
317
P
Pilot Hole
PHPA: Acrylamide polymer mud.
Physical Contract: A natural gas contract where delivery and receipt are
expected.
Physical Waste Treatment Process: Physical waste treatment processes
include the use of racks, screens, comminutors, clariers (sedimentation and
otation), and ltration. Chemical or biological reactions are important treat-
ment processes but not part of a physical treatment process.
PI: See Productivity index.
Pi Bond: A chemical bond formed by the indirect overlap of two atomic
orbitals. “I don’t think I actually want to get into this, but the two bonds in
a double bond are not the same;