Three water-reuse projects for oilfields in China that use Pentair X-Flow ultrafiltration (UF) membrane technology have been commissioned recently.
Produced-water treatment systems that incorporate X- Flow membrane technology, followed by either reverse osmosis or ion exchange, offer the opportunity to produce low-salinity reinjection water for enhanced oil recovery. This lower salinity water can have a positive effect on the overall oil production volumes.
At the Daqing Oil Field, the largest in China and one of the most productive oilfields in the world, a full-scale two-stage UF plant pretreats 5,000 m³/d of produced water to make it suitable for reinjection. At the same time, valuable chemicals are recovered.
This oilfield requires about 25,000 m³/d of injection water. 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 oilfields, where 1,500 m³/d and 1,200 m³/d respectively are treated.