What aerial magnetometry can detect in oilfield operations

In oilfield operations, many of the most important risks are not visible at the surface.

A buried line. An abandoned casing string. An old wellhead. A metallic segment that was taken out of service. Remnants of infrastructure that were never documented correctly. Metallic anomalies that appear exactly where teams want to excavate, intervene, or mobilize equipment.

In mature fields, this reality is common. Assets change over time, interventions accumulate, drawings become outdated, and operational memory is not always preserved completely.

Aerial magnetometry helps reduce that uncertainty.

It does not replace technical judgment, and it does not eliminate the need for field validation. But it does make it possible to build a layer of information that can be extremely useful before excavation, maintenance, construction, inspection, or operational intervention.

What aerial magnetometry is

Magnetometry measures variations in the magnetic field.

When buried ferromagnetic materials are present, such as steel, pipe, casing, wellheads, metallic parts, or abandoned infrastructure, they can generate detectable magnetic anomalies.

By mounting a magnetometer on an aerial platform such as a drone, teams can cover field areas efficiently and generate anomaly maps that help identify zones of interest.

The objective is not simply to fly a drone.

The objective is to capture geophysical data from the site and turn it into useful information for making better decisions before work begins in the field.

What it can help detect

Aerial magnetometry can help detect or infer the presence of buried or partially hidden ferromagnetic elements.

In oilfield operations, this can include the following.

1. Buried lines and pipelines

In mature fields, there is not always perfect traceability for every line that was installed, modified, abandoned, or taken out of service.

Magnetometry can help identify alignments or anomalies that are compatible with buried metallic infrastructure.

This can be especially useful before:

• excavation
• line crossings
• maintenance work
• construction of new facilities
• heavy equipment mobilization
• interventions along right-of-way corridors

The value is not only in finding a line. The value is in having a better idea of where infrastructure may exist before work starts.

2. Casing remnants

Abandoned or remnant casing can create operational risk when it has not been identified.

In some areas, especially where there has been historical drilling activity, buried metallic elements may remain even when they do not appear clearly in the available documentation.

Magnetometry can help detect anomalies associated with these metallic remnants, allowing teams to prioritize zones for review or validation before intervention.

3. Abandoned wellheads or legacy well infrastructure

In oilfields with decades of operating history, there may be legacy wells, removed wellheads, abandoned locations, or partially documented well infrastructure.

Even when those elements cannot be identified visually from the surface, their presence can generate meaningful magnetic responses.

Detecting zones compatible with this type of infrastructure can help reduce risk before activities such as:

• well pad preparation
• location construction
• earthmoving
• area rehabilitation
• work near existing or historical wells

4. Undocumented metallic elements

Not every anomaly corresponds to a pipeline or a critical asset.

There may also be metallic components, construction debris, scrap, pipe sections, buried parts, or secondary infrastructure left in the field.

Even when some of these elements are not critical by themselves, they can still affect excavation, civil work, inspection, safety, or planning.

Magnetometry helps separate areas with low signal from areas where the team should pay closer attention.

5. Anomaly zones

One of the most useful deliverables is not necessarily saying, "there is exactly one pipe here."

In many cases, the value lies in generating an anomaly zone map.

That map makes it possible to classify areas that require greater review, care, or validation.

For example:

• zones with a high concentration of anomalies
• possible metallic alignments
• isolated points of interest
• areas where direct excavation should be avoided without additional validation
• potential corridors of buried infrastructure

This helps move from general uncertainty to a clearer prioritization of the site.

What aerial magnetometry should not promise

It is important to be clear.

Aerial magnetometry should not be sold as a magical technology that identifies everything with absolute certainty.

It does not detect plastic, concrete, fiber optics, PVC, or other non-ferromagnetic materials in the same way it detects steel or other ferromagnetic metals.

And a magnetic anomaly should not be confused with a final identification without technical interpretation and validation.

An anomaly may indicate the possible presence of ferromagnetic material, but its interpretation depends on context, survey quality, flight height, line spacing, environmental noise, data processing, and technical review.

