Incident Field Report
File Number: INC_2015_138
CVA Number: 1516-226
Pipeline/Facility Name: Spectra Pine River Gas Plant
Location: Chetwynd British Columbia
Date of Incident: 26/11/2015 11:22 MT
Date(s) of Field Visit: Nov 30- Dec 05, 2015
Three NEB Inspection Staff: Inspection officer, Staff engineer, Professional leader safety
Located approximately 20 km up a radio-controlled road on Commotion Mountain near Chetwynd BC, the Pine River Gas Plant was built in 1979 (Trains A & B) with a major expansion in 1993 (Train 3). This is a sour gas complex with normal H2S concentration in raw gas being in the range of 10–20 vol %. The solvent used for the gas sweetening process is Sulfinol (Sulfolane + DIPA + Water). Sulphur is extracted from the acid gas using three Sulphur Plant Trains (A, B and 3) in the molten form. This molten sulphur is then piped to Enersul owned plant at the base of the mountain for prilling and shipping.
The sweetened gas, after dehydration, is transmitted down the pipeline for customers.
The combined rated capacity of three process trains is 560 mmscf/d while that of the three Sulphur trains is 2000 t/d.
Description of Incident
-An unknown volume of vapour was released from the Process Train # 3 Amine (Sulfinol) Surge Tank in the form of a visible cloud during a start-up operation.
-Plant staff were mustered, no injuries were reported and all personnel were accounted for.
-Upon ceasing the start-up activity (circulation of amine solution), the release stopped and the cloud dissipated
-The plant was isolated and operations suspended
-Non-essential staff were sent home
-Spectra assessed the situation and the plant will not be restarted until approval is granted from the General Manager of Operations
-No other obvious effects to people or the environment has been noted
-Nearest public residing in the area are approximately 20km away in a location called Hasler Flats. They were notified by Spectra.
-Emergency Management BC was also contacted
-No first responders were engaged
Summary of On-Site Activities
Nov 30, 2015
-NEB inspection staff safely arrived at Chetwynd British Columbia at 15:40
-contacted Spectra personnel, the Director Pine River Gas Plant (PRGP) at 16:30 discussion as follows:
>>plant start-up is progressing at a measured and safe pace
>>the earliest that non-essentials will be permitted onsite at the PRGP is estimated to be midday on Wednesday.
>>NEB Staff met with Spectra personnel at the Spectra pipe shop morning of Dec 1, 2015, to discuss progress and explore whatever can be assessed remotely from the plant (e.g. Plant DCS trends)
Dec 1, 2015
-Area Director of the PRGP met NEB staff at 8am and we followed him to the Spectra Pipeline shop office in Chetwynd.
-Health and Safety Specialist conducted a plant orientation and a detailed review of revised Muster Procedure (PRGP SWP 12A Muster Procedure Revision #13 November 29, 2015) in anticipation of a plant visit later this week by NEB personnel
-held a discussion with General Manager of Transmission and NGL and Area Director regarding:
>>plant start-up status (unable to visit plant until at least Wednesday)
>>pigging practices and arrangement at the plant inlet>>status of Spectra's incident investigation
>>DCS trends prior to and during the incident, including H2S and CO2 concentrations
-NEB staff then followed Area Director and General Manager of Transmission and NGL out to the field to see the following:
>>three community emergency sirens located in the valley below the plant (Hasler Flats) (these sirens are triggered from the PRGP control room and are tested every 4th Thursday of the month at 4pm. This was the same day as Inc_2015-138. Photo of signage was taken as evidence of this statement.
>>B.C. Ministry of the Environment (MoE) ambient air monitoring trailer nearest the plant. Spike on H2S reading of 14 ppb appears to have occurred around the approximate time of the incident. Reportable threshold is 19.8 ppb. MoE originally thought to be a calibration spike, but subsequent evaluation identified the spike was an actually recorded event.
>>Spectra and NEB staff drove to the Enersul facility that receives the liquid sulphur from the plant and viewed Sulphur pipeline.
>>the discussion with the Area Director and General Manager of Transmission and NGL concluded in the field.
-Area Director will be contacted in the morning to determine plant start-up status and the anticipated timing to access the plant.
Dec 2, 2015
-had a morning call with Area Director on the plant status. They are still going through start-up activities. Non-essentials are still prohibited from the site.
-staff remained ready to attend the site all day but were not contacted to do so
-Area Director provided an update in the evening as reflected in the Spectra semi-daily report for Dec 2, 2015.
