The US Chemical Safety Board (CSB) has released a new safety video to improve practices in the oil and gas sector following the Aghorn Operating waterflood station incident in 2019, which claimed the lives of an employee and his spouse.
The safety video explores the events leading up to the fatal hydrogen sulphide release at the Odessa, Texas facility on the evening of 26 October 2019 and is designed to improve understanding of the incident’s underlying causes and to raise standards.
The CSB wants to make sure that companies operating oil and gas facilities learn the lessons highlighted in the final report and implement appropriate safeguards and training.
The hydrogen sulphide release fatally injured an Aghorn employee who was working as a pumper at the facility. It also fatally injured his wife who drove to the site to locate him after he did not return home.
The video includes a new animation of the events that led to the fatal toxic gas release.
It also features interviews with the CSB’s chairperson and CEO Dr Katherine Lemos and Lauren Grim, the supervisory investigator, who reviews the event and the six serious safety issues identified in the investigation. Grim also discusses the safety improvement recommendations made to Aghorn Operating, Inc.
As the CSB investigation notes, the Aghorn Operating waterflood station is used as part of a process to extract oil from underground reservoirs in West Texas.
During extraction, oil comes out of the ground with some water with it, which is subsequently removed. However, the water can contain some residual oil and other contaminants such as hydrogen sulphide, a toxic gas.
At the Aghorn waterflood station, the company uses pumps to pressurise and inject water back into the oilfield, which adds pressure to the reservoir and allows a large quantity of oil to be extracted.
The CSB’s report, published on 21 May, notes that on the night of the incident, the waterflood station’s control system activated an oil level alarm on a pump.
Jacob Dean, an Aghorn pumper, was notified, drove to the waterflood station, and attempted to isolate the pump from the process by closing two valves. The CSB investigation, however, found that the pumper failed to isolate the pump from energy sources before performing the work.
While the employee was in the pump’s vicinity, it automatically turned on, and water containing the toxic gas escaped into the pump house, overcoming and fatally injuring Dean.
'The report determined that additional safeguards are needed to help ensure that a similar event is prevented'
In its investigation, the CSB found that a plunger on the pump had shattered, which had allowed the release to happen. Due to the limitations of the available evidence, however, the US safety body was not able to determine whether the pump failure and toxic release happened before the pumper arrived at the facility or when the pump automatically turned on while the employee was closing the valves.
After a couple of hours and concerned that he had not returned home, Dean’s spouse Natalee drove to the facility with their two children to check on him. She located her husband on the pump house floor and was also overcome and fatally injured by the toxic gas. The children, who had remained in the car, were not injured.
The report identified six safety issues at the Aghorn facility:
- The pumper was not wearing his personal hydrogen sulphide detection device inside the pump house when the incident happened, and there was no evidence that Aghorn management required the use of the devices.
- Aghorn did not have any written lockout/tagout policies or procedures at the time of the incident. The pumper did not perform lockout/tagout to de-energise the pump before performing work on it.
- Although the pump house could be ventilated by two bay doors, exhaust fans and natural vents, the CSB could not confirm whether the fans were operational at the time. The two bay doors were about 60% open and the building was not adequately ventilated during the incident.
- Aghorn Operating, Inc’s formal company safety or operational policies and procedures were incomplete and inadequate.
- Although the waterflood station was equipped with a hydrogen sulphide detection and alarm system, its control panel did not receive signals from the internal and external detection sensors on the night of the incident, and, therefore, did not trigger either of the two alarms.
- Aghorn had deficient site security – when an employee is working at the facility, the company’s informal policy allows the access gates to be left unlocked. This meant the pumper’s spouse could drive directly to the waterflood station and enter the pump house where she was fatally injured.
The CSB made a number of recommendations to Aghorn Operating, Inc to improve safety at all waterflood stations where the potential exposure to dangerous levels of toxic hydrogen sulphide gas exists. These include:
- Mandate the use of personal hydrogen sulphide detection devices;
- Develop a site-specific, formalised and comprehensive lockout/tagout programme for each facility;
- Commission an independent and comprehensive analysis of each facility to examine ventilation and mitigation systems;
- Develop and demonstrate the use of a safety management programme that includes a focus on protecting workers and non-employees from hydrogen sulphide;
- Ensure that hydrogen sulphide detection and alarm systems are properly maintained and configured, and develop site-specific detection and alarm programmes and associated procedures;
- Ensure that the hydrogen sulphide detection and alarm system designs employ multiple layers of alerts unique to hydrogen sulphide; and
- Develop and implement a formal, written, site-specific security programme to prevent unknown and unplanned entrance of those not employed by Aghorn.
In addition, the US safety body made two recommendations to federal and state regulators, the Occupational Safety and Health Administration (OSHA) and the Railroad Commission of Texas.
The CSB recommended to OSHA that it issue a safety information product that meets the requirements for protecting workers from hazardous air contaminants and from hazardous energy.
It also recommended to the Railroad Commission of Texas to develop and send a Notice to Operators to all oil and gas operators that fall under its jurisdiction that describes the safety issues outlined in the CSB report.
Lemos said: ‘Waterflood stations are common throughout Texas. The CSB report determined that additional safeguards are needed to help ensure that a similar event is prevented.’