Breakthroughs and Practice in Hydraulic Fracturing Flowback Fluid Treatment
1. Overview
In oil and gas exploitation, especially during hydraulic fracturing operations, a specific fluid known as fracturing flowback fluid is produced. Hydraulic fracturing is a stimulation measure that injects high-pressure fluid into the reservoir to create fractures, thereby improving oil and gas permeability and recovery. The process consumes large volumes of fracturing fluid, which is typically a mixture of water, proppant and various chemical additives. Because of its complex composition and the possible presence of environmentally hazardous substances, it can easily pollute water bodies and soil. As environmental regulations become stricter and public environmental awareness grows, the safe disposal of fracturing flowback fluid is increasingly critical.
Fig. Fracturing operation
At present, the main disposal routes for fracturing flowback fluid are: formation reinjection — pumping fluid that has been treated to standard back underground as injection water for oil recovery; recycling — reusing suitably treated flowback fluid to prepare new fracturing fluid systems; and advanced purification — for fluid that is not suitable for direct reinjection or reuse, advanced treatment to meet environmental discharge requirements, usually involving the removal of organics, heavy metals, suspended solids and other pollutants. However, the flowback fluid is complex and variable in composition, posing challenges for treatment processes, such as risks of secondary pollution and high treatment costs. Continuously developing new treatment technologies and methods to improve treatment efficiency and results therefore remains an important direction for the industry.
2. SINOKLE's Core Treatment Technologies Based on CDOF and CDFU
SINOKLE has assembled an R&D team of domain experts and experienced engineers that keeps track of global technology trends and continuously overcomes technical difficulties, laying a solid foundation for the continuous improvement and iteration of the CDOF and CDFU technologies. As the company's key innovation in fracturing flowback fluid treatment, the CDOF + CDFU process integrates both high-efficiency separation and advanced purification, offering a breakthrough solution to this environmental challenge. CDOF technology relies on its unique continuous dynamic oil–water separation principle, employing advanced micro/nano filtration media combined with crossflow filtration to achieve highly efficient separation of the oil, water and solid phases in the flowback fluid, with separation efficiency exceeding 98% — far superior to conventional methods. This technology not only greatly increases treatment speed but also markedly reduces the load and cost of downstream treatment. Compared with traditional processes, CDOF can cut energy consumption by about 30%, thanks to its optimized hydrodynamic design and highly efficient ozone catalytic media, which reduce equipment flow resistance and energy losses, bringing considerable economic benefits to the petrochemical sector.
Fig. Process flow of SINOKLE's CDOF + CDFU fracturing flowback fluid treatment
CDFU technology represents a further deepening and extension of CDOF. It integrates deep filtration modules with a high-efficiency recovery system, providing finer filtration and purification of the water after initial CDOF treatment and ensuring that the effluent meets strict national and industry standards. According to SINOKLE's actual project data, water treated by CDFU reaches suspended solids below 5 mg/L and a COD removal efficiency above 80%, with a treatment time only 1/3 to 1/5 of that of conventional methods. Working in synergy, CDOF and CDFU remove suspended solids, oils, heavy metals and other pollutants from the flowback fluid through the combined actions of high-efficiency separation and deep filtration, bringing the treated water into compliance with national discharge requirements — or even allowing direct reuse in production — thus greatly reducing potential environmental risks.
3. Project Implementation Results
A representative example is the successful application of SINOKLE's CDOF + CDFU fracturing flowback fluid treatment process at a large oil and gas field in Xinjiang, China. The project faced the challenge of treating flowback fluid with high salinity, high suspended solids and complex chemical composition. Leveraging the highly efficient separation mechanism of CDOF and multi-phase ozone catalytic oxidation, the SINOKLE team achieved effective separation of solid particles from the liquid phase: effluent suspended solids were below 10 mg/L, separation efficiency reached 98%, and single-stage COD removal exceeded 80% — far above the industry average. This significantly reduced the difficulty of downstream treatment while also cutting energy consumption and carbon emissions during treatment, fully reflecting the design philosophy of environmental protection and energy saving.
Fig. SINOKLE CDOF + CDFU fracturing flowback fluid treatment site
Through its fine filtration process, CDFU further upgraded the water after CDOF treatment to a standard suitable for direct reuse: the raw water contained more than 2000 mg/L of oil, while the effluent oil content was below 20 mg/L, with a water quality compliance rate of 99.5%. Meanwhile, the high-efficiency recovery system effectively recovered useful components of the flowback fluid, such as some chemical additives and reusable water, maximizing resource utilization. The synergy mechanism of CDOF + CDFU was fully validated in this project. The integrated and optimized treatment process achieved a high degree of automated control, reduced manual intervention, and improved treatment efficiency and stability, cutting operating costs by about 20%. The results won high recognition from the client and set a benchmark for the promotion of SINOKLE's technology in the industry. Project data show that the technology enables the oil and gas field to save about 5 million tons of water per year and reduce chemical procurement costs by nearly 10 million yuan, achieving remarkable economic and environmental benefits.
Fig. Before/after comparison of SINOKLE CDOF + CDFU fracturing flowback fluid treatment
