Reinjection Water Treatment in Oilfields: Background, Challenges, and Limitations of Traditional Technologies

Introduction to Reinjection Water

With increasingly stringent environmental regulations worldwide, total pollutant control and compliant water reinjection have become key objectives for oilfields. Under strict environmental requirements, water treatment systems must ensure stable and continuous compliance without leakage risks. Meanwhile, as oilfield production enters the middle and late stages, the water cut of produced fluids continues to rise, creating demand for more efficient, compact, and reliable treatment equipment.

However, existing produced water treatment systems often suffer from poor shock resistance, unstable performance, and difficult operation and maintenance, which restrict oilfield development.

As a result, reinjection water treatment has become a rigid and essential demand in the produced water treatment market. 

Traditional Reinjection Water Treatment Technologies and Their Limitations

Conventional reinjection water treatment processes have many drawbacks.

- Systems combining inclined plate settlers with walnut shell or fiber ball filters offer high permeability, but chemical dosing and aged oil reduce their reliability and shock resistance, resulting in unstable effluent quality.

- Processes based on settling tanks combined with radial dissolved air flotation, fiber ball or multimedia filters, and ceramic membranes are complex, energy-intensive, and costly to operate, with poor resistance to hydraulic and water-quality fluctuations.

- In addition, systems using settling tanks with radial flotation, fiber ball or multimedia filters, and ultrafiltration membranes are not resistant to high temperatures, have poor adaptability to crude oil, and show low long-term operational stability. High salinity further increases operation and maintenance difficulty and cost.