Sucker Rod Pumping Short Course (PDF) v1.1 by Downhole Diagnostic 

Oilfield Rod Pumping Optimization and Gas Interference
Oilfield Downhole Pump Performance

Download the full 6-page brochure and feel free to share with any and all.

 As a gift to the industry, I compiled this 6-page brochure outlining (in as concise a fasion as possible) the Principles of Sucker Rod PumpingDesign, Operation, & Optimization. I labored many weeks in putting it together, so I hope it will be of value to you in your operations.  I had several well known industry leaders proof-read it for accuracy and I have only had to make one slight modification to the material since first publishing (thanks to helpful feedback from Dr. Sam Gibbs).  Cheers and happy pumping!
Image of a PRT (Polished Rod Transducer) clamped onto a Polished Rod (used to acquire Dynamometer data)
Oilfield Fluid Level Gun used to determine the depth to the liquid level on rod pumped wells.
Echometer's Horseshoe Dynamometer used for determining the downhole pump performance on beam lifted wells.
Image showing Echometer's PRT & Horseshoe Dynos installed on a Rod Pumping Well in Pecos, Texas.
Fluid Level Shots & Dynamometer Cards
 
Perfect 100% Fillage

Perfect 100% Fillage

Dynamometer Cards: perfect 100% pump fillage with anchored tubing (rectangular pump card).

Unanchored Tubing

Unanchored Tubing

Dynamometer Cards: 100% liquid fillage with unanchored tubing. Pump card slants up-right at the Rod Spring Constant.

Fluid Pound Cards

Fluid Pound Cards

Dynamometer Cards: well is fully pumped off to the SN and pounding fluid 45% fillage.

Gas Interference

Gas Interference

Dynamometer Cards: this well has a long-stroke pumping unit with bad gas interference with the stereotypical gas compression down-stroke.

Gas Interference w/ Gas Expansion

Gas Interference w/ Gas Expansion

Dynamometer Cards: gas interference/compression seen on the down-stroke and lots of gas expansion seen at the start of the up-stroke (which usually indicates a poor compression ratio in the pump; check the pump spacing).

Pump Tag - Overtravel

Pump Tag - Overtravel

Dynamometer Cards: pump has a solid down-stroke tag and the Pump Card shows lots of over-travel (downhole stroke length is much longer than the surface stroke length at the pumping unit).

Tagging - Tag vs No Tag

Tagging - Tag vs No Tag

Dynamometer Cards: the blue cards show the well tagging hard (lots of noise generated in the cards from the tag). I raised the rods to remove the tag and then cards smoothed out (black cards).

Pump Tag - 10K

Pump Tag - 10K

Dynamometer Cards: Pump had a very solid tag: 10,000-lbs of compression! This is how you smash the top clutch of the pump (shown in image).

Pump Tag - Slow Stack Out

Pump Tag - Slow Stack Out

Dynamometer Cards: pump has a solid tag but this unit is running at a slow SPM with a short stroke length and so the tag did not seem to hard at surface, but it is damaging and unnecessary. The rods stack out on the pump 8" before the bottom of the down-stroke. Considering how short the SL is, this 8" tag is consuming about a 1/3rd of the downhole stroke length!! Raising the rods will increase production by increasing the stroke at the pump.

Upstroke Pump Tag

Upstroke Pump Tag

Dynamometer Cards: the plunger is pulling into the top of the pump (trying to unseat it) at the top of the up-stroke. You know the pump is spaced far off bottom when you see this: need to drop the rods.

Pump Tag - Based on Fillage

Pump Tag - Based on Fillage

Dynamometer Cards: the pump is spaced very close to bottom and it does not tag when it has 100% fillage but it does tag when the fillage drops (due to the changing dynamics of the stress waves in the rod string); well has Fiberglass rods.

Worn Pump

Worn Pump

Dynamometer Cards: pump is worn but still has some life left.

Worn Pump - Worn Out

Worn Pump - Worn Out

Dynamometer Cards: the downhole rod pump is completely worn out and is close to picking up the full fluid load in the middle of the stroke but it never does. The well was not producing anything in this condition: need to change the pump.

Hole in Pump Barrel

Hole in Pump Barrel

Dynamometer Cards: the pump has a hole in the bottom third of the pump barrel and once the bottom of the plunger moves past the hole the pressure across the plunger is equalized and the fluid load on the plunger drops to zero. The image shows the pump barrel in the tubing and shows how this pressure equalization works.

Delayed Traveling Valve Closure

Delayed Traveling Valve Closure

Dynamometer Cards: the cards show normal 100% fillage cards versus two strokes with the pick-up in the fluid load is delayed. The Delayed Traveling Valve Closure is due to either trash getting between the ball and seat of the Traveling Valve or some damage damage on the surface of the Traveling Valve. (it can also be due to Bottom Discharge Valves not immediately seating if your pump has those installed).

Plunger Stuck in Pump Barrel

Plunger Stuck in Pump Barrel

Dynamometer Cards: pump plunger is stuck in the barrel and the whole up-stroke is nothing but rod tension.

Rods Sticking in Paraffin

Rods Sticking in Paraffin

Dynamometer Cards: the rods are sticking/balled up in paraffin and the plunger is still moving some but most of the stroke is lost due to rod stretch from the paraffin binding to the rods. The downhole pump is not computed correctly as the Wave Equation things the tension from the paraffin is actually some force acting downhole at the pump (...it does not know it is acting higher up the hole due to the paraffin friction).

