Increase reservoir understanding with high-precision measurements 

The SpecStar®  spectral gamma ray service provides natural gamma ray spectroscopy, elemental concentrations of potassium (K), uranium (U) and thorium (Th), and bulk azimuthal gamma ray measurements. These elemental concentrations form the basis for a variety of formation evaluation techniques, including clay typing and the estimation of total organic carbon content.

The detector design and tool geometry maxmize the detector count rate and allow highly precise measurements of K, U, and Th elements in the surrounding formation.

The data from SpecStar service can be used in real time to identify the most productive zones of the reservoir with clay-volume analysis or to increase the reservoir understanding with clay typing techniques.



  • High-quality, real-time measurements of K, U and Th concentrations in the formation
  • Real-time borehole images based on total gamma ray binning and elemental concentration quadrants
  • Clear visualization of results
  • Rated for operation up to 329°F (165°C) and 25,000 psi (172 MPa)

Drill to produce

  • Improve well placement accuracy and maximize reservoir contact by geosteering with the visual and intuitive Briggs color cube presentation
  • Reduce uncertainty by easily distinguishing between formation layers with different combinations of K, U and Th concentrations

Enhance reservoir understanding

  • Improve petrophysical evaluation in real time and identify the most productive zone of the reservoir with accurate clay volume calculation
  • Increase knowledge of depositional environment and stratigraphy with accurate clay typing 

Reduce well time

  • Identify the optimum target zone, maintain position within it, and avoid unplanned sidetracks easily


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