Kaji Semoga (KS) field has produced primarily from limestone and has until recently contained sufficient gas for gas lift usage. However, KS gas production is declining rapidly: it is estimated that by 2013 it will produce insufficient gas. As a result, some new forms of artificial lift are being considered to replace gas lift, and since the end of 2008 new ESP and HPU projects have been carried out with the aim of such a new form of lift. As a result of implementing these projects, ESP wells will be the dominant artificial lift for production wells in KS, contributing to approximately 70% of total oil production

On the other hand, there are risks of downtime associated with the use of ESP. The main risks concern downhole problems, which need rig deployment, and electrical problems, which cause the ESPs to shut down. Fixng these problems may require a considerable amount of time - several days or even weeks - due to reasons such as unavailability of a rig and/or spare parts. This will inevitably result in loss of oil .production.

To avoid such production loss, an ESP / gas lift hybrid system has been implemented, whereby gas lift is prepared as a backup. This hybrid system consists of an ESP unit installed along with a gas lift system in single tubing, with no packer and 1 (one) (screen orifice) gas lift valve, 1 (one) sliding sleeve door, and 1(one) complete ESP unit.

All ESP wells in KS (currently 70 wells and counting) now use this configuration. The gas lift hybrid system has been used as backup during ESP downtime. This configuration can produce 35% of liquid compared to normal ESP liquid production, and as a result an oil loss of 4400 bbls was prevented during 2009.

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