Conductor Casing
Surface Casing
Drilling Mud
30 - 60
feet deep
Intermediate Casing
Drilling Mud
500 - 1,500
This layer
feet deep
runs from
the surface to
at least 20 - 50 feet
below useable quality
ground water.
Production Casing
5,000 - 10,000
feet deep
An example of
well casing in Texas.
Graphic Courtesy
of Texas Oil and
Gas Association,
Copyright 2010