Comprehensive Solution for Produced Water Treatment in Conventional Oilfield Blocks: SINOKLE's CDFU + KFM Technology

As the oil industry continues to develop in various countries, many oilfields have entered the middle and late stages of development, with decreasing oil production becoming a common phenomenon in the industry. To maintain oilfield production capacity and increase recovery rates, water injection development has become an important means of enhancing oilfield output. However, the quality of produced water directly affects the effectiveness of water reinjection development, oilfield production efficiency, and places higher demands on environmental protection.

In conventional oilfield blocks, produced water for injection mainly comes from treated oilfield wastewater that meets discharge standards. The characteristics of this produced water include high oil content, abundant suspended solids, and serious bacterial growth. If the quality of the produced water does not meet standards, it can lead to formation clogging, increased injection pressure, reduced recovery rates, and in severe cases, even cause oil wells to shut down. Therefore, choosing an economical and efficient produced water treatment technology is crucial.

Analysis of Treatment Challenges

The treatment of produced water in conventional oilfield blocks faces three major technical challenges:

1. High Difficulty in Oil-contaminated Water Treatment: Oilfield wastewater contains various forms of oil such as dissolved oil, emulsified oil, and dispersed oil. Among them, emulsified oil forms a stable thermodynamic equilibrium system with water, with oil droplet sizes ranging from 1 to 50 microns. Traditional gravity separation and filtration technologies are unable to effectively remove this emulsified oil.

2. Excessive Suspended Solids: The oil extraction process introduces large amounts of suspended solids, including sand, corrosion products, and bacterial metabolites. These fine suspended solids easily clog formation pores and reduce injection permeability.

3. Bacterial Growth Leading to Corrosion: Wastewater contains microorganisms such as sulfate-reducing bacteria and iron bacteria. These bacteria produce acidic substances during metabolism, accelerating the corrosion of injection equipment and pipelines, thus shortening their lifespan.

Limitations of Traditional Technologies

Currently, the commonly used produced water treatment processes in oilfields are the "oil separation - flotation - filtration" combination process, but they have significant drawbacks:

· Oil Separation Pools: Oil separation efficiency for emulsified oil is low, and they can only remove most of the free oil, but not the finer emulsified oil.

· Traditional Flotation Systems: The gas bubbles generated by traditional flotation equipment are relatively large (50-100 microns), reducing the probability of contact with fine oil droplets, which limits the oil removal efficiency.

· Quartz Sand Filters: The filtration precision of quartz sand filters is generally low, and their ability to retain suspended solids is limited. Additionally, they tend to cake easily, resulting in poor backwashing performance.

Moreover, traditional processes occupy large areas, consume large amounts of chemicals, and have high operating and maintenance costs, which makes it difficult to meet the oilfield's cost-reduction and efficiency-increasing demands.

SINOKLE's Comprehensive Solution

Shenzhen Clear Science & Technology Co., Ltd (SINOKLE) has launched a comprehensive solution to address the challenges of treating produced water in conventional oilfield blocks. The solution is centered around the CDFU Cyclonic Dissolved-gas Flotation and KFM Activated Filter-media filter.

The CDFU Cyclonic Dissolved-gas Flotation unit is a core product independently developed by SINOKLE. This device combines centrifugal separation technology with dissolved-gas flotation, utilizing CFD-optimized flow field designs to generate ultra-fine bubbles with diameters of only 5-30 microns. These microbubbles fully interact with the emulsified oil droplets, causing them to adhere and form floating sludge with a density lower than water, thus easily separating oil from water. Compared to traditional flotation equipment, CDFU improves oil removal efficiency by more than 50%, with the oil content in the effluent being stably controlled at below 5 mg/L.

The KFM Activated Filter-media filter uses high-quality quartz sand filter media, with the surface specially treated to improve its ability to adsorb and retain oils and suspended solids. The KFM filter has a high filtration precision, effectively removing fine suspended solids, with the suspended solids in the effluent being reduced to below 1 mg/L. Additionally, the filter material is thoroughly backwashed, does not cake, and has a service life of 5-8 years.

Advantages of the Technology

SINOKLE's produced water treatment solution for oilfields reinjection offers significant advantages:

· Excellent Treatment Efficiency: The CDFU+KFM combined process consistently delivers effluent that meets discharge standards, with oil content below 5 mg/L and suspended solids below 1 mg/L, fully meeting the oilfield produced water quality standards (SY/T 5329-2012).

· Small Footprint: The equipment uses skid-mounted design. A CDFU unit with a treatment capacity of 200 m³/h requires only 15 square meters of space, saving more than 60% of the land area compared to traditional processes.

· Low Operational Costs: The process uses pure physical methods, without the need for chemical additives, avoiding secondary pollution and significantly reducing operating and maintenance costs. The equipment is highly automated and can operate unattended.

· Wide Application Range: The solution is well-suited for a wide range of oilfield water injection treatments, including heavy oil fields, conventional blocks, and low-permeability oilfields.

Conclusion

The treatment of produced water in conventional oilfield blocks is a critical component in ensuring the sustainable development of oilfields. SINOKLE's CDFU+KFM combined process offers a reliable technological option for produced water treatment, with its high efficiency, energy savings, and stability. The solution has been successfully applied in multiple oilfields, accumulating extensive engineering experience and providing significant economic and environmental benefits for oilfield companies.