Oil and gas assets are really valuable, and you need to track them to ensure they are properly deployed and maintained. RFID can be a huge help in streamlining the tracking of these assets. However, you have to select the right tags to perform in the tough environment of an oil field. In this post, we’ll review the four key attributes of an oil & gas RFID tag.
RFID tags for oil & gas applications have a tough job. They need to endure challenging conditions and handling while still delivering consistent reads.
These tags operate in conditions that are hostile to most RFID tags. This includes:
- Continuous exposure to moisture and fluctuating temperatures
- Nearby large metal objects that interfere with radio frequencies
- Rough handling of tagged assets that exposes the tag to high impact forces
- Chemical washdowns and pressure washes
So, if these tough conditions will damage, dislodge or impair most RFID tags – how can you tag an asset to reliably collect data?
How Can I Tag My Assets Effectively?
It’s possible to find a tag strong enough to survive these conditions, but it must be either a specialized off-the-shelf tag or a custom tag. Either way, there’s a few characteristics you’ll need to consider: durability, effective mounting, proper tuning and RF performance that fits the specific business process about which you wish to gather data.
Obviously, the tag has to be very rugged. The tag will need to be designed to endure the tough conditions it will face in the field.
You can expect your tags to regularly experience high force impact. To prepare for this, tag manufacturers will strengthen the construction of the tag by overmolding it with plastic or encasing it with steel. Adding tough materials that protect the antenna and the chip makes the tag more tolerant of rough handling and impacts.
The tags have to survive the stresses imposed by wide variation in temperatures over extended deployments in the field. To do so, the tag must be built with the right materials that will not fracture or degrade with repeated temperature cycles.
When moisture penetrates a tag, it can exacerbate the negative effects of temperature. It also accelerates the oxidation and decay of the electrical components of the tag.
The tags must not deteriorate when exposed to the chemistries likely to occur be present in the oil field and in oil processing.
Many plastics degrade with extended exposure to sunlight. The materials from which tags are made must resist this degradation.
Overall, the tags need to be intrinsically rugged and tolerant. And, because assets last a long time, they also have to endure these conditions for extended periods.
Like the tag’s construction, the mounting method of the oil field tag can enhance or detract from the tag’s survivability.
Many ‘off the shelf’ RFID tags are mounted with a pressure sensitive adhesive. This superficial mounting scheme does not work well in the oil field. Rugged handling and extreme conditions can knock the tag from the surface.
There are a couple of more effective options.
Mount the Tag in a Protective Location
The least troubling scenario is to mount the tag somewhere it’s protected, like near a right angle. Some assets have locations that naturally protect tags, like a corner or the space under a flange. However, this is the exception. It can be challenging to find this type of mounting location.
Embed the Tag
Another way to mount an RFID tag is to embed it in the oil field asset. With this method, you’d drill a hole or mill a trench, drop in the tag and backfill with epoxy. This is great for durability and retention because it protects the tag from adverse agents and impacts.
The drawback is that this method is invasive. Drilling a hole could compromise the structural and functional integrity of the asset. To embed a tag, you have to do the engineering analysis to make sure this isn’t a problem. Often it isn’t possible to alter the asset to add the tag.
Use Durable Mounting
The last way to mount an RFID tag on an oil field asset is to attach it in way that’s as durable as the asset is. The most common method of attaching a tag is to use a durable band or wire that wraps around the outside of the asset. This way, the tag will stay on even if you subject it to substantial abuse. The only way to remove the tag is a deliberate act of cutting the band. This is the most common method because it’s both noninvasive and effective.
UHF RFID frequency standards vary from one region of the globe to another. Sometimes oilfield companies ship their tagged assets from continent to continent. And when tags cross borders, they enter different RFID regimes with different frequency standards.
An RFID tag tuned to respond well to a reader in the US, which transmits a query signal in the 902-928 MHz range, may respond very poorly to a signal transmitted by an EU reader, in the 865-868 MHz frequency range.
Tags need to be engineered to provide a good response over the full range of frequencies in the geographies in which it might be located.
If you don’t know where the asset’s going to be used, you need to use a tag that will respond to worldwide RFID standards. A worldwide tag will respond to an incoming query wherever the asset finds itself. That’s a different tag, tuned differently.
Engineered to Improve a Business Process
User and application requirements dictate the functionality of the tag. For a tag to perform for oil & gas, the tag manufacturer must engineer the tag to work in the particular business processes where data collection is occurring. Tags serve two major purposes in the oil field.
Many oil field assets need periodic inspection, maintenance, refinishing or safety recertification. Records of these processes for each item must be carefully maintained.
Common practice is to etch or stamp serial numbers into the assets. The problem is, these numbers can be effaced by abuse, obscured by dirt and muck or abraded off. RFID tags provide an easily read alternative to these numbers. With RFID, you don’t have to do manual identification, like reading a serial number covered in dirt.
In this process, the individual working with the asset is close by, inspecting the part or performing an operation on the part. A few feet of read range will enable the operator to identify the asset. The shorter read range tags needed for this business process tend to be small and less costly than longer read range tags.
On the other hand, some owners are more concerned about the location of assets. For this process, you could use RFID to answer questions such as:
- Has the asset left the factory?
- Where is it in the yard?
- What rental assets have we sent to customers?
- Where is the asset installed in the pipeline?
To use a tag for providing location information, you’d need a much longer read range so you can locate the tag at a distance.
Say for example, you wanted to automatically ID a pipe as it goes through an entrance gate on the back of a truck. You’d have to have a tag with a long enough read range to be reliably read as the truck pulls through the reader port at the gate.
Because of their longer read ranges, these tags will also need to be larger and more expensive. You wouldn’t want to use this larger and more expensive tag unless you’re accomplishing this specific task.
RFID tags offer numerous benefits for tracking oil field assets. But to reap those benefits, you’ll need a tag that can perform under tough conditions while meeting the requirements of your application.