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Whenever you find
appreciable quantities of gas in the barrels of Reciprocating pumps, you’ve got
the potential for related problems of gas lock and/or fluid pound….
the loss of production and heavy damage to equipment. For a better understanding
of the solution, let’s examine these problems and how they occur. In normal operation, the
pump barrel alternately fills with fluid through a standing valve below … then
empties into the production tubing by means
of a traveling valve above both valves which are of the ball-and-seat type. In the upstroke, the barrel
becomes a vacuum chamber, opening the lower valve to admit fluid, while the
upper valve is closed under the weight of the
fluid above it. On the downstroke, hydraulic
pressure in the barrel will seat the lower or standing valve and open the
traveling valve, so that fluids in the barrel must
exit through the upper valve … ready to be lifted on the next upstroke.
Simple, effective
hydraulics? Certainly! … until gas appears in the product and the mixture
becomes compressible. At that point, pump efficiency begins to
fade. You’re now pumping less fluids than the well is capable of producing.
GAS LOCK:
Becomes
complete when the product in the pump barrel becomes so compressible that the
traveling valve can no longer open under the weight
of fluids in the tubing above it. The valve remains closed through the entire
downstroke. Operating costs remain the same, but
there is no production.
FLUID POUND:
Occurs
when the ratio of gas to fluid is such that the product in the pump barrel is
compressible during part of the downstroke, hydrostatic
pressure of the fluids in the production tubing will hold the traveling valve
closed during compression, while the rods and pump
plunger gain momentum. Suddenly, the traveling valve “pounds” into the gas/fluid
interface or the point of non-compressibility.
Tremendous, jarring stresses are transferred throughout the system, eventually
resulting in severe damage to rods, tubing,
gearbox, bearings, and structural components of the pumping unit. Costly
replacements become frequent.
… Solves double problems: Wherever gas intrusion poses
problems in reciprocal pumps, more and more field foremen and production
engineers are discovering the single best solution:
The Equalizer. In thousands of field applications, The Equalizer has
delivered the following results consistently
.Dramatic increases in
production
.Reduced equipment damage
.Longer runs between
pulling jobs
.Lower overall operating
costs
Despite its comparatively low
cost, here's a unit that works—and keeps working—where competitive tools fail.
Here’s how … and here’s why …
The Equalizer:
Is best
described as a “lost-motion coupling device” with just one purpose: to
open the traveling valve at or near the beginning of the
pump’s downstroke for peak efficiency. It embodies a “slack joint” or sliding
keeper sleeve, which allows the piston sleeve and port
sub to be fully extended on the upstroke or fully compressed on the downstroke. At the instant the pump
starts downward, you have three distinct mechanical forces combining to open the
traveling valve by means of a push-rod beneath
the ball: (1) inherent upward inertia of The Equalizer’s lower assembly
beneath the keeper sleeve, (2) friction between the piston
sleeve and the pumps barrel wall, and (3) the force of the product against the
port sub. In most applications, these
forces will open the valve at or near the start of the downstroke. If, however,
a large amount of compressible product is
present in the barrel, The Equalizer acts as a shock absorber to open the
traveling valve before “pounding” occurs. It should
never be necessary to “tag the pump” or set it to “bump button”
INSTALLATION IS SIMPLE
The Equalizer:
May be
installed on any stationary-barrel pump with a single traveling valve. (A
slightly different configuration is available
and easily installed on pumps with multiple traveling valves. Call for details.) The
standard model equalizer is designed to
work with API parts. Modifications must and can be made for non-API parts, such
as “California valve seats.”
The Equalizer:
Has
proved equally successful at all depths. Wherever a reciprocating pump is
subject to gas-impairment problems, it will operate
more efficiently with The Equalizer installed. The unit is
available to fit all standard pump sizes, 1-1/16” through 2-3/4”, and
in non-standard sizes on request.
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