
231
I
Irreducible Water Saturation
Invert Mud: Water-in-oil emulsion muds. There may be as much as 50%
brine in the liquid.
I/O: See Input–output.
IOGCC: Interstate Oil and Gas Compact Commission.
Ion: An atom, or molecule, that has lost or gained one or more electrons.
Ion Exchange: Ion exchange (cation or anion) where scaling or water harden-
ing minerals such as calcium and magnesium are removed by substitution
for sodium.
Ionic Bond: A bond formed by an atom that has a strong tendency to lose
electrons with an atom with a strong tendency to accept electrons.
Ionization: The process of adding electrons to, or removing electrons from,