1. Well Samples: Sidewall Cores
Small samples
(1 x 2.5 inches)
30 samples per run
Sampling based on logs
Step 1:
Gun in position
Step 2:
Shot fired
Stabilizer
Gun Body
Core Barrels
SLIDE 9
This slide explains what a sidewall core is
The tool (pictured on the left) is part of the drill stem
It has about 30 casings that can be fired into the formation
The casing captures a small sample of rock
The samples are retrieved at the end of a logging run
This does not require very much extra rig time – so is relatively inexpensive
The drawback is that the sample is small – we get the rock type but nothing about vertical variability, sedimentary structures, etc.
Step 3:
Core retrieved
Courtesy of ExxonMobil
L 3 - Types of Data