Setting Casing in an oil well.
- First there is the drive pipe or conductor pipe. It is about 30 inches in diameter. It is driven into the ground by a large single piston engine. This is like a big hammer... boom, boom, boom. This pipe is hammered 30 to 300 feet into the ground depending on how consolidated the sediments are (how hard the rock is).
- Then the mud is washed out of the drive pipe, then more hole is drilled with a smaller drill bit (typically 24.25 inches). Then an intermediate casing string is set. This pipe is typically 24 inches in diameter> Thirty foot sections are screwed together and lowered down into the hole until they reach the total depth of the well. This pipe is cemented in place, the cement in the pipe is drilled out, the bottom of the pipe is drilled through (the casing shoe) and drilling continoues.
- More hole is drilled, perhaps with a 12.25 inch bit. 10 inch casing is set in the same method as the previous pipe.
- In the end, we end up with a series of telescoping tubes each extending further and further down into the earth.
activity is demonstrated in the VRML animation below. Click on the big red
cylinder (drive pipe) to start the animation.
Vizx3d file for those interested.
Created on ... September 22, 2003