Sucker Rod Pumping Short Course (PDF) v1.1 by Downhole Diagnostic
3/31/2022 - Interview I did on the Tech in Operations podcast. Video link and podcast link below. 1.5-hr
Detailed Descriptions how Fluid Level Guns and Dynamometers Work: (click image to link to page)
Fluid Level Shots & Dynamometer Cards
Perfect 100% Fillage
Dynamometer Cards: perfect 100% pump fillage with anchored tubing (rectangular pump card).
Dynamometer Cards: 100% liquid fillage with unanchored tubing. Pump card slants up-right at the Rod Spring Constant.
Fluid Pound Cards
Dynamometer Cards: well is fully pumped off to the SN and pounding fluid 45% fillage.
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
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
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
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
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
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
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
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.
Dynamometer Cards: pump is worn but still has some life left.
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
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
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
Dynamometer Cards: pump plunger is stuck in the barrel and the whole up-stroke is nothing but rod tension.
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
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).
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
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
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
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
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
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.
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
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
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
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
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.
1 Fluid Level Shot & Tubing Collars
Fluid Level Shot & Tubing Collars (from wireless Echometer equipment with TAM software).
2 High Fluid Level w/ Repeat Reflections
High fluid level with repeat reflections (amplitude of reflections reduces as energy is lost): pressure wave is bouncing between the top of the fluid level and the wellhead.
3 Fluid Level Below Perfs
Fluid level shot where the well is pumped off (fluid level at the Seating Nipple) and the microphone picks up kicks from the TAC and perfs. Not easy to see the top of the fluid level due to the perfs 'swallowing' so much of pressure wave.
4 FL Below TAC
The TAC (Tubing Anchor Catcher) can be clearly seen in this shot above the top of the fluid level.
5 Liner Top & Repeat
Three kicks show up and the top of the production liner if very clearly shown. The reflection off the liner top is exactly 2x the distance to the top of the liner.
6 Suspected Csg Leak
I found a large up-kick high up the hole on this well (where there was not supposed to be any perfs or other annular discrepancies), and since the well was still producing to surface it can't be a tubing leak, so it looks like this well has a casing leak (maybe a dry casing leak, or a previously leak that was squeezed off with cement).
Go to the Oilfield Pictures tab to find more helpful images in the gallery pictures.
Helpful References for Sucker Rod Pumping: (Green=Link)
The Beam Lift Handbook: by Dr. A.L. Podio & Dr. Paul Bommer (2012) - a comprehensive ref. with fantastic diagrams.
Rod Pumping: Modern Methods of Design, Diagnosis, and Surveillance: by Dr. Sam Gibbs (2012). (This book is more for the engineer and those who want to understand the underlying equations)
Rod Pumping Optimization: by John Svinos at Theta Oilfield Services (2014 Edition, e-book).
Accoustic Fluid Level Measurements: by Dr. Podio & James McCoy (2017).
Southwestern Petroleum Short Course (SWPSC): $300 for a CD containing electronic copies of every paper ever presented at SWPSC going back to 1954. The papers come with an Adobe Acrobat Catalog Index—making keyword searching for specific topics very easy—and the papers are primary focused on production/completion related activities pertaining in the Permian Basin. This is where I cut my teeth early on in my self-education on rod pumping.
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
Visualizations of Downhole Pump in Relation to Dynamometer Pump Card Shapes (4 min) - by Petrobras. This shows great animations that intuitively help in understanding Pump Card Shapes (the few words that are written in the video are in Spanish, but the visualizations are in English). This video is well worth the time.
Sucker Rod Pumping System (2 min) - by Weatherford. Animation of pumping unit stroking the downhole pump.
Clear Plexiglas Rod Pump Showing Incomplete Fluid Fillage (45 sec) - University of Texas laboratory test well.
3 Causes of Incomplete Pump Fillage (7 min) - by Lynn Rowland from Echometer at the SWPSC (2010).
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)
These slides are from my training courses I have done.
These slides are from my training courses I have done.