Flaring systems, including flare stacks and flame arrestors, are a common piece of equipment in the oil and gas industry. They are used to burn gases before they enter the atmosphere to ensure no harmful chemicals are released into the environment. This is why the safe operation of the flaring system is essential. Read on to learn more about their importance and methods to monitor the main flare.
Why is Monitoring the Flare Stack Essential?
Flares that do not ignite properly tend to release harmful gases into the atmosphere, often putting the infrastructure and personnel at risk. This also leads to non-compliance with environmental regulations. Thus, it is essential to confirm that the main flare or pilot flare remains lit at all times.
Alberta Energy Regulator (AER) Directive 060
According to the AER Directive 060, Upstream Petroleum Industry Flaring, Incinerating, and Venting, and the Saskatchewan Energy and Resources Ministry Directive S-20, sweet gas, sour gas, acid gas, flares and incinerators should have reliable systems to ensure continuous ignition.
- Sweet gas – refers to natural gas extracted from crude oil and gas wells.
- Sour gas – is natural gas that comprises a significant amount of hydrogen sulphide (H2S). It is flammable and colourless. Due to the presence of H2S, it smells like rotten eggs.
- Acid gas – includes gaseous compounds that form an acidic solution when dissolved in water. A few common types are hydrogen sulphide (H2S) and carbon dioxide (CO2). Other categories include nitrogen oxides (NOx), hydrogen fluoride (HF), hydrogen chloride (HCl), and sulphur oxides (SO2 and SO3).
Once the acid gases come in contact with the water present in the atmosphere, it forms acid rain. It is harmful to animals, humans, and the environment. Continuous monitoring of flared gases and pilot flames can help ensure that the gases are ignited properly and make sure they do not cause much harm when released into the atmosphere. Also, it assures compliance with essential government regulations.
Common Methods to Monitor Pilot or Main Flare
A flaring system typically uses one of the following sources:
- Ionized Gas – Flame ionization detection
- Heat – Thermocouples
- Light – IR or UV systems
- Sound – Acoustic systems
Let us take a detailed look at them individually.
- Flame Ionization
High-tension ignition systems typically use a flame ionization detector to monitor the flame. They use the same cable for ignition as well as monitoring.
- Thermocouple Flame Detection
It is a common system typically used along with high energy ignited pilot burners. This is a reliable unit and has the thermocouple mounted on the pilot burner nozzle.
- Optical Monitoring
It uses a special camera lens to detect the presence of the ultraviolet or infra-red light from the flare. It is useful when it comes to determining the presence of the flame.
- Acoustic Monitoring
It is similar to the optical monitoring detection method. The unit is placed away from the pilot and is designed to respond to the distinct sound signature of a pilot burning.
- Without Pilots
Typically, pilots are used in direct spark ignition systems or pellet-driven ignition with a video link or light-based system. It helps to confirm the presence of hydrocarbon gas to work effectively with ignition units. The latest Ultrasonic Flare Gas Meters are typically used for this purpose.
Reliable Flare Stacks for Oil and Gas Facilities
At Aspire Energy Resources Inc., we have the required expertise and skills when it comes to flare stack design, fabrication, and spacing requirements. We have experts to ensure that the vent stacks and other flaring systems meet the mandatory legal requirements.