
289
N
Nonattainment Area
More information on the Nobel Prizes can be found on their website: http://
www.nobel.se/.
Nodal Analysis: A pressure drop vs. ow study, using a computer program
that compares ow performance at various “nodes” along the ow path.
Nodding Donkey: A rod pump surface unit—pump jack.
Node: A reference point in the well.
NOEL: No-observed-effect level.
No Go: A prole ring in the tubing with a very small opening that allows
ow but stops any equipment or tool from passing through the restriction.
May be small ID or pinned.
NOI: See Notice of intent.
Noise Log: A sound recording downhole. The best performance of noise logs
is