Oil Pumpjack

Overview

An oil pumpjack, a beam pumping unit, is the familiar nodding lift on land wells that lack the natural pressure to flow to surface. A surface engine drives a pivoting beam up and down, and the beam reciprocates a string of rods running thousands of feet to a subsurface plunger pump that lifts crude with each upstroke. It is the most common form of artificial lift because it is rugged, mechanically simple, and easy to service.

The unit converts continuous motor rotation into a slow reciprocating stroke, with counterweights storing energy on the down-stroke to even out the load the motor sees.

How it works

The Prime Mover (Electric Motor) drives through the V-Belt Drive into the Gear Reducer (Double-Reduction), a double-reduction gearbox that drops motor speed to a few strokes per minute while multiplying torque. The slow output shaft turns the Pitman, Crank & Counterweights assembly, whose cranks and counterweights drive the pitman arms.

Those arms rock the Walking Beam & Horsehead about its center bearing on the Samson Post (A-Frame) A-frame. The beam's horsehead and bridle keep the polished rod pulling vertically through the stroke. At the surface the Wellhead Interface carries the polished rod through a stuffing box and routes produced fluid out the pumping tee.

Below ground the Downhole Equipment string of sucker rods reciprocates an insert pump: on the upstroke the traveling valve closes and the standing valve opens to draw fluid into the barrel; on the downstroke the valves reverse and lift the column. A Crankshaft Brake parks the crank for service, and the Control Panel pump-off controller and VFD slow or idle the unit when the well draws down to prevent pumping the reservoir dry.