Working principle of screw pump:

It is a positive displacement pump. It relies on the interference fit between the eccentrically moving rotor and the stationary stator to form a sealed cavity that is not connected to each other. Through the rotation of the rotor inside the stator, the sealed cavity extends axially from the inlet of the pump. The end moves to the outlet end, so that the medium in the sealed cavity can be transported by the pump.

Features of screw pump:

· Simple equipment structure

Small size, low transportation cost; simple ground installation, small footprint, convenient installation and maintenance.

· Suitable for heavy oil exploitation

Generally speaking, downhole screw pumps are suitable for the production of crude oil with a viscosity below 8000mPa.s, so most heavy oil wells can be applied.

· Adapt to high sand wells

Due to the good tolerance of the stator rubber, it can be used in oil wells with high sand content.

· Adapt to high gas content wells

The downhole screw pump will not have gas lock, so it is more suitable for oil and gas mixed transportation, but the free gas at the inlet of the downhole pump will affect the volumetric efficiency.

· Suitable for cluster well groups and horizontal wells in offshore oilfields

The downhole screw oil pump can be installed in the inclined vertical well section, and the equipment structure is simple, the area is small, the transportation and maintenance cost is low, so it is suitable for offshore oil extraction.