It's lightning season - Are your downhole gauges and surface electronics protected?
It’s spring again, and that means that we are heading into storm season! Especially in places like Texas and the Mid-West thunderstorms can wreak havoc on infrastructure including oilfield equipment.
If you operate in a region where seasonal lightning strikes are common you’ll know how critical it is that your sensitive electrical equipment features lightning protection!
Figure 1: Lightning GIF courtesy of https://gifer.com/en/gifs/acid-rain
Interesting Lightning Facts
Lightning is the release of large amounts of static electricity that are stored in wet clouds.
Winds inside the cloud are very turbulent and water droplets in the bottom part of the cloud are caught in the updrafts and lifted up to the colder atmosphere which freezes them. The turbulence also has downdrafts in the cloud and push ice and hail down from the top. When the ice meets the water, electrons are stripped off which creates stored energy.
Lighting strikes happen when a strong negative charge in the wet clouds attracts positive charges in the ground. The lighting looks for the path of least resistance which is usually tall building structures, telephone polls, or trees.
Some additional interesting facts about lightning include:
- The majority of electrical storms occur in April, May, June, and July
- Texas averages 3,000,000 to 4,000,000 million lightning strikes per year with approximately 10,000 lightning insurance claims per year
- The surface temperature of air near lightning can reach 50,000°F which is 5 x hotter than the surface of the sun
- Each lightning strike carries 5,000 to 15,000 amps of energy at 40,000 to 120,000 volts. If harnessed safely, the average strike could power 56 homes for an entire day
- In 1769 a warehouse containing 200,000 pounds of gunpowder located in Brescia Italy was struck by lightning resulting in an explosion that killed 3,000 people and demolished 1/6 of the town
It’s no secret that lightning wreaks havoc on upstream oil and gas facilities which are typically in remote areas with an abundance of metal structures such as tanks, wellheads, and pipelines which attract the hits.
Downhole monitoring equipment and communication systems are extremely vulnerable to damage, and if not properly protected can result in expensive workovers in the event of a system failure due to a lightning strike.
Lightning Related Damage To Oilfield Equipment
Damage to oilfield electronics as a result of lightning strikes usually occurs one of two ways:
Direct hits are the worst case and fairly rare (thankfully). Unfortunately, there is not much that can be done to protect surface electronics and downhole gauges when this happens. The energy released from a lightning strike is so powerful that not much could survive a direct hit.
Nearby hits however account for the majority of damage from lightning. Power can move through pipes, powerlines, and the earth for several miles. The damage from a nearby hit is much less severe but the change in ground voltage is enough to short circuit radios, surface electronics, and downhole instrumentation. Most damage is occurred by nearby hits and isn’t always obvious that it happened.
Nearby hits damage equipment through either Galvanically Coupled Surge Voltage, Induced Surge Voltages, or Earth Potential Differences.
An example of Galvanically Coupled Surge Voltage would be if lightning hit a power pole and traveled into your structure.
An example of Induced Surge Voltage is if lightning hit a tree or building and creates a large electromagnetic wave that causes damage to the nearby equipment.
Earth Potential Differences occur when lightning hits a pole or tree and creates a high voltage potential during the duration of the strike and is attracted to structures in the ground such as pipelines and wellheads. This problem is magnified if the electronic equipment has a different earth ground than what it is connected to. Equalization then occurs and equipment can be damaged. An example would be copper cables from wellhead to the SCADA collection point.
What Can Be Done To Provide Lightning Protection?
Fortunately, there are measures you can put in place to provide different levels of lightning protection to your downhole monitoring and surface electronics equipment that can provide protection in the event of a nearby hit:
- Make sure to have an earth ground plan at your facility
- Make sure that instrumentation is properly grounded. Often oil and gas instruments are hundreds of feet away from the central data collection point. Too often two wire RS485 cable is used without a common ground between both sides. This can accelerate damage from nearby strikes as earth ground voltage spikes have nowhere to go
- Make sure that your equipment is surge protected
In addition to these basic measures, you can also ensure that you use quality equipment that is designed to protect itself from surge events such as lightning strikes.
Lightning Protected Downhole Instrumentation Equiptment
Here at GEO PSI our Downhole Gauge systems are built to the IEC61326-1 standard which provides the following important benefits:
- Increased reliability against electrical fast transients/burst surge events such as lightning strikes
- Tested to 4kV, Immunity testing, and electrostatic discharge protection to 15,000 Volts
- RF Radiated Immunity
- Magnetic field immunity
- Protection against voltage dips & interruptions protection on the supply line
- Conducted RF immunity including lightning strikes
- Protection against system failure due to incorrect field wiring, poor quality source power, and improper grounding
Lightning strikes and other sources of electrical surges and interference are a reality that nearly all operators have to deal with. Depending on where you operate the effects of seasonal storms can be devastating resulting in regular downtime and costly repairs.
Ensuring you have the right measures in place and are using the right equipment can ensure site safety and protect valuable sensitive equipment.
Here at GEO PSI we have over a decade of experience developing the best downhole monitoring solutions in the industry, and details like IEC61326-1 levels of protection are what set us apart. We pride ourselves on ensuring that our clients have the most reliable and dependable downhole monitoring solutions possible.
If you would like to know more about our downhole monitoring systems or would like to learn more about how the lightning protection integrated into our systems could benefit you we encourage you to contact us.