Pump and Fluid Systems
Chapter 5: Assembly/Disassembly
weatherford.com
30
MP-16 2-Piece 5000 psi January 2013
4.3.4
Pistons & Crosshead Extension Lubrication
The lubrication of the pistons and crosshead extensions is accomplished using an electric
pump which directs a stream of lubricating fluid onto the pistons and liners in a regulated flow.
Normally, this fluid is simply clean water, but it is recommended that a synthetic fluid (Castrol
Syntilo 9954 or equivalent is recommended) or water-soluble oil be added, depending on the
corrosiveness of the water and the drilling fluid. A mixture consisting primarily of clean water
with 10-20% synthetic fluid or water-soluble oil is recommended, with precise values to
depend on drilling conditions, size of the liner spray wash volume tank and the liner spray
pump manufacturer’s guidelines.
If only clean water is used, the operator must exercise greater than normal care and
maintenance in order to prevent heat and corrosion damage in those parts in or adjacent to
the liner piston chambers. Coating clamps and all exposed surfaces with a thread compound
will minimize the effects of corrosion.
Used lubricant accumulates in compartmentalized sumps beneath the connecting rods,
where it is re-circulated by the lubrication system. These sumps should be cleaned any time
the oil is changed.
4.3.5
Temperature Maintenance
The oil temperature should be continuously monitored during operations, and it is
recommended that a high temperature alarm system is employed to warn of extreme
temperature fluctuations. In extreme conditions, a heat exchanger may be needed to keep
the crankcase temperature below 180°F (82°C).
NOTE
Effective cooling of the pistons and liners can only be accomplished if the temperature
of the coolant is below that of the drilling fluid. Under certain circumstances, an
external cooling system may be required to remove heat from the coolant fluid.