top of page


The iQ™ is a Segmented Electromagnetic Inspection Tool that Accurately Measures Casing Thickness, Internal Diameter and Material Properties

Probe Technologies Holdings, Inc. (“Probe” or the “Company”), a leading supplier of logging and reservoir monitoring technology to the global oil and gas and geothermal industries, introduces the iQ™, a new multi-purpose inspection tool that provides quantitative measurements of well casing thickness and inner diameter (ID), as well as a comprehensive analysis of casing material properties. It operates in high-pressure wellbores, including those in highly deviated and horizontal wells, up to 20,000 psi, in temperatures as high as 175°C.

Demand for quantifiable well integrity evaluation solution results in the iQ

The iQ was developed in direct response to demand for a quantifiable, reliable and cost-effective intelligent well integrity evaluation solution by independent wireline companies in North America. Highly deviated and horizontal wells require a consistent, easier way to comprehensively evaluate cement and well integrity in a single run. The challenge was to help wireline companies evaluate these wells, which are becoming increasingly complex, particularly in terms of trajectory and tortuosity of the well path. It is critical that potential weak points are accurately identified to avoid well integrity problems, especially in completions that must withstand the extreme pressures required for hydraulic fracturing.

Raising the bar

Unlike other well integrity evaluation tools, the iQ is only one that provides an economic, reliable and simple method of gathering accurate quantitative casing thickness measurements with azimuthal sensitivity, and carrying out comprehensive casing material property analysis.

How is this possible? First, the iQ’s ruggedized mandrel tool design means that it is much more reliable and cost-effective than any other casing thickness tool. Second, it delivers highly accurate quantitative measurements. For example, quantitative electromagnetic (EM) casing ID and properties are assessed through multi-frequency measurements and inversion, and quantitative quadrant casing thickness is assessed and corrected by measured casing properties. Most important, the iQ’s calibration procedures are simple, ensuring that measurements are always accurate, and may be relied upon as a consistent source of data.

“This unique combination means that the iQ is the only tool of its kind to offer such a broad range of well integrity evaluation capabilities in one simple intelligent solution,” said Pouya Mahbod, VP North America Sales for Probe. “When coupled with the fact that it’s affordable and compatible with the Probe Well Integrity Platform, we’re confident that it will soon be the industry’s tool of choice for detailed corrosion evaluation and analysis.”

During the past 18 months, the iQ was put through a series of rigorous tests at Probe’s Technology Center in Fort Worth, Texas. The iQ is currently being qualified for use by a major wireline service company, as well as several other independents in North America.

How it works

The primary advantage of the Probe iQ is that it provides precise casing measurements such as ID, thickness, and material properties, including magnetic permeability and electrical conductivity with quadrant circumferential sensitivity. The patented four-segment receiver incorporated within the tool mandrel measures casing thickness in 90° sections (quadrants) based on remote-field eddy current (RFEC) principles. The measured electromagnetic (EM) field attenuations and phase shifts from transmitter to receivers are quantitatively translated to single-layer casing thicknesses following corrections made based on EM property variations. In addition, the axial differential measurements, which are also measured in quadrants, deliver enhanced axial resolutions of small defects on the casing wall. Meanwhile, the precise casing ID, magnetic permeability and electrical conductivity are derived from multi-frequency measurement and inversion while the EM caliper sensor arrangement satisfies the near-field eddy current (NFEC) conditions. As a result, both internal - and external - casing wall defects can be identified by combining casing ID with quadrant thicknesses when interpreting the data.

When used in conjunction with Probe’s MAC tools, the EM caliper can further determine the non-metallic deposition on the casing. The intelligent measurements algorithm significantly simplifies the calibration procedures, consistently delivering reliable results. To provide a relative tool orientation and monitor shock and vibration, iQ features a tri-axial accelerometer. In addition, an auxiliary temperature sensor in the electronics sub enables complementary monitoring of the tool’s overall operating condition.

Expanding range of Well Integrity Solutions

The iQ is the latest addition to Probe’s range of well integrity solutions, including the MAC™

Multi-Arm Caliper tools, RADii™ Segmented Bond Logging tools, and others. Available in 2-3/4-in. and 3-1/2-in. tool sizes, the iQ measures casing thickness and internal diameter, and casing material properties to identify defects in a wide range of casing sizes.

About Probe

Established in 1994, Probe is widely acknowledged as a leading specialist cased hole logging and reservoir monitoring technology supplier to oilfield services companies around the world. Headquartered in Houston, Probe operates through its extensive network of global representatives and technology and support centers in North America, Latin America, Europe, the Middle East, North Africa and Asia. For more information on Probe and its product portfolio, visit

Recent Posts
Follow Us
  • Twitter Basic Square
  • Facebook Basic Square
  • LinkedIn Social Icon
bottom of page