Commissioning and Start up procedure for ESP

Commissioning and Start up procedure for ESP

Before Starting the ESP you must take theses Safety  precautions :

1- General electricity handling :

• Ensure that the equipment is installed in a secure and upright position in a properly ventilated location.
• Making sure equipment is clean, dust free, and dry from the inside as this can cause electrical failure.
• All plugs and cables that interface to any printed circuit boards, shall be checked at both ends as those connectors can become loose during shipping.
• All high current connections are to be checked for tightness as loose connections can develop arcing which in turn can cause damage to both the surface unit and the equipment that the surface unit is operating.
• The wiring shall be checked before energizing the equipment to ensure that the surface unit is wired correctly for the application.
• Do not work on energized electrical parts without adequate illumination.
• Do not work on energized electrical parts if there is an obstruction that prevents seeing your work area.
• Do not work on energized electrical parts if you must reach blindly into areas which may contain energized parts.
• Bare live parts shall be guarded against accidental contact by means of approved cabinets or other forms of approved enclosures except where the bare live parts are located in an enclosed area, which is accessible only to qualified persons.
• Never use a megger on the rig floor to check insulation integrity.
• Always discharge each winding internally into the megger after test, NEVER spark discharge the motor windings.
• Always stand to one side of the controller for system start up.
• Only approved PPE should be worn when working on the equipment. Its never a good practice to wear: metal hard hats, jewelry (rings, watches, necklaces, etc.), wire rim glasses (unless insulated or covered with proper safety glasses), large metal belt buckles, or clothing containing conductive material. Typically the Nomex coveralls should be worn when working on this type of equipment. These coveralls provide a margin of safety against electrical shock as well as arc burns.

2- Grounding Of Electrical Equipment :

• The act of providing a pre-determined safe path for stray electrical current
• A properly installed ground offers a low resistance path for electricity to flow to the ground system helping to prevent dangerous shocks.
• System grounding protects electrical components within the circuit from damage by excess voltage or line surges.
• The best earthing point (most commonly used) for all electrical surface equipment on a well site is the well casing.

3- Lock Out and Tag Out (LOTO) :

• Lock Out / Tag Out is the procedure that notifies and limits access to unauthorized personnel to the equipment. This is typically done with the gang locks and tags shown to the right. When all work is done the locks can be removed by the qualified personnel to allow the equipment to then be operated
• OSHA reports approximately 120 deaths and 10% of all serious industrial accidents annually are caused by unexpected start-up or release of stored energy

4- Electrical Surface Equipment Hazards :

• All field personnel must not power the switchboard until the entire operation manual is reviewed and understood
• Install the switchboard in a secure and upright position; a minimum distance of 50 feet from the well with a junction box in between is mandatory
• Once the switchboard is installed at the site it is necessary to check all wiring connections, a ‘tug and pull’ test will help locate any loose connections as well as all pre commissioning checks listed in the specific operations manual and Artificial Lift Field Service Manual
• Whenever replacing a blown fuse always install the same type and rated fuse that was originally supplied
• Course-trained personnel should be accompanied and mentored by experienced personnel until deemed competent to work unsupervised. At this point they will be considered qualified personnel and should be able to service the equipment without issue
• Qualified personnel should have their reference material on hand for troubleshooting and repair issues
• Field personnel must not work on energized switchboard unless necessary
• All field personnel must be fully aware of each component of the switchboard and its function and able to locate the high & low voltage parts of the panel
• With power applied to the switchboard, qualified field personnel should verify the incoming voltage at the main disconnect using the proper meter & PPE
• All switchboards must be grounded properly to reduce the risk of electrical shock and to reduce electrical noise
• Appropriate PPE must be used when verifying the 120 VAC control voltage on the PT secondary since a live  high voltage is present on  the near primary side
• With the switchboard switched off (vacuum contactor is open) and the main disconnect switch disengaged there is still hi-voltage present at the three phase input of the disconnect switch
• Field personnel must not rely on the current status of the stopped (tripped) switchboard since there is a good chance of auto restarting (if not locked out or manually switched off)
• Before commencing any troubleshooting / maintenance to the switchboard field personnel must switch off, lock out and tag out incoming power prior to working on equipment
• Verify with an appropriate voltage measuring device that all circuits do not have voltage applied to them . Failure to do so may result in severe injury or death to personnel and major damage to or destruction of equipment

