BASS STRAIT WATER HANDLING DEVELOPMENTS

Abstract

Esso Australia Ltd operates, on behalf of Esso/BHP, a crude oil and natural gas producing and processing facility in the Gippsland Basin, Victoria. Saline formation water produced with the oil is treated and discharged overboard from offshore platforms wherever possible to limit the volume of saline water in the pipeline system and avoid onshore disposal of saline water. Esso has developed oily water treatment and continuous oil-in- water monitoring beyond conventional technology and operates within stringent overboard water discharge regulations. Initial oily water treating installations were Cross Flow Interceptors, a corrugated plate gravity separator. Unsatisfactory performance prompted investigations leading to development of the Dissolved Gas Flotation unit using evolved gas to lift oil droplets to the surface. These units operate successfully offshore today. The most recent developments have been associated with a liquid-liquid hydrocyclone trade named 'Vortoil'. This has been tested offshore with an 'Purometer' continuous oil-in-water monitor. The Vortoil and Purometer have both performed favourably and proven a compact, low cost combination for future water treating installations.