QL40-CAL
from Mt Sopris

The QL40CAL sub records a continuous borehole diameter log using three mechanically coupled arms in contact with the borehole wall. This 3-arm caliper measurement serves as a useful initial log to assess borehole conditions before deploying more specialized or costly probes, including those with radioactive sources.

The caliper arms are controlled from the MATRIX LoggerSuite application at the surface, allowing the probe to be lowered with the arms closed. Once positioned at the bottom of the borehole, the arms are opened, and the spring-loaded arms adjust to variations in borehole diameter as the probe is raised.

Other QL probes commonly stacked with the QL40CAL include the QL40GR (Natural Gamma), QL40RES (Multi-point Resistivity), QL40IP (Induced Polarisation), and the QL40FTC (Temperature & Fluid Resistivity)

Operating Conditions

W - Water √
M - Mud √
D- Dry √

S - Steel √
P - PVC Borehole √
UC- Uncased √