INTRODUCTION:

As oil reservoir produces its fluid, formation pressure declines in proportion to produced fluids. There is situation where formation pressure cannot overcome total weight of fluids inside tubing, where the well stops flowing. In order to continue producing fluids, additional energy must be introduced into production tubing in order to (a) reduce overall fluid weight, or (b) increase wellbore pressure to overcome fluid weight. The first option can be done by injecting gas into production tubing, known as gas lift method.

The second option can be done by (1) using mechanical means to lift the fluid, known as sucker rod pump,

(2) injecting hydraulic fluid or compatible liquid into production tubing, knows as hydraulic pump,

or (3) increase wellbore pressure by installing pump at the very end of production tubing, known as electric submersible pump (ESP).

ESP provides high fluid rate compare to sucker rod and hydraulic pump and comparable with gas lift method for high productivity wells. Nevertheless, fluid flow from reservoir to wellbore is not always constant and can be varied due to natural causes. Fluid flow rate variations yields to uneven loading of production tubing and for ESP wells can cause pump damage.

In order to minimize pump damage, a method is required to be able to change pump capacity by changing rotation speed and motor torque based on well condition. Variable Speed Drive (VSD) or also called an inverter is a motor speed regulator by changing the value of the frequency and voltage entering the motor. Setting the value of frequency and voltage is intended to get the rotation speed and torque of the motor that is desired or according to needs.

In the VSD, the inverter gets an AC current (Alternating Current) that comes from source power on the well platform. To be able to set the AC current voltage must be changed to DC Current (Direct Current) through a step down transformer, the DC current received by the VSD can be adjusted according to the needs of the ESP motor. After the voltage has been set by the VSD the DC current can be received by the motor into an AC current through the Step up Transformer then the current will be received to drive the ESP motor.

The function of the VSD in the operation of the Electric Subsumersible Pump (ESP) work:

- System for controlling motor rotation speed by controlling the frequency of electric

  power supplied to the ESP pump motor.

- Save operational electricity by adjusting the voltage according to the needs of the

  ESP pump motor.

- Using VSD can maintain the voltage of electric current received by the motor,

  thereby reducing mechanical and electrical stress, reducing maintenance and

  repair costs, and extending ESP motor life.

SPECIFICATION:

Our Variable Speed Drive (VSD) is Schneider Altivar 61 and is currently available 3 (Three) Types:

- 260 Kva (4 unit)

- 390 Kva (3 unit)

- 450 Kva (3 unit)

SUCCESS STORY:

We provide VSD for CNOOC Ses Ltd. running at South East Sumatera Block with all area business unit (Central Business Unit (CBU), North (NBU) and South (SBU),  5 years without NPT and can increase pump lifetime because it is supported by a program that can be adjusted to well conditions .

Continue running business with Pertamina Hulu Energi Offshore South East Sumatera (PHE OSES) in all area business unit (CBU, NBU and SBU).