EVN5 Submersible screw twin pumps and field units on their base are designed to pump stratal liquid of higher viscosity out of the oil wells having a nominal diameter of casing string of 146 mm as per GOST 632-80. Minimum internal diameter – 121,7 mm.
The content of mechanical admixtures in the liquid being pumped out – is not to exceed 0,8 gr/l, the content of free gas at pump intake by volume – not more than 50%, water content – not more than 99%.
Maximum temperature of liquid under formation conditions – 343 К (70°С) for the pumps furnished with shells made of rubber 2D-405.Maximum viscosity of liquid under formation conditions - 1*10-3 m²/s.
The field unit consists of pump , electric motor completed with hydroprotection , lines of the current lead with a cable joint box , control station , and transformer.
The pump comprises: two pairs of working members (shell with screws) with the right and left-handed direction of the spiral, two eccentric clutches, the base with foots (pivots) made of siliconized graphite, overrunning clutch, safety valve and stationary base members.
In the top portion of the pump there is a safety valve. Provision is made in pumps of modification K for the special attachment which is installed between the protector and the electric motor. The said attachment eliminates any ingress of clay mortar into the zone of master clutch.
The submersible pump unit is lowered into a well by way of the oil well tubing. Furthermore, the cable is fastened to the said tubing by special belts. The startup of the electric motor is carried out through the complex device. In unit operation, the torque through a shaft of the protector, then, master clutch, power shaft and eccentric clutches of the pump is transmitted to the working screws.
The liquid via the filters is sucked in simultaneously by upper and lower screw pairs.
Two pairs of working members (shell-screw) are working in parallel and are creating a pressure which is required to lift the liquid to the surface.
The flow from a pump is equal to the sum of feedings of two working pairs, and the head of the pump is equal to the head of each working pair.
|Pump models||Flow (nomin.), m³/day||Flow (rang), m³/day||Rotation speed, c˜¹||Pump outlet pressure, MPa, max||Pump outlet pressure (rang), MPa, max||Pump efficiency,%||Engine power, kW|
Example 2 EVN 5 12 1000 V5 TU 3665-024-05747979-99, where :