Structural composition

The sucker rod pump system mainly consists of three parts:

1. Ground driven equipment

Including power sources such as pumping units, electric motors/diesel engines, as well as transmission components such as reducers and crank connecting rod mechanisms.

2. Underground pump body

Pump barrel: connected to the oil pipe and fixed underground;

Piston: Driven by the pumping rod, it moves back and forth in the pump barrel;

Valve system: suction valve and discharge valve, controlling the one-way flow of crude oil.

Special structure: The hydraulic feedback oil pump adopts a dual pump series design, which links the upper and lower plungers through the central pipe to improve the efficiency of heavy oil recovery.

3. Sucker rod column

Connected by multiple pumping rods, it transmits surface power to the downhole plunger and includes auxiliary components such as pump rods and pump caps.

Working principle

The sucker rod pump drives the plunger to reciprocate up and down through the ground pumping unit to lift crude oil, which is divided into two strokes:

1. Upstroke (plunger up)

The plunger is pulled up by the sucker rod, increasing the volume of the pump barrel and reducing the internal pressure;

The suction valve opens under pressure difference, and the formation crude oil enters the lower pump chamber;

The discharge valve is closed by the pressure of the oil column in the oil pipe, and the crude oil above the plunger is lifted to the ground.

2. Downstroke (plunger down)

The plunger descends and compresses the pump chamber, causing the pressure to rise above the pressure of the oil pipe column;

The suction valve is closed, the discharge valve is opened, and the crude oil in the pump chamber enters the oil pipe through the floating valve;

Shorten the sucker rod, extend the tubing, and complete a drainage cycle.

Key Features

1. Hydraulic feedback mechanism: The special pump type closes the suction valve and applies hydraulic pressure to force the plunger to overcome the resistance of heavy oil and move downwards, thereby improving production efficiency.

2. Load variation: During the upstroke, the sucker rod bears the weight of the rod column and the liquid column; During the downstroke, the liquid column pressure is transferred to the fixed valve, causing the rod column to shorten.

3. Motion conversion: The beam pumping unit converts rotational motion into reciprocating motion of the donkey head through the crank connecting rod beam mechanism, driving the pumping rod.

Application optimization

1. Pump barrel leakage control: Attention should be paid to factors such as clearance between plunger and pump barrel, axial force, etc., to reduce efficiency loss caused by leakage.

2. Suspension static load test: Due to the complex stress state underground, it is necessary to optimize the calculation model based on actual parameters to improve the accuracy of liquid column load.