ESP Power requirements :

1- Surface Voltage :
Which can be calculated using the rated voltage and amperage of the motor nameplate, the length and size of the power cable, by using the following equations and cable voltage drop chart :

2- Operating Current :

Calculate what the operating current might be based on the horsepower requirement of the pump at the initial operating frequency which could be determined by using the following equation :

3- Surface KVA :

From the required surface voltage, calculate Surface KVA. For installations that include a step-up transformer, the surface KVA can be determined from the following equation :

Example:

Determine the required surface voltage. Assume a motor rated at 890 V and 58A and 120 HP with 3600 ft of No. 4 AWG copper cable in a well and pump 90 HP Find the (Surface voltage), (operating current), (Required KVA).

Surface voltage :

      surface voltage required = motor nameplate voltage + cable voltage drop/1000 ft

      surface voltage required = 890 V + 104 V

      surface voltage required = 994 V

Operating current :

operating current = (pump HP) (nameplate current) / (motor HP).

operating current = (90) (58) /  (120)= 43.5A.

operating current = 43.5A

Surface KVA :

Surface KVA = (Required Surface Volts * Amps * 1.73) / 1000 

Surface KVA = (994* 58 * 1.73) / 1000

Surface KVA = 99.7

Transformer :

1- Transformer power specification check :

The transformer nameplate as shown below should be checked carefully, the KVA rating must be greater then the surface KVA, also voltage and current are compatible with surface voltage and operating current.

2-Setting the transformer taps :

Transformer should be properly tapped to provide the correct voltage which should be +/-10% of required Surface voltage, as the following example will show.

Example :

How should the transformer be adjusted to obtain a secondary voltage of 2450 Volts when the primary voltage is 480 Volts?

The secondary winding is connected "Wye", Switch No 1 should be set at position 2, and for the correct voltage switch No 2 should be set at position 4.

3- Commissioning Transformers :

• All bolted connections to be checked and tightened as per the Manufacturing of the transformer
• Tank and fittings should be inspected for damage or leaks
• Leaking bushings should be tightened prior to applying power to the transformer
• Tap settings should be recorded and measured voltages should be recorded
• Resistance measurements should be taken on both primary and Secondary windings Results should be recorded
• Windings should be tested with 1000 volts DC megger. Primary and secondary phases may all be joined together for measurement, readings should be recorded
• Remove backspin shunt if used. Readings are to be taken from Primary to Ground, Secondary to Ground, and Primary to Secondary
• Oil sample should be taken at customer’s request only
• Operating temperatures should be recorded during loaded operation
• All safety devices/shields should be replaced and secured

Junction box :

The junction box is used for connecting the power cable and venting gas (in case gas has migrated up the power cable) between the well and switchboard.

It should be in line with the switchboard if possible, and at a distance of approximately 15-25 feet from the well and should be wired as the figures.

Switchboard :

1- Components :

As the figure shown below all switch board components should be visual checked for physical damages from transportation and correctly adjusted.

2- Location Considerations :

Install the switchboard in an upright and secure position, and bolt it to a stable base, in a minimum of 50 feet from the well. Also avoid installation in areas of extreme vibration or heat, or near sources of electrical noise.

3- Cable Entry and power Wiring :

It is recommended that power and control cables enter at the bottom or on the left side of the enclosure as the figure shows input and output terminals on the switchboard.

4- Switchboard Commissioning :

• Once the switchboard is installed at the site it is necessary to check all wiring connections, including the grounding connection between the switchboard and earth ground. A ‘tug and pull’ test will help locate any loose connections.
• The PT settings must be verified against the drawing located on the inside door of the high-voltage compartment of the switchboard for the available PT taps.
• Ensure that the main disconnect, breaker CB-1, and breaker CB-2 are all OPEN.
• With the disconnect switch closed, the voltages on the PT secondary should be verified to be within the controller input range (0-120 volts AC).
• The CT burden module rating must be consistent with the motor Current rating in the , The ampere rating of the switchboard must not exceed the range of the CT burden module, and if only CT is used correct CT ratio should be determined using the equation; CT size = expected amps through switchboard X 1.6

Example :

Assume 59 A will pass through the switchboard.

