1. Long & Slow vs. Short & Fast
Title slide
Keep the title brief and to one line?
The second line (in smaller type style) is for the date of the presentation – depending on your presentation, you may also need to include Location and/or Presenter’s name/s and Job title if needed – as a such a second line may be used for these purposes.
Do not include unnecessary information in your presentation title – starting off with clear and simple messages will set the style and focus the audience for what is to follow.
Norman W. Hein, Jr., P. E. – President & Managing Director
Oil & Gas Optimization Specialists, Ltd. (OGOS), Midland, TX.

2. 2005 Beam Pumping Workshop - ©OGOS
Let’s Vote
How should pumping units be operated?
Long & Slow?
Short & Fast?
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

3. 2005 Beam Pumping Workshop - ©OGOS
Is There a Preference?
YES!
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Oct , 2005

4. 2005 Beam Pumping Workshop - ©OGOS
Content
Speed Background
Acceleration Factor
Theoretical Max Speed
Pumping Unit Rating
API Spec
Lufkin Recommendation
Gear Box
Pumping Unit
Fatigue Effects
Well Design Examples
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

5. 2005 Beam Pumping Workshop - ©OGOS
Speed Background
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

6. Speed Background (con’t)
Acceleration Factor
C = (S * N2)/70,500
Don’t exceed free fall speed of the rods
1962 W. H. Ritterbusch “Petroleum Production Handbook”
“Always choose a speed below that maximum practical limit permitted by free-rod fall so that the polished-rod clamp and hangar bar will not separate on the downstroke.”
Recommended permissible speed of 70% of maximum free fall limit.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

7. Speed Background (con’t)
1965 Bethlehem Steel published “Pumping Unit Selection Charts”
“Normally at speeds which exceed 0.7 of the free fall velocity, the polished rod begins to leave the carrier.”
Lufkin in catalog supported 0.7 of free fall speed (for Conventional Unit geometries)
10% reduction if Air Balance
20% reduction if Mark II
If well straight and pumping fresh water, C = 0.417
But seldom is well straight
Typically pumping other than fresh water
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

8. 2005 Beam Pumping Workshop - ©OGOS
SPM vs. S
S (in.)
Velocity PR (fpm) 16
42.9
36.4 97 24 35
29.7
119 30
31.3
26.6
133 36
28.6
24.2
145 42
26.5
22.7
157 48
24.7 21
168 54
23.3
19.8
178 64
21.4
18.2
194 74
19.9
16.9
208 86
18.5
15.7
225
100
17.1
14.5
242
120
13.3
266
144
14.3
12.1
291
13.2
11.2
315
192
12.4
10.5
336
216
11.7
9.9
356
240
11.1
9.4
376
300
8.4
420
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

9. Speed Background (con’t)
Gipson & Swaim recommended for design:
0.225 < C < 0.3 (Shallow wells)
> optimize equipment (not too large)
< 0.3 to stay less than free fall speed
N/No’ <0.35 (Deeper wells)
Gipson & Swaim has always recommended designing PU based on middle stroke for unit.
In real world operating situation, the free fall speed of the rods and the gear box capacity determine maximum pumping speed.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

10. 2005 Beam Pumping Workshop - ©OGOS
Pumping Unit Rating
API Spec 11E “Pumping Units” covers
Gear Reducer (Box)
Unit Structure
Gear Reducer performance based on AGMA Standard
Originally based on 20 SPM for all gear reducers
IN 1981, API revised reducer rating for 456 & larger units
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

11. Pumping Unit Rating (con’t)
API larger unit speed rating:
Peak Torque Rating (in-lbs) SPM 456,
640,
912,
1,280,
1,824,
2,560,
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

12. Pumping Unit Rating (con’t)
Lufkin Hi-Q Herringbone Gear Speed Reducers – Double Reduction Units
Assume operation ~1150 rpm prime mover
~30 to 1 ratio
D D
D D
D D
D D
D D
D D D
*assumes prime mover speed of 870 rpm
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

13. Pumping Unit Rating w/Structure
Pumping Unit Size Max. SPM PU Size Max. SPM
C (305) C
C (305) C
C C
C C
C C
C C
C C
C C
C C
C C
C C
C C C
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

14. Pumping Unit Rating w/Structure
Pumping Unit Size Max. SPM PU Size Max. SPM
M M
M M
M M
M M
M M
M M
M M
M M M M
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

15. Pumping Unit Rating w/Structure
Pumping Unit Size Max. SPM PU Size Max. SPM
A A
A A
A A
A A
A A
A A
A A
A A
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Oct , 2005

16. Pumping Unit Rating w/Structure
In real world operating situation, the
free fall speed of the rods and
the Pumping Unit Stroke Length determine maximum
pumping speed.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

17. Fatigue Effects (F. V. Lawrence)
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18. Fatigue Effects (Con’t)
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Oct , 2005

19. Fatigue Effects (Con’t)
API RP 11BR discusses Modified Goodman Diagram (MGD)
Based on R. R. Moore fatigue (1920s)
Assumed 10 Million Cycles life (10spm*24hr/day) = 23 months ~2 years)
1993 Hein & Hermanson published SPE “New Look at Sucker Rod Fatigue Life”
Provided history of development of MGD
RP 11BR MGD conservative
Non-linear approach (Gerber Parabolic Relation) may be more appropriate
Overloaded rods (~125%)
50,000,000 Cycles (10spm *24hr/day = 115 months ~10 years)
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

