Production Optimization of ESP Wells Using the Proportional, Integral, and Derivative (PID) and Feedback Mode System in Sangasanga Field

Abstract

Sangasanga Field is one of main production contributor in PT Pertamina EP Asset 5 with production of 5525 BOPD or 31% to total production of Asset 5. Number of production wells in Sangasanga is 136 wells, which are 33 wells use ESP as artificial lift with total production 1763 BOPD or 32% to Sangasanga production Field. This shows that ESP performance in Sangasanga Field is an important aspect in achieving production target.

Some producing wells in Sangasanga Field have depleted pressure reservoir, so they have to be produced in low flowing pressure (less than 100 psi) to get oil rate according to their potentials. Based on the theory, ESP has intake pressure (Pi) limitation, usually the minimum intake pressure is 50 psi. If ESP runs in fixed frequency at depleted reservoir pressure wells, the Pi can reach below the minimum limit so the ESP will be off. In order to avoid ESP off due to low Pi alarm and to get continuous production, ESP has  to be set in Pi feedback mode. It means that the frequency will be adjusted automatically according to the Pi target. System that can be used in Pi feedback mode is Proportional, Integral, and Derivative (PID) and Feedback Mode System.

By using Pi feedback mode, the lifetime of ESP will be longer because it reduces frequency of trip due to low Pi alarm. There are 9 wells in Sangasanga Field that are set in Pi Feedback Mode, that totally produce 827 BOPD (equal to USD 20.6 million per year). By using Pi feedback mode, we can  continuously maintain 15% production of Sangasanga Field.