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Well C, located in Field S, has been producing oil from the Baturaja Formation since March 2007. Well C was completed with a commingled zone and perforated at a 7-in casing liner, producing oil using an artificial lift electrical submersible pump (ESP) system. Well C has an average production of 260 barrels of oil per day (bopd) and an average bottomhole pressure (BHP) of 200 pounds per square inch (psi). Since 2013, the last three ESP installations have had a short run life of less than 100 days. These ESP installations experienced the same loss of flow problem.

The analysis based on sensor data during ESP operation, troubleshooting data, findings from the ESP pulling report, and the dismantle, inspection, and failure analysis (DIFA) report concluded that there are two possible causes for the frequent loss of flow in the ESP. The first possible cause is a significant amount of free gas entering the ESP pump, causing the ESP to be in a gas lock condition. These conditions cause the ESP head to derate and become unable to pump fluid production to the surface. The second possible cause is a wellbore geometry issue, specifically high dogleg severity (DLS) at the ESP setting depth, causing the ESP string to bend or the ESP shaft to break. When the ESP shaft bends or breaks, the ESP cannot deliver the optimal head to pump fluid production to the surface.

In December 2022, the ESP in Well C was pulled and reinstalled with a new technology artificial lift, the ultra-high speed (UHS) compact ESP. The UHS compact ESP technology can operate in a high and wide revolutions per minute (rpm) range of 6,000 to 10,000 rpm, compared to conventional ESPs that only have a maximum rpm of 3,600 rpm. Additionally, the UHS compact ESP is 75% shorter in length than conventional ESPs at the same fluid rate. After the UHS compact ESP installation in Well C, the running life of Well C improved significantly to 287 days. Although the UHS compact ESP experienced some loss of flow conditions with low tubing pressure at the surface, it was able to resume pumping fluid to the surface with higher tubing pressure. Meanwhile, the high DLS issue was mitigated with the shorter length of the UHS compact ESP.