20. Fatigue Effects (con’t)
API RP 11L “Design Calculations for Sucker Rod Pumping Systems:
PPRL = Wrf + [(F1/Skr) * Skr]
MPRL = Wrf – [(F2/Skr) * Skr]
PT = (2T/S2kr) * Skr * S/2 * Ta
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

21. 6 Basic Loads & Load Range
LOAD RANGE represents the load range between the peak and minimum polished rod loads. Load ranges are used in calculating max and min sucker rod stresses.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

22. Fatigue Effects (con’t)
Load Range (PPRL – MPRL) thus effects cumulative stress (strain) damage
Smaller load range
Longer fatigue life
Less work
Less HP
Larger load range
Shorter fatigue life
More work
More HP
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

23. 2005 Beam Pumping Workshop - ©OGOS
Well Design Example
One main criteria for rod string design is to match pump displacement to well production capacity.
PD = * S * N * D2
WC/0.85 < PD < WC/0.65
OR PD = ~120% to ~150% * WC
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

24. 2005 Beam Pumping Workshop - ©OGOS
Well Design Example
Used Beam Pump Program
Assumed Well:
H=L= 5000’
4940’
D = 1.5”
65 - D grade rods
G = 1.0
0 sinker bars
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

25. Well Example – results summaryN
Fo/SKR
N/No' Sp PD SV TV
PPRL
MPRL
PTpr
HPpr 74
7.7
0.2868
0.1414
56.0
113.1
5852
9677
10,992
4,714
135.4
4.5
9.8
0.1800
58.4
150.1
11,336
4,190
147.7
6.0
12.3
0.2315
60.8
200.9
11,850
3,605
165.2
8.7 86
6.4
0.2467
0.1176
67.0
113.2
11,002
4,914
138.1
8.3
0.1525
69.2
150.6
11,358
4,446
174.7
6.1
10.6
0.1947
72.1
200.5
11,801
3,792
196.4
8.5
100
5.3
0.2122
0.0973
81.3
113.0
11,001
5,055
182.0
4.4
7.0
0.1286
82.6
151.7
11,389
4,660
201.6
9.0
0.1653
84.7
200.0
11,825
4,049
228.6
8.4
168
2.9
0.1263
0.0532
148.0
112.8
10,662
5,407
268.0
3.9
0.0707
148.9
150.4
11,064
5,169
286.7
5.1
0.0938
149.8
11,567
4,821
317.4
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

26. Well Example (constant production)
Fo/Skr
N/No' Sp PD
PPRL
MPRL
Load Range
PTpr
HPpr 74
9.8
0.2868
0.1800
58.4
150.1
11,336
4,190
7,146
147.7
6.0 86
8.3
0.2467
0.1525
69.2
150.6
11,358
4,446
6,912
174.7
6.1
100
7.0
0.2122
0.1286
82.6
151.7
11,389
4,660
6,729
201.6
120
5.6
0.1768
0.1030
101.9
149.9
11,304
4,897
6,407
229.1
144
4.6
0.1473
0.0839
125.2
11,180
5,052
6,128
257.5
168
3.9
0.1263
0.0707
148.9
150.4
11,064
5,169
5,895
286.7
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

27. 2005 Beam Pumping Workshop - ©OGOS
Summary
Long & Slow has been sold as way to reduce fatigue failures due to less cycles.
Short & fast vs. long & slow are relative terms.
Fatigue theory shows load range most important to fatigue life.
1920’s fatigue life of 10,000,000 cycles not represent current rod manufacturing and well optimization. 50,000,000 cycles should be obtainable. (FF ~0.10)
Typically for same production, same work required to lift to surface, so ~PPRL and HPpr same until very long stroke.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

28. 2005 Beam Pumping Workshop - ©OGOS
Summary (con’t)
As S increases MPRL increases due to dynamic effects which reduce load range.
While longer/slower may reduce load range, PTpr and required PT for unit increased.
Slowing down long S design may be problematic since efficiency reduces for smaller sheaves.
Jack shaft may be used to provide additional speed reduction, but further reduces power transmission efficiency and increases costs.
Sinker bars will provide same dynamic effect of increasing MPRL and reducing load range for shorter/faster operation.
Optimization of pumping equipment might say ‘shorter/faster’ w/ sinker bars is more operational effective.
2005 Beam Pumping Workshop - ©OGOS
Oct , 2005

29. Long & Slow vs. Short & Fast
Norman W. Hein, Jr., P. E. – President & Managing Director
Oil & Gas Optimization Specialists, Ltd. (OGOS), Midland, TX.
Title slide
Keep the title brief and to one line?
The second line (in smaller type style) is for the date of the presentation – depending on your presentation, you may also need to include Location and/or Presenter’s name/s and Job title if needed – as a such a second line may be used for these purposes.
Do not include unnecessary information in your presentation title – starting off with clear and simple messages will set the style and focus the audience for what is to follow.

30. 2005 Beam Pumping Workshop - ©OGOS
Oct , 2005