7th Annual Sucker Rod Pumping Workshop

Renaissance Hotel Oklahoma City, Oklahoma September 27 - 30, 2011

Identify Problems Using Pump Plunger Motion

Lynn Rowlan

Sept. 27 - 30, 2011 2011 Sucker Rod Pumping Workshop 2

Introduction • Animation of dynamometer data helps explain normal

pump plunger motion when the tubing is anchored or unanchored.

• Rods stretch to pickup Fluid Load • Rods also stretch to overcome downhole sticking force • When rod spring force exceeds the friction force the

plunger is suddenly released • Real time analysis is easier when pumping motion is

displayed in time along with the loads and position • Visualization of plunger and polished load, velocity and

position is an advanced tool for troubleshooting the rod pumping system

Dynamometer Card Terminology

Surface Card

Fo – Fluid Load Applied by the Pump to Rod String, from differential pressure (discharge - intake) acting across the pump plunger. Kr – Lbs/in Rod String Spring Constant SKr – Load Required to Stretch Rod String a Length Equal to the Surface Stoke Length Fo/SKr – Fraction of Surface Stroke Lost to Rod Stretch Picking up Fluid Load

Fo Fluid Load

kr

Pump Card Anchored

Tubing 3

Spring Constants Kr & Kt

Pump Card

Kr Surface Card

Pump Card

Unanchored Tubing

kt

Rods Stretch 3.6 X More Than Tubing

Rods Elastically Stretch to Pick Up Fo from A-B & Un-stretch to Release Fo from C-D

Pump Load & Position

Surface Load & Position

Kr

Kr

Rod Stretch = S x Fo/SKr

Until Rods Elastically Stretch to Pick Up Fluid Load Spring

Anchored Tubing – Pump Does Not Move

5

Compare Polished Rod Position to Pump Plunger Position - Anchored Tubing

6 Sept. 27 - 30, 2011

Compare Polished Rod Velocity to Pump Plunger Velocity (Anchored Tubing)

Note: V ≅ 0, Plunger does not move, ….. A-B & C-D ….. Until Fluid Load, Fo, Transferred From SV to TV OR TV to SV

7 Sept. 27 - 30, 2011

Compare Polished Rod to Pump Plunger Position (Un-anchored Tubing)

Kt= 464 Lbs/in

9 Sept. 27 - 30, 2011

0 146.0-5.00

0

5.00

10.00

15.00

20.00

25.00

30.00

134.8

Fo Max Fo From Fluid Level

Wrf

Wrf + Fo Max

Kr

11

Plunger Stops Due to Downhole Sticking

1) Diagnostic dynamometer surface cards used for Diagnosing Sucker Rod Pumping Systems.

2) Pump dynamometer card is to identify and analyze downhole problems.

3) Spike load at 100.2 inches on Stroke #1 shows when the plunger stopped on the upstroke. Unusual shape occurs over a 0.6 second time period and represents 4280 lb load increase required to overcome the downhole friction.

Surface Card

Pump Card

Stick

Tag Sept. 27 - 30, 2011

Polished Rod Moves up 20” to Apply 4280 Lbs Spring Force

F = Kr * X Kr = 214 Lb/in

120”

140” F = 214 x 20 = 4280 Lbs

20”

0.6 Sec

Plunger Position MUST be Flat OR Not Sticking!

12 Sept. 27 - 30, 2011

Polished Rod Moves up 20” While Plunger Stopped 0.6 Sec.

When no longer Stuck Plunger Moves Quickly at Top of Stroke

Plunger Stops for 0.6 Seconds while Polished Rod moves up 20 inches. Applying a 4820 Lb Force, before plunger starts to move.

13 Sept. 27 - 30, 2011

Plunger Stuck 0.6 Sec., Moves 33.5” in 1.1 Seconds After Unstuck

33.5”

Plunger Stuck 0.6 Sec Velocity Goes to Zero

Unstuck

14 Sept. 27 - 30, 2011

Drop in Surface Load Occurs When Plunger Becomes Unstuck and Moves

PR Load Drops when Unstuck

Plunger Moves Quickly

15

Flat Plunger Position on Upstroke Indicates Plunger Stops Due to Downhole Sticking

Sticking, Pump Stops, Rods Stretch, then Plunger Moves

17 Sept. 27 - 30, 2011

0.25 Speed Shows Pump Stop When TV Ball Suddenly Seats on Up Stroke

Pump Stops

Shock Loading at Surface

19

Sept. 27 - 30, 2011 2011 Sucker Rod Pumping Workshop 21

Conclusions 1. Motion of Plunger Impacted by Rod Stretching

to Pickup Fluid Load 2. Downhole Friction also Impacts Plunger Motion 3. Excessive Friction Can Cause Plunger to Stop 4. Sudden Closing of TV Can Also Cause the

Plunger to Stop 5. Animation of Plunger Motion Increases

Understanding of Plunger Motion Impacted by Rod Stretch

Sept. 27 - 30, 2011 2011 Sucker Rod Pumping Workshop 22

Copyright

Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Sucker Rod Pumping Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the Southwestern Petroleum Short Course (SWPSC), rights to:

– Display the presentation at the Workshop. – Place it on the www.alrdc.com web site, with access to the site to be as

directed by the Workshop Steering Committee. – Place it on a CD for distribution and/or sale as directed by the Workshop

Steering Committee.

Other use of this presentation is prohibited without the expressed written permission of the author(s). The owner company(ies) and/or author(s) may publish this material in other journals or magazines if they refer to the Sucker Rod Pumping Workshop where it was first presented.

Sept. 27 - 30, 2011 2011 Sucker Rod Pumping Workshop 23

Disclaimer The following disclaimer shall be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Sucker Rod Pumping Web Site. The Artificial Lift Research and Development Council and its officers and trustees, and the Sucker Rod Pumping Workshop Steering Committee members, and their supporting organizations and companies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Sucker Rod Pumping Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained. The views, opinions, and conclusions expressed in these presentations and/or training materials are those of the author and not necessarily those of the Sponsoring Organizations. The author is solely responsible for the content of the materials. The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, non-infringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose.

Identify Problems Using Pump Plunger Motion IntroductionDynamometer Card Terminology Spring Constants�Kr & Kt Rods Elastically Stretch to Pick Up Fo from A-B & Un-stretch to Release Fo from C-DCompare Polished Rod Position to Pump Plunger Position - Anchored TubingCompare Polished Rod Velocity to �Pump Plunger Velocity (Anchored Tubing)Slide Number 8Compare Polished Rod to Pump Plunger Position (Un-anchored Tubing) Slide Number 10Plunger Stops Due to �Downhole Sticking Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20ConclusionsCopyrightDisclaimer