What does a normal dynamometer card look like?

A normal surface card is roughly rectangular: relatively steady peak load on the upstroke and lower load on the downstroke, with distinct corners. Large rounding, mid-stroke spikes, or collapsed load separation usually indicate a problem.

What is fluid pound on a dynamometer card?

Fluid pound appears as a sudden load change when the plunger strikes liquid after traveling through gas or incomplete fillage. It stresses rods and the pumping unit and usually means the well is pumped off or gassy.

Can SCADA replace pulling a dynamometer card?

SCADA/POC systems that upload surface cards reduce how often a truck must collect a card, but interpretation and setpoint changes still need a competent analyst. Downhole cards require additional sensors or models.

Dynamometer Card Interpretation Guide for Rod Pump Wells

Quick Answer

A surface dynamometer card is a plot of polished-rod load versus position over one pump stroke. Healthy cards look roughly rectangular. Distorted shapes point to incomplete fillage, gas interference, fluid pound, stuffing-box friction, or valve leakage. Pump-off controllers (POCs) and SCADA systems that upload cards let one analyst cover dozens of wells — if the crew can read the shapes.

Original schematic cards (NFM educational diagrams)

These SVGs are original teaching diagrams, not scans of proprietary vendor cards.

Normal card: relatively flat top and bottom loads, clear upstroke/downstroke corners.

Gas interference: delayed load pickup and rounded or “soft” corners as gas compresses in the barrel.

Fluid pound: abrupt load change when the plunger hits liquid after a gas/void interval — hard on rods and gearbox.

Valve leakage: reduced separation between upstroke and downstroke loads; confirm with fluid level and runtime trends.

How to use cards with POC / SCADA

Trend fillage % and peak/min load daily — cards for exceptions.
Compare to a known-good baseline after a pull or POC setpoint change.
Do not “fix” fluid pound by ignoring SPM limits — change stroke or setpoints with a plan.
Store cards with well ID, SPM, and timestamp for the next workover conversation.

NFM integrates POC dyno uploads into SCADA so pumpers see problem cards before the polished rod fails.

Frequently Asked Questions