-Received Pine River Gas Plant Operator Qualifications.
-All eleven Control Room Operators training summaries were received and reviewed as follows:
>>The annual training check was comprehensive and curent (annual)
We requested the Power Engineer certificates of the operators so that NEB staff could also review.
-Requested communications documentation for notification with the community of Hasler Flats (received this December 3, 2015)
Dec 3, 2015
-had a morning call with the Area Director on the plant status. Spectra are still going through start-up activities, the good news being that liquids are no longer appearing at the inlet coalescing filters. Non-essentials are still prohibited from the site.
-Area Director provided an update mid-afternoon as reflected in the Spectra semi-daily report.
-as per our discussion, given the start-up progress now that liquids are no longer present at the inlet and inlet H2S levels are trending to normal values, there is a very high probability the plant will be online and stable tomorrow and that we will get on site on Friday.
Dec 4, 2015
-had a morning call with Area Director on the plant status. Start-up progress was hampered by a lack of raw inlet gas; freezing rain in the field overnight prevented CNRL personnel from being able to safely access the well sites and receipt points. As of Friday morning CNRL was gradually able to get at the field locations.
-regarding the amine system, all process trains have now achieved a full high-pressure circulation through the regen system and surge tanks; presumably the contaminant that created the vapour cloud incident is now fully stripped out of the amine.
-Non-essentials are still prohibited from the site and the plant will not be able to receive us today.
-NEB staff took the opportunity to meet with the RCFA and TapRoot investigations teams at the Spectra pipe office in town. They are making good progress. The TapRoot lead indicated we should see a copy of the report within two weeks or later; we indicated that we expect a preliminary copy of the TapRoot report much sooner than that. (We expressed this expectation with General Manager Gathering later in the day and he committed that we would get a preliminary TapRoot report next week.)
-CNRL is participating in the investigation process.
-following the meeting with the investigation teams we met with the Area Director, to express an expectation that the plant will need to be stabilized
sufficiently to permit us access to the plant on Saturday afternoon and Sunday morning if necessary; even if it means they leave a train down to accommodate us then. The Area Director, escalated the request to the General Manager Gathering and Processing. The General Manager Gathering and Processing accepted our request; we will be deemed "essential" and will proceed on site Saturday afternoon/ Sunday morning if necessary (depending on the amount of time and what we can observe on site.
-NEB staff reviewed addition operator certifications (Power Engineer documentation) and had no issues with the qualifications and documentation that was
Dec 5, 2015
-met Area Director, and Manager of Facilities Engineering, North Montney (who is leading the investigation process) at the office in town, then followed them up to the plant.
-activities at the plant were as follows:
>>sign in with Security
>>obtain a permit for use of a camera in the plan
>>participated in a Field Level Hazard Assessment
>>request that a worker attend the plant tour with us
-proceeded into the plant with appropriate PPE, and individual four head gas monitors with the Area Director PR, Manager Of Facilities Engineering, North
Montney, Operations Team Lead/ Chief Power Engineer) and an operator to see:
>>full flow amine filters
>>train 3 amine surge tank
>>LP flare knockout drum
>>various other equipment
>>muster points, wind socks
-good discussion was held with Spectra employees, as well as with the control room operators on our return. All Spectra personnel were open and frank in discussions.
-a closeout meeting was held with the Area Director, and Manager of Facilities Engineering, North Montney at the plant with the following noted
-NEB staff had no further questions at this time
-NEB staff had no concerns with their approach to the safe re-start of the plant
-NEB staff requested that weekly updates on the RCFA and TapRoot investigations be forwarded to the NEB
-NEB staff requested continued semi-daily re-start updates until further notice
-NEB staff expressed an interest to be invited to the next ad-hoc town hall with the Hasler residents after the RCFA and Tap Root investigations were complete.
-Non- essential personnel have been denied access to site as a safety measure as the PRGP is in an emergency staged start-up status. No concerns.
No environmental issues, MoE is notified if thresholds of 19.8 ppb are exceeded.
NEB Staff are awaiting results of the RCFA and TapRoot investigations, and are getting weekly updates.
-Non-essential personnel have been denied access to site as a safety measure as the PRGP is in an emergency status. Security staff are on site.
NEB Staff Follow-up Requirements and/or Recommendations
NEB Staff are awaiting results of the RCFA and TapRoot investigations.
NEB Operations Technical Specialist