Page 82 - Drilling Technology in Nontechnical Language
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Chapter 3 – DRILLING A LAND EXPLORATION WELL 73
Fig. 3–20. Logging truck running logs into a land well
Logging is quite expensive, and not just in the cost of the rig time taken.
The logs themselves can be very costly to run. Some logging tools cost in
excess of a million dollars, so it is vital not to lose one down the hole!
Logs run in the intermediate hole section will typically try to establish
the following information:
▪ Formation tops and thicknesses
▪ Formation lithology, porosity, pore fluids salinity, and presence of
any hydrocarbons
▪ Continuous hole profile, showing the diameter in two directions
(so that an overgauge hole that is enlarged more in one direction
than the other can be recognized)
▪ Formation compressive strengths (measured using sound waves,
useful when deciding what drill bits to use on the next well)
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