• Choke it back or reduce operating Hz
电潜泵运行过程中所监测的参数
Gassy Conditions
•A
•B
•C
A. Current inrush on “across the line” startup
B. Decreased gas %, increased density, (increased amps) increased pressure, increased flow, increased inlet velocity and increased gas %
B. Curve should be smooth and symmetrical
C. Spike on startup is a normal occurrence on “across the line” starts
电潜泵运行过程中所监测的参数
电潜泵运行过程中所监测的参数
Pump Off
A. Starting Current Spike
电潜泵运行过程中所监测的参数
Gassy Conditions Causes and Solutions
Cause
• Low pump intake pressure allows gas in solution to become free gas
• Gas builds up on the low pressure side of the impeller vane, partially blocking the flow area
insulation system
电潜泵运行过程中所监测的参数
Pump Off Causes & Solutions
Cause
• Unit flow capacity is too large for the well
• Perforations are restricted
• Well inflow performance has changed
B. Normal Running Amps
C. Pump Off Begins D. Unit Hits
Underload Amps & Shuts Down
电潜泵运行过程中所监测的参数
电潜泵运行过程中所监测的参数
Pump Off Effects
• Production will be lower than anticipated
No Underload Shutdown
•A •B •C •D
A. Inrush current on “across the line” startup
B. Running at design point amps
C. Amps dropping due to fluid level drop in the well
电潜泵运行过程中所监测的参数
Motor Current
By monitoring motor current, an Operator can ...
• Look for trends in unit loading • Spot possible motor damage due to electrical or
• Key parameters must be monitored to insure proper operation of the system
• Failure to properly monitor or
interpret these parameters can be
costly
电潜泵运行过程中所监测的参数
Operating Parameters
Three basic ESP operating parameters are …
• Gross Production Rate • Pump Intake Pressure • Operating Motor Current
By monitoring these parameters, an Operator can better determine the relative condition of an ESP or anticipate possible problems
Cause
• Unit oversized for application
• Underload shutdown faulty or incorrectly set
• Running against a closed surface valve
Solution
• Reduce flow by increasing tubing back pressure, by lowering hertz or re-circulation
电潜泵运行过程中所监测的参数
Pump Intake Pressure
By monitoring PIP, an Operator can ...
• Determine relative unit sizing accuracy by comparing with the computer sizing
mechanical problems • Determine relative pump load or spot changes in loading • Detect changes in downhole fluid condition
Changes in operating current indicate that the motor is reacting to a new input from the pump, well, or electrical system. The Motor Controller should shut the unit off if the current varies beyond acceptable limits
with other unit data • Certain downhole conditions give unique
current signatures
电潜泵运行过程中所监测的参数
Normal Chart
A. May produce a curve that is below or above motor nameplate amperage
• Repair or re-adjust underload setting
C. Too much gas, low density, (decreased amps) decreased pressure, decreased flow, low inlet velocity,
电潜泵运行过程中所监测的参数
电潜泵运行过程中所监测的参数
Gassy Conditions Effects
电潜泵运行过程中所监测的参数
Flow Rate
电潜泵运行过程中所监测的参数
Production Rate
By monitoring the production rate an operator can …
• Determine the approximate operating point on the pump curve
• Possible seal section failure due to lack of lubricity and exceeding temperature of elastomers
电潜泵运行过程中所监测的参数
No Underload Shutdown Causes and Solutions
D. Running at near idle current with no shutdown
电潜泵运行过程中所监测的参数
电潜泵运行过程中所监测的参数
No Underload Shutdown Effects
• Motor will run hot due to no flow past the motor for cooling
• Unit was sized for future conditions
Solution
• Lower flow w/a surface choke or reduce operating Hz
• Chemical treatment
• Resize the unit, choke it back, or reduce operating Hz
– Lower fluid velocity past the motor – Higher than normal motor operating

• Excessive restarts of the unit
– Mechanical stresses to unit shafts – Electrical stresses to cable and motor
Solution
• Lower pump or decrease the flow
• Implement some form of gas handling technology
• Not a significant problem unless the pump gas locks
电潜泵运行过程中所监测的参数
• Anticipate unit cycling • Look for tubing leak, pump plugging and/or
wear
Increases or decreases in PIP can indicate a change in the pump performance, well inflow, or installation integrity