The Technology

The Quad Neutron (Trademarked and Patented) is a four detector nuclear measurement tool specially designed for through pipe reservoir evaluation. Two sets of detectors are positioned around a removable AmBe neutron source and housed in a 43mm OD down hole logging assembly called a Quad Neutron Tool (QNT), or “Quad”. Also in the Quad tool string are several supporting detectors. These include: Natural Gamma Ray, Split Spectrum Gamma Ray, CCL, Top and Bottom Temperature, Fluid Resistivity, and an Accelerometer.  The Quad data bus and modular connector configuration enables attachment of many other detectors to be accommodated for specific applications.

Designed and Tested to 150C and 15kPSI, the Quad has application in harsh environments and many wellbore configurations.  The Quad’s complex measurement suite is delivered with a simple telemetry and lower power requirements. It easily interfaces to e-line surface connections (Warrior service) or Roke’s own down-hole memory tools.  Slim hole memory capability and through pipe measurement capability enables flexibility in Quad deployment:

1.  Standard e-line

2.  Slickline memory

3.  Drill pipe or tubing deployed on memory

4.  Coiled Tubing (both e-coil and memory)

5.  Slickline smart release on memory

6.  Surface release system on memory

Specific deployment options in your area are available on the Operations page.

The standard log presentation is the Quad Litho Log and below are just some of the interpretable parameters:

•  Porosity including clay free porosity

•  Saturation including the ability to differentiate between fresh water and heavy oil

•  Clay Volume

•  Relative Permeability

•  Relative Bulk Density

•  Dolomite identification in carbonate reservoirs

•  Pyrite and calcite identification in clastic formations

•  Differentiation between bitumen and moveable oil


To fully appreciate the Quad and the lithology presentation(s), it is important to become familiar with several key concepts that govern the Quad measurements and presentation.  These are generally described in the physics page, or contact your local representative for more detail.


Once understood, the Quad Technology becomes a powerful and elegant tool. But the real test is results of real applications. A review of our collection of case histories reveals empirical Quad success where Open Hole, Pulse Neutron, Thermal-Epithermal Neutron, Dielectric, and Carbon/Oxygen measurements have been indeterminate.