Publications

The Arun Field has been producing since 1977 and, as of January 1, 2000, has produced over 90% of the total recoverable reserves. The average reservoir pressure is currently below 1000 psig, compared to the original pressure of 7,100 psig with an average reservoir temperature of 340o F. Because of the high reservoir temperature, a large amount of water is vaporized at reservoir conditions, which must then be removed at the surface.Upgrading the Arun Field dehydration facilities and booster compression will enhance gas deliverability. Currently, dehydration facilities are designed to operate down to a compressor suction pressure of 150 psig. At lower pressures, the dew point temperature of the gas in the facility and pipelines increases above 85o F. This condition has the potential for free water condensation that could lead to rapid corrosion in the gas pipeline to the LNG Plant.Upgrading of the existing facilities will allow operation down to 40 psig, while still meeting the dew point specification. Several processing alternatives were considered which included: glycol dehydration at the inter-stage of clusters, and recommissioning of the temporarily abandoned High Pressure (HP) propane refrigeration dehydration equipment. Use of corrosion inhibitors in the 42 pipeline was considered but eliminated due to reliability concerns.Re-commissioning of HP refrigeration equipment is the most economical option due to lowest cost and the fact that most of the equipment is already installed at site, and it builds on the process knowledge of the operations and maintenance personnel. Upgraded compressors will result in lower community noise and lower fuel consumption, since fewer machines will be required on line. Redundant machines can potentially be used in other areas.