Selecting a subsurface pump for a beam pumping system is a matter of estimating the pump displacement that corresponds to a desired production rate, and then determining the optimal combination of stroke length, pump speed and plunger diameter for this displacement. Once the pump is sized, we can consider what type of pump is most appropriate for the given set of operating conditions.

Tanya – yunianto wiryongadiyo

Bapak2,

Kebetulan masih awam dalam masalah pompa,
Mohon pencerahan mengenai effisiensi pompa.

Apakah efisiensi pompa = actual prod. pompa/teoritical volumetric dari pompa (dia^2*Stroke lenght*SPM*0.1166)?

Jika dibandingkan tabel API Bull 11L3 (production unanchored), teoritical volumetric dari pompa tidak relevan dengan yang ada di tabel,

Mohon pencerahan

Tanggapan 1 – Zein Wijaya

Mas Yunianto,

Berikut sekilas contoh ttg perhitungan effisiensi pompa

Mudah mudahan bisa membantu..

Pak Budhi karena format equation tidak beraturan kalau saya kirim langsung ke milist..mohon bantuan untuk mendistirbusikannya dalam bentuk MS Word

Terima kasih

SUBSURFACE PUMP SELECTION

Selecting a subsurface pump for a beam pumping system is a matter of estimating the pump displacement that corresponds to a desired production rate, and then determining the optimal combination of stroke length, pump speed and plunger diameter for this displacement. Once the pump is sized, we can consider what type of pump is most appropriate for the given set of operating conditions.

Pump Displacement Requirements

A subsurface pump displaces a volume defined by its stroke length, pump speed (strokes per minute), plunger diameter and volumetric pump efficiency:

(1)

PD = 0.1166 S p N D 2 E p

where PD = pump displacement at 100 percent volumetric efficiency, B/D

S p = effective plunger stroke length, inches

N = pumping speed, strokes/min

D = plunger diameter, inches

Ep = volumetric pump efficiency.

This quantity is usually less than 1.0 for the following reasons:

Leakage of fluid around the plunger—The volume of fluid that slips down around the plunger during a pump stroke, and thus is not actually displaced, is known as slippage.
Foaming of the fluid within the pump—When this occurs, the pump becomes less efficient because it not only displaces fluid but also compresses the gas phase of the foam.
Shrinkage of the fluid—The fluid pressure and temperature decrease it is produced to the surface. This causes gas to come out of solution and the volume of the produced liquid to shrink by a factor corresponding to the formation volume factor at the pump depth.

Local operating conditions determine the pump efficiency, which is typically in the range of 70 to 80 percent.

Stroke Efficiency (Es)

The effective stroke length (Sp) in Equation 1 is the stroke length at the pump. Because of rod stretch and contraction, acceleration and inertial effects, Sp will be considerably shorter than the polished rod stroke length measured at the surface.

For our initial pump sizing determination, we may define the stroke efficiency (Es):

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