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J
J
J: Productivity index.
Jack: An oil well pumping unit that operates with an up-and-down, or
seesawing, motion; also called a pumping jack.
Jack (Beam Lift): Usually a pump jack, operating the rods in a lift and fall
motion.
Jacket: The steel lattice structure that supports an offshore platform.
Jacket Platform: (1) An offshore platform constructed entirely of steel. Such
platforms generally are held in position by long steel piles driven deep into
the seabed. (2) The steel support structure from the sea oor to the top sides.
Jack Knife Rig: A rig with a folding mast that can be lowered and raised
relatively quickly.
Jack-Up Drillin ...