OCTG Temperature Measurement

Temperature Control for Oilfield Tubular Goods

Seamless steel tubes are used for down-hole drilling of oil and natural gas and also for above-ground transportation of oil and natural gas. Williamson pyrometers are used to monitor the forming and heat treating of the ends of the so-called down-hole tubes as a part of the threading process. Williamson pyrometers are used to monitor the temperature of the transportation and distribution tubes as a part of the coating process. The FBE coating process, in particular, requires a tight control of temperature.

Williamson Wavelength Technologies

Surface scale, surface contamination, emissivity variation, sensor alignment, temperature gradients and changes in surface texture are all significant issues for OCTG temperature measurement. Williamson sensors are uniquely able to compensate for these problematic application issues because Williamson sensors are as much as 20 times less sensitive to temperature gradients, surface contamination, and scale.

Tube End Heating

Application Overview

Tube ends are often heated then upset (formed) to increase or decrease the diameter or wall thickness to allow pipes to be joined end-to-end. In addition, after drilling, threading, welding or mechanical deformation, a heat treatment is performed in order to harden the metal or to eliminate residual stresses.

Williamson Wavelength Advantage

Surface scale, surface contamination, emissivity variation, sensor alignment, temperature gradients and changes in surface texture are all significant issues for this application. Williamson sensors are uniquely able to compensate for these problematic application issues because Williamson sensors are as much as 20 times less sensitive to temperature gradients, surface contamination and scale.

Williamson dual-wavelength sensors are recommended for most tube end heating applications; however, short-wavelength single-wavelength sensors are recommended when viewing through flames. Because ID and OD temperatures can vary, it is best to measure both.

Pyrometer Benefits
  • Consistent product deformation.
  • Consistent product mechanical properties
  • Documented Thermal History of each Pipe
  • Available in a fiber-optic configuration for easy installation
Wavelength Technology
  • Dual-wavelength sensors are as much as 20 times less sensitive to surface scale, gradients and surface contamination compared to competitive two-color sensors and automatically compensate for emissivity variation, changes in alloy and surface.
  • Narrow-band single-wavelength sensors are 4 to 20 times less sensitive to surface scale, temperature gradients, surface contamination, emissivity variation and alloy changes compared to competitive long-wavelength sensors.

Welded Seam

Application Overview

Tubes used for oil country applications may require accessories like (drill bits, for example) to be welded onto them. The welding process and the subsequent annealing process are monitored and controlled using infrared thermometers.

Williamson Wavelength Advantage

In addition to the usual application issues – emissivity variation, surface contamination, and surface scale, sensor alignment is by far the most critical application issue for this application. Traditional infrared thermometers require precise alignment to the very thin welded seam. However, Williamson recommends a different approach. Because Williamson dual-wavelength sensors uniquely tend to measure the hottest temperature viewed, when supplied with a large optical viewing area, the Williamson sensors are essentially self-aligning to the critical welded seam. The Williamson sensors provide this significant technical advantage because of a greater separation between measured wavelengths.

Pyrometer Benefits
  • Consistent weld quality.
  • Consistent product mechanical properties
  • Documented thermal history of each pipe
Wavelength Technology
  • Dual-wavelength is 20 times less sensitive to surface scale, gradients and surface contamination compared to competitive two-color sensors
  • Dual-wavelength automatically compensates for emissivity variation, changes in alloy and surface.
  • Dual-wavelength self-aligns to the hottest temperature viewed.

Induction Heat Treat

Application Overview

Once cast or pierced, seamless pipes and tubes must be annealed to relieve residual stresses resultant from the forming process. In an induction heating process, the pipe is passed through a series of induction heaters to achieve the desired time-temperature profile.

Williamson Wavelength Advantage

When an induction furnace is used, most traditional infrared pyrometers struggle with the surface scale that typically forms. Williamson dual-wavelength sensors are as much as 20 times less sensitive to scale compared to competitive two-color sensors because of the greater separation between wavelengths

In most cases the infrared pyrometer is mounted to view the pipe as it exits the induction coil. The traditional sensor configuration may be used when there is plenty of space to mount it safely out of harm’s way. However, for applications where space is a premium or optical access to the heated pipe is challenging, a fiber-optic configuration is preferred. When access to the heated pipe is an issue, Williamson offers a range of non-conductive rigid light pipes that can be inserted into tight spaces, including through the windings of the induction coil.

Pyrometer Benefits
  • Consistent and Uniform Product Properties
  • Shorter Heating Cycles
  • Reduced Fuel Costs
Wavelength Technology
  • Williamson Dual-Wavelength sensors compensate for emissivity variation and are as much as 20 times less sensitive to scale compared to two-color technology.
  • Williamson Dual-Wavelength sensors are as much as 100 times less sensitive to misalignment and optical obstruction compared to two-color technology.

Tube Coating

Application Overview

Coatings and passivation treatments are commonly applied to pipes and tubes to prevent or retard corrosion. Acrylic, epoxy compounds, and polyester-based paint, represent the most common coatings for oil country tubular goods. Pipe or Tube temperature directly affects the quality and speed of the coating process. Consistent tube temperature is therefore critical.

Williamson Wavelength Advantage

The emissivity of pipe and tube varies dramatically from alloy to alloy and from supplier to supplier. In addition, changes in surface texture and surface contamination will influence the emissivity value.

Pyrometer Benefits
  • Consistent coating surface finish
  • Consistent Adhesion
  • Optimized line speed.
Wavelength Technology

Williamson offers a family of products designed to address these challenging measurement issues. A different sensor model is recommended for each type of coating measurement.

Consult With One of Williamson’s Temperature Experts

We would love to discuss your temperature measurement application with you.

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