CTES, LP, of Conroe, Texas, has developed a device to provide continuous, cost-effective inspection of coiled tubing. The Argus Coiled Tubing Inspection Device uses an array of 12 ultrasonic (UT) probes arranged around the coiled tubing (CT) to make 12 wall-thickness, six diameter and three ovality measurements, continuously as the CT is run in and out of the well, taking 1,200 measurements per second. No UT coupling fluid is required, making the system practical and easily usable in CT service operations.

Wall thickness of CT is often reduced during its life due to acid and rust corrosion, erosion from sand laden fracturing fluids and abrasion with wellbore tubulars. High-pressure applications can also cause changes in CT due to ballooning. In these cases, the Argus is being used for continuous monitoring of CT to detect wall loss early and avoid catastrophic failure.

Argus uses a patented polyurethane packer element (similar to a stripper packer element) to provide the coupling required between UT probes and the pipe, eliminating the need for clean water required in other UT inspection systems. This allows the device to be small, light weight, and to operate during standard CT field operations, eliminating the need for a separate inspection yard.

According to the company, the Argus is much less expensive than conventional electro-magnetic inspection systems. For example, service costs of one North Sea inspection with existing devices in some cases have been more than the total cost of four complete Argus systems. Also, Argus inspection results are easy to read and do not require a pipe inspection expert to interpret results.

By the end of 2005, 22 Argus devices (19 of which are marketed by Schlumberger as "CT InSpec") will have been built. These devices have been run in the United States, Mexico, Columbia, Russia (Sakhalin Island) and the Middle East.

For more information, visit www.ctes.com.

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