Three large-scale projects that use membrane technology developed for the reuse of produced water for injection purposes or Enhanced Oil Recovery (EOR) processes have been successfully commissioned in Chinese oil fields.
Produced water treatment systems that incorporate X-Flow membrane technology followed by either reverse osmosis (RO) or ion exchange are producing low-salinity reinjection water for EOR.
At the Daqing Oil Field, the largest in the People's Republic of China and one of the most productive oil fields in the world, a full scale two-stage ultrafiltration (UF) plant pre-treats 5,000 m³/d of produced water to make it suitable for reinjection.
At the same time, valuable chemicals are recovered. This oil field requires a large amount of injection water, about 25,000 m³/day. The limited water resources in the area make it necessary for the produced water to be reused.
The same membrane technology is applied at the Yanan Fengfuchuan and Yanan Wangpiwan oil fields, where 1,500 m³/d and 1,200 m³/d respectively are treated.