At present, rod pumping pump (referred to as "sucker pump") still occupies a dominant position in all modes of oil production. It is estimated that there are more than 150000 rod pumping wells in China's petroleum industry and hundreds of thousands of rod pumping wells in the world. Most of the domestic oilfields have entered the middle and late stage of development, facing the influence of oil layer sand production, high water cut, polymer injection development, heavy oil thermal recovery and strong corrosion of medium environment and poor well conditions, resulting in the wear and tear, leakage and corrosion of the oil pump. The failure of sand card, scaling, deformation and so on makes the free period of oil well pump shorter and shorter, which seriously affects the improvement of comprehensive economic benefit of oil field development.

The latest changes in the application condition of the pump and the adaptability of the pump products to these changes are directly related to the progress of the whole oil production. Horizontal well technology has become an effective means to exploit the potential of remaining oil at the top of thick reservoirs in old areas and to exploit thin differential layers in peripheral oilfields. The three-plunger mechanical valve-type inclined well pumping pump has become the main fluid extraction tool in horizontal well, directional well and high deviated well area in the field of horizontal well, directional well and high deviated well.

In view of the above operating conditions and failure analysis, our company has developed a three-plunger mechanical valve-type inclined well oil pump which is suitable for sand production, high gas-liquid ratio, pump hanging depth and high slope.

The pump combines the structural characteristics of inclined well pump and valve pump, improves the design principle of common pump, breaks through the traditional plunger structure of pump, adopts mutually independent multi-stage sealing unit structure plunger, and each stage is independent of each other. The plunger seal unit is in a free state between the center rod and the rod string, and the eccentric force of the rod string acts on the centralizer and is subjected to the eccentric wear by the centralizer when used in the production of high deviated wells and horizontal wells, and the force of eccentric force of the rod string acts on the centralizer. It can effectively eliminate the partial wear of the sealing unit of the downhole pump. To improve the material of every component of the pump and to use the advanced manufacturing technology, the whole pump can be improved in applicable working condition and service life. 

Structural composition:

The three-plunger mechanical valve type inclined shaft oil-well pump adopts a three-stage sealing unit structure plunger which is completely independent from each other, and is independent of each other, even if one or two stages of the plunger fail and can be produced normally. Mainly comprises an upper joint, a pump barrel, a plunger assembly, a pin oil drain, a fixed valve assembly and a lower joint.

Working principle:

During the upper stroke, the plunger goes up, the fixed valve is opened, the swimming valve is closed, the lower cavity is pumped into the pump, and the upper cavity is drained out of the well; when the down stroke, the plunger goes down, the swimming valve is opened, the fixed valve is closed, the lower cavity liquid enters the upper chamber.

Technical parameters:

Technical characteristics: 

1. The piston assembly of the pump adopts the integral three-stage seal structure, which is independent of each other, strong open-close, fast-opening and closing, and has anti-gas function, thus improving the pump efficiency.

Ø2. The single-stage sealing unit is sealed by a non-contact elastic gap, and the structure can reduce the sealing gap, reduce the leakage amount and improve the pumping effect.

3. By changing the hard clearance between the plunger and the pump barrel into an elastic clearance, the pump jam is avoided, the piston running resistance is reduced, and the damage caused by sand particles to the pump barrel and the outer surface of the plunger can be avoided, and the inspection period of the pump is prolonged.

4. The eccentric wear of the sealing unit of downhole pump can be effectively eliminated by the eccentric wear of the centralizing mechanism.

5. The fixed valve cover is equipped with guide bars. Under the action of spring and push rod, the valve ball is forced to close to avoid the problem of large deviation well section valve ball closing hysteresis, sealing is not strict.

6. Matching pin spillers, when checking the pump, the rod can be used to discharge the pipe string, avoid the injection of pipe string, and ensure clean production.

U applicable well conditions:

1. It is suitable for high deviation well and horizontal well with 0 / 85 °deviation of pump position.

2. Suitable for sand wells. The pump has strong sand carrying capacity and can ensure normal production under the condition of no sand embedded plunger (pump).

3. Suitable for pump deep well.

4. It is suitable for conventional oil wells, sand producing wells, high deviation wells, horizontal wells, high gas cut wells, dilute wells, heavy oil wells, steam throughput wells, steam drive wells, deep wells and so on.