VARIABLE SLIPPAGE PUMP®

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Dover Artificial Lift, part of Dover

Energy, is a team of industry-leading companies that utilize their collective

resources to help oil & gas producers optimize revenues, profitability,

safety and environmental compliance through high-quality

production, completion, gathering and control systems.

Dover Artificial Lift delivers the latest technologies, innovations and

solutions in rod lift, plunger lift, gas lift, hydraulic lift, progressing cavity

pump, surface production equipment, well site controls and analytic

tools. Our expanding production offering consists of brands with industry-

leading quality, performance and reputation.

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Designed specifically to prevent the production-halting, and revenue-damaging, gas lock condition in pumping systems

Increased minimum polished-rod load allows for greater sucker-rod life, a reduction in necessary interventions and greater pump uptimes

Available in abrasion and corrosion-resistant materials and coatings, to ensure maximum product durability and lifespan

Equalize Pressure. Eliminate Gas Lock. Enhance Production.

Variable Slippage Pump® (VSP)

Harbison-Fischer® is the global leader in downhole reciprocating pumps

and related equipment for the upstream oil and gas market. We are proud to be the

industry leader in service, quality and technology for more than seven decades.

The patented Variable Slippage Pump

is a sucker-rod-drawn, positive-

displacement pump which operates on

the principle of pressure equalization just

before the plunger reaches the top of

the upstroke.

Existing pump designs rely on the ability

of the pump to produce high pressure

in the compression chamber during

the downstroke. This high pressure is

needed to open the traveling valve and

allow fluid and gas to flow through the

plunger for lifting to the surface on the

upstroke. Failure of the traveling valve to

open on the downstroke in gassy wells

causes a gas locked condition and no

production.

The VSP has a gradual taper in the

upper barrel. As the plunger enters

this taper near the top of the upstroke,

slippage increases past the plunger,

and pressure is equalized above and

below the plunger and traveling valve.

As a result, when the plunger starts

downward, the traveling valve opens

easily since high pressure in the

compression chamber has already been

achieved.

The Variable Slippage Pump® Advantage

OUR SOLUTIONPAIN POINTS

The VSP actively counteracts gas lock and gas pound during its normal operation by allowing a small amount of fluid to slip back down the pump on its upstroke. This fluid mixes with any gas in the pump, equalizing pressure, and allows the pump to compress fluid effectively. While this fluid slippage slightly decreases maximum production, it allows for a steadier production rate, and higher net production.

RESULTS

By actively combating gas lock and gas pound, the VSP promotes steady, consistent production, a higher average production rate, and increased well profit. This is especially true in gassy well environments, which face substantial risk of inefficient or halted production due to gas lock.

Gas lock and gas pound, which are common conditions in gassy well environments, can greatly reduce or even stop a well’s production. When gas enters a pump, it cannot effectively compress fluid on its downstroke, which prevents it from being carried to the surface. If fluid cannot reach the surface, production can be inefficient or nonexistent.

Typical pumps aren’t designed to address gas pound or lock. As a result, any gas that enters the pump can accumulate, making it increasingly difficult for the pump to achieve ideal fluid compression, internal pressure or production.

Gas Pound occurs when the level of gas in a pump causes ineffective compression below the plunger. When this gas is compressed to a certain point, it will violently meet with the liquid in the pump, causing a production-damaging hydraulic shock to reverberate through the system.

Gas Lock occurs when so much gas is present below a pump’s plunger that it becomes impossible to achieve proper compression. As a result, the pump’s traveling valve cannot open and production is completely halted.

The VSP is designed to eliminate Gas Pound and Gas Lock conditions

How a Typical Downhole Pump Works

Gas Pound Gas Lock

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LONGEVITY The VSP’s increased minimum load on the polished rod allows for enhanced sucker rod life.

SEAMLESS FIT Industry-standard components allow the VSP to fit into nearly any well and make for a simple installation process.

The VSP’s tapered barrel equalizes in-pump pressure during its upstroke to allow for compression and production, preventing gas lock or gas pound.

