【正文】 ertical 169 The Motor ? Drives the downhole pump and seal section ? Is rated for a specific horsepower, voltage, amp。 current ? At a constant voltage, by varying the pump load or brake horsepower applied to the motor, current will change ? At a constant load, by varying voltage, current will vary, as well 178 Motor Application Motor operating temperature is determined by 5 factors ? Wellbore Temperature ? % Load vs. Nameplate Rating ? Fluid Velocity Past Motor (flow rate vs. unit/casing diameter) ? Cooling Properties of the Well Fluid (% gas, water cut, scaling tendencies, etc.) ? Power Quality (3 phase voltage/current imbalance, wave form distortion, full nameplate voltage available, etc.) All of the above factors determine if, and when, a motor will overheat during operation 179 SPH p49 180 Motor and VSD ???????6060HZNP H PNP H P HZ???????6060HZNP VNP V HZ60N P AN P A HZ ?181 Motor and VSD sizing the motor ???????6060HZNP H PNP H P HZ???????HZB H PNP H P HZ6060Substitute the pump BHPHZ at the maximum design HZ for the NPHPHZ and solve for NPHP60 182 The Power Cable ? Is made up of the power cable and motor lead ? Can be made in round or flat profile ? Is constructed of three insulated amp。 Tape 4 Armor (Galvanized, Stainless, or Monel) ? Benefits: Low profile to fit in tight clearance installations 2 4 3 1 184 Cable Types Round Components 1 Conductor (Copper) 2 Insulation Polypropylene or EPDM (Ethylene Propylene Diene Monomer) 3 Jacket (Nitrile or EPDM) amp。 runs cooler than equivalent flat cable 3 2 4 1 185 Cable Types Motor Lead Extension Components 1 Conductor (Copper) 2 Insulation Film (Polyimide) 3 Insulation (EPDM) 4 Jacket / Tape amp。 protects conductor from H2S attack ? Available in round profile with EPDM jacket 2 5 4 3 1 188 Cable Types Capillary Tube Features amp。 conductor size ? Selecting a cable type based on operating conductor temperature amp。/or deployed separately in the wellbore ? Signals are either impressed (DC) on the power cable or sent via separate instrument wire ? Available monitoring options include … – Pump Intake Pressure – Pump Intake Temperature – Motor Operating Temperature – Discharge Flow Rate – Discharge Pressure – Discharge Temperature – Unit Vibration 193 The Surface Equipment The surface equipment (beyond the wellhead) consists of … ? The Motor Controller ? The Transformer(s) ? The Junction or “Vent” Box ? Wellhead ? Surface Cable 194 The Controller System The two types of controllers used with ESP systems are … ? Switchboards (fixed speed) ? Variable Speed Controllers (aka “drives”) Both types of Controllers can be made to read monitoring system output signals Both types generally require transformers to convert the supply or output voltage to the required unit voltage 195 The Switchboard Features ? Applies full voltage and current to the downhole system on start up (aka “across the line” starting) ? Utilizes a motor controller unit for system protection and monitoring ? Is hooked to transformers which convert the ining voltage and current to the required voltage and current for the ESP system Disadvantages ? Starting across the line results in extremely high mechanical and electrical stresses on the system ? Does not allow pumpwell mismatch or fine tuning which results in unit cycling ? Flow control can only be acplished with a surface choke which may result in the pump operating outside of its remended range 196 The Motor Controller The motor controller … ? Is the “brains” of the switchboard ? Monitors ining voltage and current to the downhole system ? Can be set up to allow automatic restart under certain conditions ? Protects the motor from voltage and current fluctuations and imbalance ? Some models have RTU munication amp。 Benefits ? Allows fine tuning of unit performance to the well which can increase efficiency amp。 over current as well as voltage unbalance and transients ? Delays pull and resize of equipment to restore production rate due to wear 198 Variable Speed Pump Curve Head vs. Flow, Variable Speed (3090 Hz), Single Stage, Sg = 200 Graphic display Interface The VSC Graphic Control System 201 GCS Main Menu The anization of parameters and information is mon for the 9 main menu options on all GCS products. 202 GCS Status Screen 203 The Transformer The transformer … ? Converts supply voltage and current to a level at or near the required system voltage and current ? Has multiple tap settings for flexibility ? Must be of a special design to work properly with VSCs ? Should be sized to be greater than or equal to the required total KVA of the downhole system 204 The Junction Box The Junction Box … ? Provides the main contact point between the downhole unit cable and the surface equipment cable ? Provides a point of separation to determine downhole or surface electrical faults ? “Vents” gasses that escape through the cable insulation and jacket in certain low pressure wellhead designs A typical ESP installation 206 Objective ? Upon letion of this course, you should be able to: Explain the uses for Electrical Submersible Pumps. List the major ponents of an ESP system. Explain the principle of an ESP system.