Transcript Training in Oil & Gas Production for BP Technical Interns Section 6 – Sucker Rod Pumps Looking at the hows and whys.

Training in Oil & Gas Production for BP Technical Interns
Section 6 – Sucker Rod Pumps
Looking at the hows and whys of
producing fluids from a well using
sucker rod pumps.
Training in Oil & Gas Production for BP Technical Interns
Section 6 – Sucker rod pumping
Sucker rod pumping is the most common means
of artificial lift used by the oil and gas
production industry.
It is simply a matter of using a positive
displacement piston pump to bring produced
fluids to the top of the well using a string of
sucker rods and a string of tubing.
Training in Oil & Gas Production for BP Technical Interns
Understanding pump motion
•Reciprocating horses head.
•Bridle attaches to polish rod.
•Stuffing box isolates rod.
•Polish rod attaches to top of rod
string.
•Rod string attaches to top of pump.
•Fluid travels through pump and to the
surface through the tubing.
Training in Oil & Gas Production for BP Technical Interns
All rod pumps have
A traveling valve
A plunger (piston)
A barrel or tube
A pump chamber
A standing valve
A seating assembly
Training in Oil & Gas Production for BP Technical Interns
3 common rod pumps
Tubing pump
 Barrel is integral part of tubing string
 Plunger attaches directly to rod string
 Stationary tube insert pump
 Tube stationary, plunger moves
 Traveling tube insert pump
 Tube moves, plunger stationary

See Figure 1-1 on page 3.
Training in Oil & Gas Production for BP Technical Interns
Pump applications
Tubing pump
 May be higher volume than insert pump.
 Stationary tube insert pump
 Better for gaseous fluids.
 Better for over 5,000 feet deep.
 Traveling tube insert pump
 Better for handling moderate sand & grit.

Training in Oil & Gas Production for BP Technical Interns
Fluid flow through pump
Fluid flows up through traveling valve
Fluid is trapped in pump chamber
Pump begins downstroke movement
Fluid is trapped in pump chamber
Fluid flows through standing valve
Fluid flows into bottom of pump
Pump begins upstroke movement
See Figure 1-2 on page 6.
Training in Oil & Gas Production for BP Technical Interns
Polish rod stroke
Determined by the design of the
pumping unit.
 May be changed by adjusting
physical parameters of the pumping
unit.
 Polish rod stroke and pump stroke
are not the same.

Training in Oil & Gas Production for BP Technical Interns
Strokes per minute (SPM)

SPMs are determined by
 Speed of the prime mover on the
pumping unit.
 Diameter of sheave on the prime
mover.
 Design parameters of the pumping
unit gear box.
Training in Oil & Gas Production for BP Technical Interns
Practical maximum SPMs
10 SPMs with 320” PR stroke
 12 SPMs with 235” PR stroke
 15 SPMs with 150” PR stroke
 17 SPMs with 130” PR stroke
 20 SPMs with 84” PR stroke
 25 SPMs with 54” PR stroke

Training in Oil & Gas Production for BP Technical Interns
Use non-synchronous motion
Movement of a sucker rod string develops
harmonic vibrations in throughout the rods.
 Synchronous motion of the rod string
causes the vibrations to collide.
 Synchronous motion should be avoided
since it can lead to pre-mature rod failure.
 Non-synchronous motion is desired.

Training in Oil & Gas Production for BP Technical Interns
Non-synchronous calulations
237,000 / Depth /numeric factor = SPMs

237,000 is a constant

Depth is depth of the pump

Numeric factor is either 1.5, 2.5, 3.5, 4.5

Synchronous vibrations are less of a
problem at very slow SPMs.
Training in Oil & Gas Production for BP Technical Interns
Understanding stretch 1
Sucker rods stretch during pumping
thereby decreasing pump stroke (PS).
Unanchored tubing stretches during
pumping thereby decreasing PS.
Overtravel (rubber band effect)
increases pump stroke.
Overtravel decreases as SPMs decrease.
Training in Oil & Gas Production for BP Technical Interns
Understanding stretch 2
Tapered rod strings help decrease the
stretch inherent to sucker rods.
Larger diameter rods go at the top of
the rod string.
Smaller diameter rods go at the bottom
of the rod string.
Rod body diameters: 1, 7/8, 3/4 & 5/8”.
Training in Oil & Gas Production for BP Technical Interns
Calculating pump stroke
Sp = Spr + Sg – Sl

Sp = plunger stroke

Spr = polish rod stroke

Sg = overtravel (See page 19)

Sl = loss of stroke (See pages 20-25)
Training in Oil & Gas Production for BP Technical Interns
Stoke loss in well servicing
When putting a well back to pump after
being serviced, a change in tubing and/or
rods may cause a change in the spacing of
the pump.
 The pump needs to be spaced so that stroke
loss does not cause the pump clutch surface
to begin hitting as the tubing fills with fluid.

Training in Oil & Gas Production for BP Technical Interns
Other sucker rod pumping issues
•Volumetric efficiencies, less than 80%
•Corrosion of pump, rods, and tubing
•Sand, grit, and fluid erosion, page 31
•Rod and tubing wear, pages 32-33
•Gas interference problems
•Gas lock, pages 36-38
•Gas anchors, pages 39-40
Training in Oil & Gas Production for BP Technical Interns
Understanding pump off
Fluid in pump chamber decreases
Volume of fluid continually decreases.
Fluid flow into pump decreases
Traveling value hits top of fluid in the
pump chamber causing a pound.
This is called fluid pound.
If pump continue to stroke without
fluid, friction and heat damage the pump.
Training in Oil & Gas Production for BP Technical Interns
This product was funded by a grant awarded under the President’s High
Growth Job Training Initiative as implemented by the US Department of
Labor’s Employment and Training Administration. The Information
contained in this product was created by a grantee organization and does
not necessarily reflect the official position of the US Department of
Labor. All references to non-governmental companies or organizations,
their services, products, or resources are offered for informational
purposes and should not be construed as an endorsement by the
Department of Labor. This product is copyrighted by the institution that
created it and is intended for individual organizational, non-commercial
use only.