電潛泵運(yùn)行過程中所監(jiān)測的參數(shù)

1、ESP Operating Parameters,ESP Operation,Once an ESP system is commissioned, the operator plays a key role in the system’s performance and run lifeKey parameters must be monitored to insure proper operation of the system

2、Failure to properly monitor or interpret these parameters can be costly,Operating Parameters,Three basic ESP operating parameters are …Gross Production RatePump Intake PressureOperating Motor CurrentBy monitoring th

3、ese parameters, an Operator can better determine the relative condition of an ESP or anticipate possible problems,Flow Rate,Production Rate,By monitoring the production rate an operator can …Determine the approximate op

4、erating point on the pump curveTrend the rate of declining productionLook for possible pump wear, tubing leaks, etc.Loss of production is usually the first indicator of a downhole problem with an ESP,Pump Intake Press

5、ure,By monitoring PIP, an Operator can ... Determine relative unit sizing accuracy by comparing with the computer sizingAnticipate unit cyclingLook for tubing leak, pump plugging and/or wearIncreases or decreases in

6、PIP can indicate a change in the pump performance, well inflow, or installation integrity,Motor Current,By monitoring motor current, an Operator can ... Look for trends in unit loadingSpot possible motor damage due to

7、electrical or mechanical problemsDetermine relative pump load or spot changes in loadingDetect changes in downhole fluid conditionChanges in operating current indicate that the motor is reacting to a new input from th

8、e pump, well, or electrical system. The Motor Controller should shut the unit off if the current varies beyond acceptable limits,Amp Charts,Amp charts are a valuable troubleshooting toolAmp charts record the motor curr

9、ent over timeTrends in motor loading can be analyzed along with other unit dataCertain downhole conditions give unique current signatures,Normal Chart,A.May produce a curve that is below or above motor nameplate amper

10、ageB.Curve should be smooth and symmetricalC.Spike on startup is a normal occurrence on “across the line” starts,Pump Off,A. Starting Current SpikeB. Normal Running AmpsC. Pump Off BeginsD. Unit Hits Underload Amp

11、s & Shuts Down,Pump Off Effects,Production will be lower than anticipated Lower fluid velocity past the motorHigher than normal motor operating temperatureExcessive restarts of the unitMechanical stresses to unit

12、 shaftsElectrical stresses to cable and motor insulation system,Pump Off Causes & Solutions,CauseUnit flow capacity is too large for the wellPerforations are restrictedWell inflow performance has changedUnit was

13、 sized for future conditions,SolutionLower flow w/a surface choke or reduce operating HzChemical treatmentResize the unit, choke it back, or reduce operating HzChoke it back or reduce operating Hz,Gassy Conditions,A.

14、Current inrush on “across the line” startupB.Decreased gas %, increased density, (increased amps) increased pressure, increased flow, increased inlet velocity and increased gas %C.Too much gas, low density, (decreas

15、ed amps) decreased pressure, decreased flow, low inlet velocity, decreased gas %,A,,B,,C,,Gassy Conditions Effects,Stock tank barrels may be lower than anticipatedVolume seen by the pump would be higher than stock tank

16、barrels due to gas breakout after leaving the pump dischargeAmperage fluctuations are caused by entrained and free gas in the fluid productionUnit operates continuously without gas locking, therefore, not considered to

17、 be a significant problem,Gassy Conditions Causes and Solutions,CauseLow pump intake pressure allows gas in solution to become free gasGas builds up on the low pressure side of the impeller vane, partially blocking the

18、 flow area,SolutionLower pump or decrease the flowImplement some form of gas handling technologyNot a significant problem unless the pump gas locks,No Underload Shutdown,A.Inrush current on “across the line” startup

19、B.Running at design point ampsC.Amps dropping due to fluid level drop in the wellD.Running at near idle current with no shutdown,A,,B,,C,,D,,No Underload Shutdown Effects,Motor will run hot due to no flow past the m

20、otor for coolingPossible motor lead extension cable failure due to pump running hotExtended operation in this mode will result in motor failure due to overheatingPossible seal section failure due to lack of lubricity

21、and exceeding temperature of elastomers,No Underload Shutdown Causes and Solutions,CauseUnit oversized for applicationUnderload shutdown faulty or incorrectly setRunning against a closed surface valve,SolutionReduce

22、 flow by increasing tubing back pressure, by lowering hertz or re-circulationRepair or re-adjust underload settingVerify surface valves are open and chokes properly adjusted,A.Inrush current on “across the line” start

23、upB.Unit pulling design point ampsC.Unit shuts down due to external signalD.Times out and re-starts,External Shutdown,A,,B,,C,,D,,External Shutdown Effects,Could result in excessive cyclingLimiting cyclic operatio

24、ns should prolong run lifePossible startup during backspin if auto restart timer is not adjusted to allow time for backspinPotential for twisted or broken shafts if started during backspin,External Shutdown Causes

25、and Solutions,CauseTypically a programmed functionTank level switches, high-low pressures switches, timersUnit cycled to control total production,SolutionLimit cyclic operationAllow sufficient time for backspin, ins

26、tall backspin relayIncrease tubing pressure, decrease hertz,Pumping Debris,A.Inrush current on “across the line” startupB.Erratic amperage due to pumping debrisC.Pumping clean fluid and amperage has stabilized,A,,B

27、,,C,,Pumping Debris Effects,Pump could become plugged with debrisdecrease in productionreduced cooling for the motorPump could become locked upMay require pulling from the wellOverload trip could occuroverloading o

28、f motor and cable system,Pumping Debris Causes and Solutions,CauseWell was not properly cleaned prior to installing the ESPKill fluids in the wellImproper startup procedures in sandy wells,SolutionThe well should be

29、 cleaned prior to installing an ESP and @ each workoverKill fluids should be of minimum SG to maintain well controlProper startup procedures should be implemented,Additional Operating Parameters,Other operating paramet