The original logging tool, the SP Sub allows lithology identification and can be used as a means of log correlation. Use the SP Sub to determine bed boundaries, indicate porosity and permeability, and measure the difference in potential between the downhole electrode and a surface electrode.

MECHANICAL:

LENGTH 2.96 ft (.09 m)
DIAMETER 2.25 in (57 mm)
WEIGHT 10.2 lbs (4.62 kg)
PRESSURE RATING 20,000 psi (140 Mpa)
TEMP RATING 350 °F (175 °C)
TENSILE STRENGTH 65,000 lbs