The submersible direct drive screw pump oil production outfit mainly includes: Permanent magnet submersible motor and its protector, thrust short connector, flexible shaft, screw pump, control cabinet and cable etc.

1. Permanent magnet synchronous submersible motor

It adopts the permanent magnet synchronous direct drive technology, and a flange connector or oil pipe thread connector is equipped at the bottom, for installing under-well detection devices, while a sensor connecting pigtail is installed additionally.

2. Motor protector – insulating well liquid and balancing internal and external pressure.

The configuration adopts a structure of double-capsule cavity and single sedimentation cavity; an independent and low-rotate speed thrust bearing bore is designed, to support the pump’s pushing force, protect the motor from pollution brought by well liquid, carry motor oil, and balance internal and external pressure of the system.

3. Thrust short connector – carrying axial load

It adopts a multi-level thrust bearing structure, which could bear axial force generated from the running of screw pump.

4. Flexible shaft – transmitting torque, and eccentric transformation

Flexible shaft adopts a universal structure, to realize transforming the concentric rotation of decelerator to an eccentric rotation, which is a flexible coupling device able to bear torque, or bear axial pressure.

5. Screw pump – lifting grease fluid

The screw pump molded lines adopt a short-amplitude cycloid design, while rubber could be selected according to well liquid, and its operation performance could meet system operation requirements.

6. Control system – parameter adjustment, operation protection and harmonic wave handling

It adopts a frequency conversion control system, operation speed of which could be adjusted manual or automatic according to requirements, with protection functions such as overload, under-voltage and short circuit etc., meanwhile, a filter is also equipped, which could handle harmonic wave, to guarantee effective operation of the system.

7. Cable – power transmission

Special under-well cable for oil well, could meet usage requirements of different under-well temperatures and mediums.

II. Connection of Parts

All parts are equipped with connection flanges and bolt holes, as shown in the figure.

The shown parts are connected via bolts accordingly. Oil pipe thread connection ports are fitted on screw pump, which are used to connect oil pipes.

Submersible cable plug ports are fitted on motor upper side, which are used to connect submersible cable.

III. Working Principle

The submersible direct drive screw pump system drives the under-well permanent magnet synchronous submersible motor’s rotation by a ground control system, via submersible cable, so as to realize the purpose of lifting crude oil.

IV. Movement Features

1. There’re no movable parts at wellhead, and a static seal mode is adopted, and the ground is safe and environmental-protective;

2. There’re no moving parts inside oil pipes, which completely solves the eccentric wear, and improves service life of oil pipes;

Service life;

3. Permanent magnet submersible motor is connected to screw pump, which is high in transmission efficiency, with an average power saving rate about 40%;

4. Under the conditions when the medium is water or crude oil, under different pressures, if the flow is even, and its adaptability to well liquid is sound, no “cavitation corrosion” or “airlock” would occur, and it could work with a relatively high efficiency in crude oil of high-viscosity;

5. It adapts to grease fluid lifting of various well types.

V. System Reliability

1. According to well situation information, system plan design could be carried out, and equipment customized mode could also be implemented;

2. System overall heat resistance could reach up to 120℃;

3. Protector adopts a double-capsule single sedimentation cavity structure, to effectively insulate well liquid and to balance internal and external pressure difference;

4. Cable adopts a special under-well armoured cable, and could carry out optimization configuration of internal materials according to well conditions;

5. The screw pump adopts rubber specially used by oil fields, as well as special processing technique, to effectively guarantee operation torque of the screw pump as well as volumetric efficiency.

VI. Technical Parameters

Permanent Magnet Synchronous Motor Technical Parameters

Motor Protector Technical Parameters

Screw Pump Technical Parameters

Note: The above is the list for only part of specification parameters, while processing could be customized according to requirements of customers.