VICO Indonesia operates the Sanga Sanga PSC in East Kalimantan which is on production since 1972. Reservoirs are mostly gas and depleted. Very Low Pressure compression “VLP” systems, which operate at 15–25 psig suction, are widely installed across all fields. As a result, flowing tubing head pressures in a large number of wells are in the order of 40 psi. Completion tubing sizes range from 2 3/8” to 4.5” with the majority being 3.5”. Despite this, a large proportion of VICO’s existing gas wells are subject to liquid loading, leading to premature abandonment of producing zones when the gas velocity in the tubing is lower than the critical velocity. This phenomenon is influenced by the tubing size, surface pressure and the amount of associated liquids produced with the gas. Historically, some temporary activities were carried out to overcome this problem. This included the reactivation of wells by flowing to flare and/or dropping foaming agents. The result of this type of “temporary” application was very variable and inconsistent. In an effort to continuously optimize the system and reduce the abandonment pressures, a large scope deliquification project was launched in 2006. The project included the application of capillary strings for down-hole chemical injection, plunger lifts, and wellhead compressors. This program was applied across all fields in VICO. The results were very positive in bringing back the production strings previously considered marginal or not producing. The field wide implementation program for both capillary string units and well head compressors was conceived to allow periodic relocation and optimization of the units and the system. As a result, all these deliquification techniques have now become a core element of the Base Production System. They continue to be optimized on a day to day basis and as a whole they are responsible for approximately 10% of the total production from VICO.
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