Produced Water Reinjection Treatment Technology and Its Development

Produced water treatment has long been a major challenge in oilfield operations. With stricter environmental requirements and rising water volumes in the mid-to-late life of fields, conventional processes struggle to meet stable compliance. SINOKLE has developed a series of innovative solutions to this problem.

Technical core: CDFU Cyclonic dissolved-air flotation unit

SINOKLE's core CDFU (cyclonic dissolved-air flotation) unit combines centrifugal separation, dissolved-air flotation and microbubble generation into an efficient oil-water separation system. Its bubbles are only 5-30 microns in diameter, greatly improving separation efficiency.

Compared with conventional technology, CDFU offers clear advantages: residence time falls from 15-40 minutes to under 5 minutes, oil removal rises from 60%-85% to over 90%, and suspended solids removal exceeds 80%. Enclosed operation and automatic control ensure safety and stability.

Complete process solutions

SINOKLE offers three graduated options according to water quality requirements and formation permeability:

Fig. Produced water reinjection treatment process

· Option 1 (high-permeability formations): after the three-phase separator, produced fluid passes through two stages of CDFU and KFM active filter media, giving effluent oil ≤10mg/L and suspended solids ≤5mg/L

· Option 2 (low-permeability formations): adds a second-stage KFM filter to Option 1, giving effluent oil ≤6mg/L and suspended solids ≤2mg/L

· Option 3 (ultra-low-permeability formations): based on Option 1, add a modified inorganic membrane filter, giving effluent oil ≤5mg/L and suspended solids ≤1mg/L

Technical advantages

Strong shock resistance is a hallmark of SINOKLE's technology. The equipment adapts to changes in hydraulic load, oil viscosity and oil density and performs well on high-concentration polymer-containing produced water, cutting influent oil of ≤2000mg/L to ≤10mg/L in the effluent.

The environmental benefit comes from purely physical demulsification: no chemicals are added, so oily sludge is eliminated at the source and secondary pollution is avoided. The process is short and compact, and the skid-mounted design suits space-constrained sites such as offshore platforms.

Field application case

At a Congo oilfield produced water project in Africa, SINOKLE's technology performed outstandingly. Influent oil was as high as 3825mg/L with 972mg/L suspended solids; after two stages of CDFU treatment, oil fell to 27.5mg/L, and after KFM filtration the final effluent contained only 4.1mg/L oil and 4.6mg/L suspended solids. The project handles 200m³/h on a footprint of only 400 square metres.

Intelligent operation

SINOKLE's equipment integrates IoT technology for fully automatic intelligent operation. The system monitors water quality in real time, adjusts operating conditions automatically and supports remote control and unattended operation. This intelligence cuts labour costs and ensures stable, reliable treatment.

Development prospects

As environmental standards rise, SINOKLE keeps innovating. The company now holds more than 30 patents and has built deep experience in oilfield produced water treatment. Its solutions address today's technical difficulties and provide reliable support for sustainable oilfield development.

SINOKLE's produced water solutions, with innovative technology and stable performance, are setting a new benchmark for oilfield environmental management worldwide and providing complete, economic, efficient and environmentally sound technical support for oilfield production.