59 A x 1.6 = 94 A

Choose a CT with the primary winding rating closest to 94 A. In this case a100:5 CT is appropriate. This ratio will keep the recording amp-meter pen in the middle of the chart during normal operating conditions.

• Verify the phase wiring is correct: Phase A (RED) on the left, Phase B(BLACK) in the center, and Phase C (BLUE) on the right. It is Important to ensure that the phase wiring is correct at the main disconnect, vacuum contactor, transformer primary inputs, transformer secondary inputs, wellhead junction box, and motor lead connections.
• With power applied to the switchboard, a qualified electrician should verify the incoming voltage at the main disconnect.
• Test all fuses and check for correct current handling.

Surface choke installation :

The surface choke should be installed and wired as shown below :

Start up procedure :

1- Motor start up :

• Perform a complete visual check of the cabinet
• Remove all wire insulation stripping, pieces of conductor, and debris from the bottom of the cabinet (ensure the cabinet is clear of all debris)
• Ensure all bolt torque requirements have been met
• Install all necessary shields and covers
• Conduct an electrical insulation resistance test to verify the switchboard wiring integrity. A 5 kV megohmmeter (megger) is recommended for this test
• Close the cabinet door and tighten the door handle.
• Ensure that all steps in the Switchboard/UniConn are done correctly with no problems.
• Verify that no alarms are active and/or latched and the unit is not locked out. If any of these conditions are active, unlock the unit, unlatch the active latched alarm(s) and clear all other active alarms by rectifying their cause(s).
• Install a pressure gauge on the wellhead and a choke (for controlling flow) in the flowline.
• Notify the wellsite personnel production department that the system is about to be started.
• Ensure all valves are in their correct operating position.
• Clear all personnel from the area and start the pump.
• Select HAND/AUTO operation mode, then press START. If the unit is locked out or any alarm is still latched, the START button will not appear in the display when HAND/AUTO mode is selected.
• The OVERLOAD and STALL alarms may temporarily display during startup, These alarms should clear within the alarm time delay and will not shut down the drive under normal circumstances
• Note the three-phase current measurements with an ammeter and adjust the UniConn readings if required.
• Observe the Start Amps value. If the STALL alarm is used, its set point must be set below the Start Amps value.
• Closely monitor the current to ensure the motor is not overloaded, and record the starting current and current readings every five minutes.

2- Pump rotation :

• Partially close the flow choke, until the tubing pressure is 200 to 300 psi (13.8 to 20.7 bar) greater than the open-choke operating pressure.
• Without adjusting the choke, shut down the motor and reverse the rotation by switching any two leads in the junction box. Observe electrical safety procedures before switching leads.
• Start the motor again and observe the tubing pressure at the wellhead. If the pressure exceeds the previously recorded pressure, then the pump is rotating in the correct direction. If the pressure does not exceed the previously observed pressure, the present rotation is backwards.

3- Final installation checks :

• Switchboard and junction box properly grounded.
• Recording ammeter drive wound and fitted with the correct chart.
• Ammeter pen is marking properly.
• Overload and underload properly calibrated.
• All alarms and trips are properly adjusted.
• Ensure that no-load and load voltages have been observed and noted on run report.
• Run report complete with all information.
• Name tags have been tied together and stored in a safe place inside the switchboard.
• Shipping caps properly assembled and stored under or close to switchboard. record the exact location of the caps on the run report.
• Purchase order number and field signatures obtained as required.
• No tools or instruments left on location.
• Legible copy of run report left in switchboard.
• Ensure all access covers and doors are closed on the switchboard, transformer and junction box.
• All trash disposed of properly.
• All work has been performed in a neat, professional manner.