E v K p. it v, vS vP / vS
E l aStl C Youngs modulus Poissons ratio Bulk modulus Shear modulus First Lam parameter P - velocity 5 - velocity VP I \I5 ratio
[GPa] [dimensionless] [GPa] [GPa] [GPa] [m/s] [m/s] [dimensionless]
pa ra m Ste rS a.k.a. o a.k.a. i
. Normally synonymous with a neutron porosity log. However, the
term is sometimes broadened to include an activation log.
Measures hydrogen content
Resistivity: the resistance to the passage of an
Conductivity: the ability to conduct an electric
Effect of Clay
Cation Exchange Capacity (CEC)
A type of acoustic log that displays
traveltime of P-waves versus depth. Sonic
logs are typically recorded by pulling a tool
on a wireline up the wellbore. The tool
emits a sound wave that travels from the
source to the formation and b
The Caliper log
A representation of the measured
diameter of a borehole along its depth.
Caliper logs are usually measured
mechanically, with only a few using sonic
devices. The tools measure diameter at a
specific chord across the well.
Bit size = diameter
Reference level (1)
Feet below Kelly Bushing
The kelly bushing connects the kelly to the rotary table.
This hexagonal kelly turns the entire drillstri
Wireline logs www.agi|egeoscience.com 7&in
11 in m
l'll E i a-
3 8 e 2, 3. 5.
Log Name Measures Units Range typical Precision Vertical Depth of 8 g a :3 g 1, 3 Quality Tool names and Mud Casing 23 Ln m
plot range resolution investigation 3 g 5' it: 8 5
A common and inexpensive measurement of
the natural emission of gamma rays by a
formation. Gamma ray logs are particularly
helpful because shales and sandstones typically
have different gamma ray signatures that can be
Mass per unit of volume. Density is typically
reported in g/cm3 (for example, rocks) or pounds
per barrel (drilling mud) in the oil field.
Emmits gamma ray