EFFICIENCY FOCUSED The VSP is designed to promote steady and consistent production, especially in gassy wells.

CUSTOM BUILT Each VSP pump is built to meet the specific needs of the well in which it will be installed, enhancing product lifespan and efficiency.

CLIENT SATISFACTION Almost 100% of VSP customers re-order the product when the equipment reaches the end of its lifespan or for their other wells.

In typical pumps, gas can accumulate in the cavity below the plunger. This makes it impossible for the pump to compress properly.

In the VSP, fluid is able to slip from above the plunger down into the cavity below. This fluid helps equalize pressure and allows the pump to maintain efficient production.

The tapered barrel at the top of the VSP allows a small amount of fluid to slip back down into the pump during its upstroke. This fluid then enters the cavity below the plunger and mixes with the gas to equalize the pressure in the pump. This allows the pump to maintain compression and steady production.

How the VSP Works

ELIMINATES GAS LOCK & GAS POUND

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Technical Specs

Part Number

Tubing Size & Pump Bore

Item Description No. Req’d. 2-3/8" x 1-1/16" 2-3/8" x 1-1/4" 2-7/8" x 1-1/2" 2-7/8" x 1-3/4"

Plu

nger

Ass

embl

y

1 Bushing, Valve Rod 1 60E2 60K2 60K2 60L2

2 Rod, Valve 1 65E* 65K* 65K* 65K*

3 Coupling, Top Plunger 1 4-84B1 4-84C5 4-84E2 4-84H1

4 Plunger 1 60-252B* 60-252C* 60-252E* 60-252H*

5 Cage, Closed Plunger 1 4-131B2-45 22-903C2-45 22-903E2-45 22903H2-45

6 Ball & Seat 1 2B4 2C2 2E2 2H2

7 Plug Seat 1 1-146B11 1-146C11 1-146E11 1-146H11

Bar

rel

Ass

embl

y

8 Guide, Rod 1 72E1 72E12 72K1 72K1

9 Coupling, Extension 1 527B3* 527C* 527E* 527H*

10 Barrel, VSP® 1 416-5504 416-5501 416-5502 416-5503

11 Barrel 1 426B3* 426C* 426E* 426H*

12 Coupling, Extension 1 527B3* 527C* 527E* 527H*

13 Cage, Closed Barrel 1 22-358E22-45 22-358E22-45 22-358K22-45 22-358K22-45

14 Ball & Seat 1 2H2 2H2 2L2 2L2

Sea

ting

Ass

embl

y, 3

-cup

15 Mandrel 1 95H1 95H1 95L1 95L1

16 Cup, Seating 3 180-190J+30 180-190J+30 180-190L+70 180-190L+70

17 Spacer 2 175H1 175H1 175L1 175L1

18 Locknut 1 156H1 156H1 156L1 156L1

19 Coupling 1 163H21 163H21 163L21 163L21

Sea

ting

Nip

ple Nipple, Seating 1 299K312 299K312 299M312 299M312

Nipple I.D. 1 1.780" 1.780" 2.280" 2.280”

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Variable Slippage Pump® (VSP) pump is available in all standardconfigurations of sucker-rod pumps that are compatible with spray-metal plungers. For severe sand conditions that will stick to the pump it is recommended to use a Top Sand Seal.

* Specify the following:- Barrel length (feet) - Extension length (inches)- Plunger length (feet) and minus size (in thousands of an inch)- Valve rod or pull tube length (inches)

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Tubing Size 2-3/8" 2-3/8" 2-7/8" 2-7/8”

Pump Bore 1-1/16" 1-1/4" 1-1/2" 1-3/4"

Bore Factor .132 .182 .262 .357

Barrel O.D. 1.437 1.625 1.875 2.125

Extension O.D. 1.750 1.750 2.250 2.250

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202.1

To learn more about the Harbison-Fischer Variable Slippage Pump® (VSP), visit: www.doverals.com