The right promise is not "we see everything that is buried."

The right promise is this:

We help identify signals and zones of interest that reduce uncertainty before teams act in the field.

Why it is useful before excavation or intervention

Before excavation, maintenance, construction, or equipment mobilization, the question is not always: what do we know about the site?

The question should be: what do we still not know about the site that could affect execution?

In real operations, that difference matters.

If a company needs to intervene on a line, prepare a location, rehabilitate an area, move machinery, or execute work in a mature field, better understanding possible buried constraints can help it:

• reduce surprises during execution
• avoid damage to existing infrastructure
• improve work planning
• prioritize review zones
• support safety decisions
• coordinate better across operations, engineering, maintenance, and contractors
• document the site more clearly before intervention

Aerial magnetometry adds another information layer before machinery, tools, or personnel enter the site.

Why do it with drones

Magnetometry does not depend exclusively on drones. It can also be performed with ground equipment or crewed aircraft, depending on the case.

But a drone can be a very useful platform in certain industrial and oilfield contexts.

It allows efficient area coverage, controlled flight paths, consistent data capture, and reduced unnecessary personnel exposure in the field.

And when it is combined with capabilities such as LiDAR, photogrammetry, thermal imagery, or gas detection, the survey can become a more complete view of the site.

The value does not lie in the drone by itself.

The value lies in using the drone as a platform for acquiring technical data that can then be transformed into field intelligence.

How data becomes a useful deliverable

Raw magnetometry data should not be the final product for the client.

The client needs to understand what that data means for the operation.

That is why a good aerial magnetometry service should translate into clear deliverables, such as:

• anomaly maps
• prioritized zones of interest
• coordinates for relevant points
• integration with orthomosaics or base maps
• GIS layers when applicable
• technical reports
• recommendations for field validation
• comparison with existing site information
• visual documentation of the surveyed area

The difference between data and intelligence lies in interpretation and presentation.

A technical file that nobody uses does not reduce uncertainty.

A clear, contextual, actionable map can help teams make better decisions.

Cases where it can make sense

Aerial magnetometry can be especially useful in situations such as:

• mature oilfields with historical infrastructure
• areas where drawings are incomplete or outdated
• preparation of new locations or pads
• work near existing or abandoned wells
• excavations in areas with possible buried infrastructure
• pipeline intervention or maintenance
• rehabilitation of industrial areas
• pre-mobilization review for heavy equipment
• validation of corridors or rights-of-way
• support for integrity, maintenance, EPC, or construction teams

Not every project requires magnetometry.

But when there is uncertainty about buried ferromagnetic infrastructure, it can be a high-value information layer.

Magnetometry as part of field intelligence

At StrataIntel, we see aerial magnetometry as one of the core capabilities for reducing uncertainty in the field.

But we do not treat it in isolation.

Magnetometry answers a specific question: where may ferromagnetic anomalies or buried metallic infrastructure exist?

LiDAR answers different questions about terrain, elevation, surface, and geometry. Photogrammetry adds visual context and measurable maps. Gas and methane detection can identify possible emissions or areas of interest. Thermal imagery adds another observation layer for selected assets or conditions.

When these capabilities are combined correctly, the result is not simply a drone survey.

The result is a field intelligence layer that supports operational decisions.

Conclusion

Aerial magnetometry can help detect signals associated with buried ferromagnetic infrastructure such as lines, pipelines, casing, abandoned wellheads, metallic remnants, and anomaly zones.

Its value is not in promising absolute certainty.

Its value is in reducing uncertainty before action begins.

In mature oilfields, where historical infrastructure, accumulated changes, and incomplete documentation can affect execution, this capability can be an important tool for operations, maintenance, integrity, EPC teams, and contractors.

At StrataIntel, we believe better field decisions require better field data.

And aerial magnetometry is one of the most direct ways to begin closing the gap between what is visible at the surface and what may actually exist below it.