A. J. KHAN, Contributing Author, Riyadh, Saudi Arabia
Design engineers put forth their best efforts to forecast all risks for their processing plant and strive to embed optimum controls in design, commissioning, operations and maintenance to prevent these risks during the plant’s lifecycle.
The most difficult risks to predict and control are natural hazards triggering technological disasters (NaTech) that are driven by Mother Nature. This includes everything from earthquakes, floods, storms, tsunamis, landslides, wildfires, soil erosion, etc., that can impact the chemical and oil and gas industries, resulting in the release of hazardous materials.1
Lightning strikes are one of these elusive threats that can catch any well-prepared asset operator off-guard. One such incident occurred on June 3, 2023, and with irrefutable video proof. A security camera captured the moment when lightning struck a naphtha tank at an oil refinery in Louisiana, U.S., resulting in an immediate fire and an evacuation order for people within 1.5 mi. of the facility.2 Fortunately, there were no injuries during the incident and the subsequent emergency response. However, the impact on the environment and potential asset damage cannot be trivialized. While a lightning strike may sound like a black swan event, the evidence paints a starkly different picture. According to the U.S. Bureau of Labor Statistics, lightning strikes an oil refinery about once every 2 yr, a frequency that varies based on each facility’s location.3
Defining the problem. Lightning is an electric phenomenon in which electric charges accumulated in the atmosphere are discharged into neighboring clouds or to the ground.4 While lightening is visually spectacular from a distance, it can cause disastrous damage when it strikes on ground. The most significant property of lightning is its complexity. A “standard lightning strike” does not exist—its characteristics are driven by numerous factors such as terrain, altitude, latitude and time of the year. Study suggests that there are more than 1.5 B lightning strikes globally each year,5 with results varying from damaged trees to millions of dollars of equipment or facility damage.
The BS/EN IEC 62305 standard, “Protection against lightning—General principles,” identifies four major sources of damage (FIG. 1):
Published material suggests that surge voltage damage can occur over a radius of up to 2 km from the location of the lightning strike, making it even more challenging to manage.5
Repercussions of a lightning strike. Oil and gas and petrochemical operations typically involve the processing, handling and storage of flammable materials under high pressures and temperatures. This makes them highly susceptible to lightning risks, which can cause issues with the following:3
Personnel safety. Industrial workers are vulnerable to lightning risks while working outdoors or near tall structures. Many fatalities have occurred in the past due to direct/indirect lightening, thermal burns, cardiac arrests and severe musculoskeletal injuries. Safety protocols have been devised by most operators to prevent personnel from going into the field during lightning storms and keep them inside buildings protected with lightning protection systems (LPSs).
Fires or explosions. Ignition control poses significant challenges, especially for downstream operators handling hydrocarbons with low flash points. The probability of the accumulation of flammable vapors can never be zero, even with the best maintenance programs in place. A lightning strike can ignite them, leading to fires or explosions.
Storage tanks. Storage tanks are used in most facilities to hold significant volumes of flammable/hydrocarbon inventories. A lightning strike on these tanks or nearby structures can cause sparks or electrical discharge, resulting in damage to the tanks and the subsequent release and ignition of hazardous materials.
Process equipment. Process plants involve complex processes with various types of equipment, including distillation columns, heat exchangers, reactors and pipelines. Lightning strikes can induce power surges and electrical discharges that might impact the equipment or their safety critical controls. This can cause production disruptions or potential safety hazards.
Electrostatic hazards. Lightning can create substantial electrostatic charges during its discharge. These charges can accumulate on equipment, storage tanks or other conducting objects within the process plants. If not adequately grounded, these charges can cause static discharges, which can ignite flammable vapors or cause damage to sensitive electronic systems.
Secondary effects. Lightning strikes can result in secondary effects, such as power surges or electrical disturbances in the refinery’s electrical systems. These disturbances can affect control systems, communication networks and other critical infrastructure, leading to operational disruptions, safety risks or equipment failures.
Controls. To protect workers and the environment from lightning risks, industrial design practices have developed several preventive and mitigative safety measures.
Design practices. Various standards are being used by the industry—e.g., American Petroleum Institute (API) RP 2003, “Protection against ignitions arising out of static, lightning and stray currents”; National Fire Protection Association (NFPA) 780, “Standard for the installation of lightning protection systems”; and BS EN/IEC 62305, “Protection against lightning.” These standards provide guidance related to the design of an LPS, as well as how to conduct risk assessments for the prevention of injury to personnel and physical damage to structures and the electrical systems within those structures. The utilization of competent resources and applicable standards and legislations can help prevent the risk of lightning at the facility. The most common components of an LPS are lightning rods: metal rods that are placed on the highest point of a facility. Lightning rods attract lightning strikes and direct the electricity to the ground, where it is safely dispersed.
Maintenance and inspection practices. It is vital to identify LPS components as safety critical devices [health, safety and environment-critical equipment systems (HSE-CESs)] and maintain them effectively throughout their lifecycle. Performance standards for the upkeep of HSE-CESs should include industry best practices, standards and legislations that ensure the frequent monitoring and maintenance of each system and its components. Earthing, bonding, continuity checks, corrosion monitoring, etc., are mandatory pre-requisites for a sound LPS implementation.
Surge protection devices. In the event of a lightning strike to connected power circuits or associated equipment, surge protection devices are designed to protect electrical equipment by implementing redirection for an overvoltage event. This can ensure safety critical controls remain available and prevents costly downtimes.
External support. Numerous competent consultants/companies that can help with the design, inspection, maintenance and audit of an LPS are available in the market. This is a cost-effective solution for companies that cannot afford to hire competent resources for the long term.
Fire suppression systems. Fire suppression systems can quickly extinguish fires that are caused by lightning strikes. They typically consist of water sprinklers, foam dispensers and dry chemical extinguishers. The latest advancements in fire detection have made the mitigation process fast and effective, offering total flooding of protected enclosures in a matter of minutes.
Employee training and evacuation procedures. Employees should be trained to safeguard life and assets during NaTech scenarios. Emergency evacuation procedures should be stringent enough to cover major scenarios and practiced enough so that personnel follow them whenever needed. Such measures ensure employees take the right steps to safeguard life, assets and the environment during an unforeseen event.
Takeaways. With an alarming increase in extreme weather events around the globe,6 organizations should configure their operations to manage these abnormal events in the most effective manner. The COVID-19 pandemic has already proved that black swan-type events are not only probable, but are, in fact, very possible. Industry’s best defense is to refer to relevant expertise and continuously strengthen safeguards against everything highlighted in risk registers. HP
LITERATURE CITED
Aamish J. Khan is an Operational Safety consultant who has been supporting various renowned companies in the oil and gas, petrochemicals and utilities sectors in their safety culture enhancement journey for two decades. His multifaceted experience includes operations leadership, occupational safety, process safety management, and integrity assurance and audit, enabling him to identify, analyze and treat risk effectively throughout the asset’s lifecycle. He is now involved in co-authoring the CCPS Safe Work Practices guidelines, with the objective of enhancing the sharing of lessons learned across global industry and softening the safety impact on workers’ lives. Khan is a graduate chemical engineer and earned an MS degree in enterprise risk management from Boston University, Massachusetts, U.S.