreviation | TX |
| Operator Postal Code | 77002 |
| Time Zone | Pacific |
| Daylight Savings Ind | Yes |
| Location Latitude | 39.380226 Google Maps OpenStreetMap |
| Location Longitude | -122.03241 Google Maps OpenStreetMap |
| Nrc Rpt Num | 1404408 NRC Report How to search |
| Additional Nrc Report Numbers | 1404996 |
| Commodity Released Type | Natural Gas |
| Unintentional Release | 34.72 |
| Intentional Release | 0 |
| Accompanying Liquid | 0 |
| Fatality Ind | No |
| Fatal | 0 |
| Injury Ind | No |
| Injure | 0 |
| Status When Identified | Idle |
| Communication State Fed Ind | Yes |
| Party Initiated Communication | Operator |
| Ignite Ind | No |
| Num Pub Evacuated | 0 |
| On Off Shore | Onshore |
| Onshore State Abbreviation | Ca |
| Onshore Postal Code | 95970 |
| Onshore City Name | Not Within A Municipality |
| Onshore County Name | Colusa |
| Designated Location | Not Applicable |
| Pipe Fac Name | Cvgs Storage Facility |
| Segment Name | Underground Storage Well |
| Federal | No |
| Location Type | Operator-Controlled Property |
| Incident Area Type | Belowground Storage Or Aboveground Storage Vessel, Including Attached Appurtenance |
| Crossing | No |
| Pipe Facility Type | Intrastate |
| System Part Involved | Belowground Storage, Including Associated Equipment And Piping |
| Item Involved | Underground Gas Storage Or Cavern |
| Installation Year | 2024 |
| Manufactured Year | Unknown |
| Material Involved | Carbon Steel |
| Release Type | Leak |
| Leak Type | Other |
| Leak Type Other | Release Of Trapped Pressure |
| Class Location Type | Class 1 Location |
| Could Be Hca | No |
| Pir Radius | 209 |
| Heat Damage Ind | No |
| Non Heat Damage Ind | No |
| Did Occur In Mca Ind | No |
| Est Cost Oper Paid | 0 |
| Est Cost Unintentional Release | 113 |
| Est Cost Intentional Release | 0 |
| Est Cost Prop Damage | 62000 |
| Est Cost Emergency | 45600 |
| Est Cost Other | 0 |
| Gas Cost In Mcf | 3.26 |
| Prpty | 107713 |
| 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 | 824 |
| Gas Flow In Pipe In Mcf | 0 |
| Mop Psig | 1436 |
| Mop Cfr Section | Other View CFR 49 §192 |
| Mop Cfr Section Details | Derived From Calgem Permitted Injection Gradient In Lieu Of Pressure |
| Maop Established Date | 2010-10-29 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 In Storage Field |
| Scada In Place Ind | Yes |
| Scada Operating Ind | Yes |
| Scada Functional Ind | No |
| Scada Detection Ind | Yes |
| Scada Conf Ind | Yes |
| Accident Identifier | Local Operating Personnel, Including Contractors |
| Operator Type | Contractor Working For The Operator |
| 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 | Primary responsibility for the well work had been handed over from the controller/control room to the well work crews |
| Employee Drug Test Ind | No |
| Contractor Drug Test Ind | Yes |
| Num Contractors Tested | 13 |
| Num Contractors Failed | 0 |
| Cause | Incorrect Operation |
| Cause Details | Other Incorrect Operation |
| Operation Type | Other Incorrect Operation |
| Operation Details | The Contractor Well Work Crews Failed To Equalize Pressure Across The Retrievable Packer Prior To Releasing It As Required By The Well Work Procedure. |
| Related Failure Follow Ind | Yes |
| Category Type | Other Maintenance |
| Operator Qualification Ind | No |
| Preparer Name | A** J****** |
| Preparer Title | Director Of Regulatory |
| Preparer Email | A*******@c*************.com |
| Preparer Telephone | 7134947816 |
| Local Contact Name | J*** B****** |
| Local Contact Email | J*******@c***********.com |
| Authorizer Name | A** J****** |
| Authorizer Title | Director Of Regulatory |
| Authorizer Telephone | 7134947816 |
| Authorizer Email | A*******@c*************.com |
| Narrative | Well control was temporarily lost during planned maintenance of the c.V.G.S. 1-l (api10: 0401120925), an ungsf gas storage well. At 11:27 am local time on july 11th, 2024, 1,478 feet of 2-3/8' workstring was ejected from the well. Within thirty seconds, the well was controlled and secured by the onsite crews. There were no injuries. Cvgs began its incident response, including notifying the nrc and other regulatory agencies in accordance with cvgs procedures and applicable regulations. Prior to the loss of well control and in accordance with the well work procedure, the well had a retrievable packer installed at 1,507 feet md and a plug set in the packer at 2,424 feet md intended to function as two downhole isolating barriers between the reservoir and the surface. A few elements of the scada monitoring system were purposefully disconnected to isolate hazardous energy and access the well for the planned work, and the scada system for the rest of the facility was operational and functioning. At some time prior to 11:27 am, potentially overnight, pressure built between the barriers installed at 1,507 feet md and 2,424 feet md. At 11:27 am, the workover crews began to release the retrievable packer installed at 1,507 feet md to retrieve it from the well. As the packer was released, the force from the built-up pressure pushed the workstring and retrievable packer out of the wellbore in approximately 3 to 5 seconds. The gas that built up between the two downhole barriers was released. In less than thirty seconds, the onsite crews secured the well with multiple barriers (master valve and blowout preventer elements). The workstring contacted the electronics of an offset well, which shut down in the intended failsafe condition and provided the initial indications of an incident to the control room via the scada system. The surface piping of three offset wells was contacted and then taken out of service until assessments confirmed the damage was only cosmetic. The well work procedure specified to equalize pressure across the retrievable packer installed at 1,507 feet md prior to releasing it. The purpose of this procedural step is to mitigate the possibility of a failure of the isolating barrier installed at 2,424 feet md. The well work crews skipped this step. The failure of the isolating barrier installed at 2,424 feet md is a contributing factor. The estimated release volume was calculated using the well's inflow performance relationship, the reservoir pressure, and the pressure identified at surface during the release. An alternative method results in a lower release volume. |
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