sucker rod pump

1. Introduction

A Sucker Rod Pump (SRP), also known as a beam pump or nodding donkey, is the most widely used artificial lift method in the oil industry. It mechanically lifts fluid from a well when natural reservoir pressure is insufficient for production.

2. Main Components

A sucker rod pump system consists of surface and downhole components:

Surface Equipment:

• Pumping Unit (Prime Mover) – Converts rotary motion into reciprocating motion (e.g., beam-balanced or long-stroke units).

• Polished Rod – Connects the surface unit to the sucker rod string.

• Stuffing Box – Seals the wellhead to prevent leaks.

Downhole Equipment:

• Sucker Rod String – Transmits motion from the surface to the downhole pump.

• Pump Barrel – A cylindrical chamber where the plunger moves.

• Plunger – Creates pressure differentials to lift fluid.

• Traveling & Standing Valves – Check valves that control fluid entry and discharge.

• Anchor/Tubing – Secures the pump assembly in place.

3. Working Principle

1. Upstroke:

   • The pumping unit lifts the sucker rods, pulling the plunger upward.

   • The traveling valve closes, and the standing valve opens, allowing fluid into the barrel.

2. Downstroke:

   • The rods push the plunger downward.

   • The standing valve closes, and the traveling valve opens, forcing fluid up the tubing.

This reciprocating action creates continuous fluid lift.

4. Types of Sucker Rod Pumps