Solids Grinding Between Plunger & Barrel

Solids Grinding Between Plunger & Barrel

Dynamometer Cards: Solids getting caught between the plunger and barrel and partially sticking the plunger for a second (tension is pulled which frees the plunger).

Friction Card

Friction Card

Dynamometer Cards: This is an example of some higher dog-leg (severe deviation in the wellbore) which is causing a lot of rod-on-tubing friction at that point. The pump is set at 10,000' on this well and the dog-leg is around 3500'. The Wave Equation does not know there is a localized point of excessive friction higher up the hole and thinks everything is happening at the pump, so the pump card is not properly computed (which causes the characteristic down-right slant of the Pump Card).

Leaking Standing Valve

Leaking Standing Valve

Dynamometer Cards: The Standing Valve is partially leaking and the full fluid load is only released off the plunger in the middle of the down-stroke when the plunger is moving the fastest.

Hydraulic Horsepower Card

Hydraulic Horsepower Card

Dynamometer Cards: This is an example of a shallow well with an over-sized tubing pump (2.75" in a 2-7/8" tubing). The pump is bottled-up and you see a hump at the start of the up-stroke due to the increased acceleration/friction forces from pushing so much fluid through the restricted ID of the tubing.

Stuffing Box Friction

Stuffing Box Friction

Dynamometer Cards: This is an example of excessive stuffing box friction distorting the card. The stuffing box friction is seen as the pumping unit changes directions and is highlighted by the brackets.

Slippage vs Gas Locked

Slippage vs Gas Locked

Dynamometer Cards: Example cards from the same well when it had 100% liquid fillage (with some slippage) versus when the pump gas locked. Look at the difference in area between the cards (which represent the amount of work being performed).

Combo - Rod Stretch + Tag

Combo - Rod Stretch + Tag

Dynamometer Cards: The well shows lots of rod stretch (due to a high fluid load from the 2" pump and a lot of stretchy fibgerglass rods) and it has a solid pump tag. Think you could feel the tag at surface??? The tag is arriving to surface 35" into the up-stroke, so it is not the easiest tag for the pumper to identify if they don't have some dynamometer cards to look at.

Changing SPM

Changing SPM

Dynamometer Cards: This well had a VSD (Variable Speed Drive) and the unit is increasing SPM from 4.5 to 8.2 during the cards shown. Notice how the downhole stroke length increases as the pump gets some over-travel due to the elasticity of the fiberglass rods being jerked around.

Can Opener Card

Can Opener Card

Dynamometer Cards: This is what is termed as a "Can-Opener" card and it is a combination of incomplete pump fillage (either due to gas interference or fluid pound) and wear/slippage.

Gas Pound - Fillage Slowly Dropping

Gas Pound - Fillage Slowly Dropping

Dynamometer Cards: The pump fillage is slowly working down each stroke in this data set. The cards tend to indicate fluid pound based on there shape but the Fluid Level Shot indicates there is 300' of Gas Free Liquid Above the Pump (GFLAP), so this is what I term "Gas Pound".

Traveling Valve Ball Damaged

Traveling Valve Ball Damaged

Dynamometer Cards: The cards on this well change from good 100% fillage cards to cards that show heavy wear. How can a pump change back and forth from being worn to not being worn? Answer: pitting or misshaped Traveling Valve ball. Depending how the ball lands from stroke-to-stroke affects how effectively the plunger/valve create a pressure seal on the up-stroke.

Tension at Polished Rod Box

Tension at Polished Rod Box

Dynamometer Cards: You might jump to the conclusion these cards show an up-stroke tag at the pump but notice how the tension at the pump is slanted up-right. In this well, the Polished Rod was not spaced properly and the coupling/box on the bottom of the PR was being pulled up into the stuffing box creating the tension. The software doesn't know that and assumes the tension is occurring at the pump.

Go to the Oilfield Pictures tab to find more helpful images in the gallery pictures.
Helpful References for Sucker Rod Pumping:  (Green=Link)
 

Books:

 

Websites:

  • Echometer - they have some great rod-pumping software & insightful industry papers that can be freely downloaded. 

  • Penta Completions - has some good downloads at the bottom of the page ("Product Catalog" the most expansive).

  • Don-Nan Pump & Supply - good pictures and spec sheets on TAC's, rod pumps, & pump components.

  • Artificial Lift Research & Development Council (ALRDC) - some reference artificial lift pictures and links to some software packages (but website not well maintained).  The best info is located under the central "Services - Open" tab.

 

Rod Pumping Videos & Animations

 

PDF's & Additional Reference Information:

  • Rod Failure Analysis by Norris:  great 22-page failure analysis brochure detailing the different mechanisms causing sucker rods to fail and showing detailed images that are very helpful for identifying sucker rod root-cause failure analysis.
  • Rod Specs by Penta Completions:  helpful reference table listing all the rod dimensions (from wrench flat to end fitting diameter, etc).  Reference is helpful when determining what size overshot to run to fish out any type of rod part.
  • Motor Frame Size:  use to determine the shaft diameter for the motor sheave (when changing the SPM).   

 

Rod Pumping InSight:  (Click through images)
 

© 2020 by Dowhole Diagnostic  |  Midland, TX

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Leaking Standing Valve

Dynamometer Cards: The Standing Valve is partially leaking and the full fluid load is only released off the plunger in the middle of the down-stroke when the plunger is moving the fastest.