【正文】 minimize unit cycling ? Soft starts the unit which reduces system mechanical and electrical stresses ? Protects the downhole equipment from under amp。 data logging capability ? Has auxiliary inputs for the various monitoring signals 197 The Variable Speed Controller Features amp。/or other wellbore factors, ., presence of H2S, high gas, etc. SPH, pp. 100102 190 Cable Temperature Temperature Ratings of ESP Cables insulation / covering / jacket (*denotes limiting material) ? Polypropylene* / Nitrile 205o F (96o C) ? Polypropylene* / Lead 220o F (105o C) ? EPDM / Nitrile* (with or w/o Barrier) 280o F (140o C) ? EPDM / Low Temp Barrier* / EPDM 300o F (150o C) ? EPDM / EPDM (with or w/o hi temp Barrier) 400o F (205o C) ? EPDM* / Lead Sheath 450o F (230o C) ? Motor Lead Extension Low Temp 250o F (120o C) ? Motor Lead Extension High Temp 400o F (205o C) ? Motor Lead Extension Lead Sheath 450o F (230o C) 191 Poly Cable KV Rating 3 KV 4 KV 5 KV 192 The Monitoring System ? Various downhole monitoring units can be attached to the bottom of the motor amp。 Benefits ? Available with any standard cable ? A variety of capillary tube sizes are utilized ? Available in round or flat profile ? Allows targeted delivery of treatment chemical ? Single or dual capillary designs ? Instrument wire can be inserted in some capillary tube sizes ? An outer layer of armor is applied to protect the capillary tubes Standard Power Cable Capillary Tubes Capillary Tube 189 Power Cable Application Proper application of ESP cable requires ... ? Limiting voltage drop to no more than 30 volts per 1000? and less than 15% of motor volts by choosing a sufficiently large conductor (AWG) size ? Choosing the proper profile based on tubing thread size vs. casing ID amp。 Braid or Lead Sheath (Low Temp or Hi Temp) 5 Armor (Low Profile Galv, SS, or Monel) ? Benefits: Tape and braid provides added depression resistance 1 2 3 5 4 186 Cable Types Extruded Barrier Components 1 Conductor (Copper) 2 Insulation (EPDM) 3 Extruded Fluorobarrier (Low or Hi Temp) 4 Jacket (Nitrile or EPDM) 5 Armor (Galvanized, Stainless, or Monel) ? Benefits: Unlike tapes, the barrier blocks fluid, aids depression resistance, and improves electrical properties 1 2 4 5 3 187 Cable Types Lead Sheath Components 1 Conductor (Copper) 2 Insulation (Polypropylene or EPDM) 3 Lead Sheath 4 Tape or Braid (on EPDM product only) 5 Armor (Galvanized, Stainless, or Monel) ? Benefits: Lead sheath blocks gasses amp。 Tape 4 Armor (Galvanized, Stainless, or Monel) ? Benefits: Less current imbalance amp。 jacketed copper conductors contained by metal armor ? Proper applications must address electrical, physical size, and operating temperature requirements 183 Cable Types Flat Components 1 Conductor (Copper) 2 Insulation (Polypropylene or EPDM) (Ethylene Propylene Diene Monomer) 3 Jacket (Nitrile or EPDM) amp。 current ? Is a two pole, three phase, AC, induction type ? Rotates at approximately 3500 RPM at 60 Hertz ? Is constructed of rotors and bearings stacked on the shaft and loaded in a wound stator ? Contains synthetic oil for lubrication ? Relies on fluid flow past the housing OD for cooling 170 Motor Components Stator Laminations KaptonWrapped Mag Wire Rotor Bearing with Tring Housing Epoxy Encapsulation 171 rotor Bearing with TRing Stator 172 Stator Laminations on a Mandrel 173 Stator Laminations pressed into the motor housing 174 A wound Stator with Leads attached 175 Rotor Copper End Ring Rotor Laminations Rotor Bearing Rotor T ring Rotor Spacers 176 Rotor Bearing Rotor 177 Motor Performance ? Motors are rated by horsepower, voltage, amp。 viscous drag forces add to upthrust. Hydraulic Thrust Pressure generated by the stage 72 Thrust and Impeller Position In normal operation the larger cross sectional area on the upper shroud causes more pressure on top, pushing the impeller down The pump is designed to operate in slight to moderate Downthrust. 73 Washers are fitted to prevent wear: Downthrust washers Upthrust washer Pump Thrust Load 74 Downthrust Washer 75 76 Upthrust Washer 77 Impeller Top Impeller Bottom 78 Hub Upper Shroud Vane Lower Shroud Skirt Eye Upthrust Washer Down thrust Washer Impeller Name the parts: 79 Shaft Thrust Shaft thrust is the result of the pump discharge pressure acting on the cross sectional end of the pump shaft The two things that determine shaft thrust is the pump discharge pressure (or TDH) and the diameter of the pump shaft. This thrust is transmitted directly to the seal section thrust bearing 80 Variable Speed Operation ESPs may also be ran at variable speeds. Changing the speed or frequency of an ESP system follows the “Affinity Laws” … ? New Flow Rate = Old Flow (New Hz/Old Hz) ? New Head = Old Head (New Hz/Old Hz)2 ? New Brake HP = Old BHP (New Hz/Old Hz)3 81 01020304050600 1000 2022 3000 4000 5000 6000Flow, Barrels per day (BPD) Operating Range Head Capacity Pump Efficiency Brake Horse Power Head in Feet BHP Pump Curve 80 60 40 20 1 2 3 Efficiency % Best Efficiency Point (BEP) 82 V a ri a bl e S pe e d O pe ra t i on0204060801001201400 500 1000 1500 2022 2500 3000 3500 4000 4500 5000Flow (BPD)Head (Feet)6 0 H zOperating Ra