(294b) Efficient Treatment of Produced Water - Investigations on the Use of New Ceramic Ultra- and Nanofiltration Membranes

The production of crude oil and natural gas is always associated with the co-production of water. This water is termed "produced-water". The quantity of water produced per unit volume of hydrocarbons varies greatly, but typically increases with the age of the producing field. As well as free and emulsified hydrocarbons, this water contain salts of many kinds, fine silts of both silicon and clay compositions and in some cases active biological materials. Produced water is always cleande to some extent. The existing technologies are not typically capable of reaching the new levels of cleanness demanded by regulations. To overcome these problems posed by the tighter regulations, operators have turned to membrane filtration schemes that have the potential to minimize additional costs and disposal issues. Both polymeric and ceramic membranes have been tried under many field conditions. While these membranes do a good job separating the oils, emulsions, and silts, they are prone to fouling by waxes and asphaltenes. The issues that need to be addressed are to prevent membrane fouling during operation and to provide an expedient, cost effective, and non-hazardous means of cleaning the membranes when they become fouled. The key technical obstacles for the integration of UF/NF membrane filtration for the oilfield water treatment process are reviewed. In addition results for average flux rates, flux degradation, backflushing and cleaning of new ceramic ultra- and nanofiltration membranes are shown.