Fracturing Flowback Fluid in Xinjiang: Zero-Chemical Treatment at 360 m3/d

A Stream That Punishes Chemical-Heavy Treatment

Fracturing flowback fluid is a difficult combination: complex composition, high viscosity and severe emulsification. Treatment routes that depend on large reagent doses handle it, but they pay twice, once for the chemicals and once for the secondary pollution and hazardous waste disposal those chemicals create. Against tightening environmental standards in the Xinjiang region and an internal requirement to cut cost while raising efficiency, that cost structure stops being acceptable.

SINOKLE took a different route on the strength of independently developed core processes and patented technology, and the result has shifted how flowback fluid is treated in the blocks where it has been deployed: zero chemicals, low energy consumption and intelligence, rather than more reagent and more sludge handling.

Two Mechanisms, One Chain

The technology system is built on pure-physical separation plus efficient catalytic oxidation, which inverts the traditional idea of treating chemicals with chemicals. CDOF ozone catalytic oxidation handles deep gel breaking and viscosity reduction. CDFU swirl dissolved air flotation removes oil and solids efficiently. Fine filtration polishes the stream, and the skid-mounted equipment can be truck-mounted to move with the well. Filtered water meets the requirements for reuse in fracturing fluid preparation.

CDFU. High-gravity swirl dissolved air flotation is a new generation of flotation technology pioneered in China that integrates swirl centrifugal separation with ultra-fine bubble flotation. High-speed swirling generates a strong centrifugal field that gathers fine oil droplets and particles in advance, while the system produces large numbers of micron-sized bubbles that attach firmly to pollutants. Swirling and buoyancy then lift the loaded bubbles out. Demulsification is purely physical, no flocculant is added, oily sludge generation is eliminated at source, and de-oiling efficiency holds stable at 90% or more.

CDOF. Refractory dissolved organic matter and residual chemical agents are the reason a physical stage alone is not sufficient. The patented CDOF unit integrates multi-stage ozone catalytic oxidation, hydrodynamic cavitation and swirl dissolved air flotation in a single sealed, pressurised reactor. Oxidation efficiency multiplies, polymers such as guar gum are rapidly cleaved and degraded, and flotation separation completes at the same time. Ozone reaction time is short, within 15 minutes, with a utilisation rate as high as 99% or more, while energy consumption and operating cost are only 30% or less of traditional ozone oxidation technology.

Materials. The processes above depend on media that can survive the duty. SINOKLE applies atomic layer deposition (ALD) technology to carry out atomic-precision hydrophilic and oleophobic modification of the filter media surface, which improves filtration precision and anti-fouling capability together.

What Happened in the Field

The first fracturing flowback fluid treatment project in the Xinjiang oilfield adopted a CDFU plus activated filter media filter process at a treatment capacity of 360 m3/d. The project solved the industry pain point of difficult gel breaking at low temperatures, achieved all-weather stable operation with effluent reuse, and saved most of the customer's chemical and sludge disposal cost. Extended operation across multiple Xinjiang blocks has confirmed the performance rather than merely demonstrating it.

The Constraint That Shapes Every Flowback Design

Flowback fluid treatment has one property that separates it from produced water and refining wastewater: the water appears where the well is, and the well moves. A conventional plant with settling basins, reagent dosing systems and sludge handling cannot follow a fracturing spread across a field development, and trucking the fluid to a central facility adds cost and risk at scale. That single constraint is why the SINOKLE configuration is skid-mounted and designed to be truck-mounted. It also explains why reagent reduction is worth more here than in a fixed plant, since every chemical delivered to a remote pad has to be stored, dosed and accounted for on site, and every litre of sludge produced has to be taken away again.

Once those two requirements are accepted, the process architecture follows. Physical separation removes the need for a reagent supply and dosing control loop. Catalytic oxidation with a short reaction time keeps the skid small enough to move. Automatic control keeps an unattended unit stable between visits. And effluent quality suitable for reuse in fracturing fluid preparation removes the water-hauling cost altogether, which is usually the largest single saving available on a development programme.

Counting the Return in Three Dimensions

Economically, the zero-chemical model ends continuous reagent consumption and high hazardous waste disposal fees, the low-energy design lowers long-term operating cost, and skid-mounted modular construction shortens the project schedule and reduces land occupation and infrastructure investment. Comprehensive calculation puts lifecycle operating cost more than 70% below traditional processes. Operationally, the fully automatic intelligent control system supports remote monitoring and unattended operation, which lowers safety risk and labour intensity, while consistent treatment performance protects reinjection water quality and therefore formation pressure. Strategically, the model changes the direction of oilfield environmental governance, from passive end-of-pipe treatment to proactive in-process resource recovery, which is a larger shift than any single equipment upgrade.

Why the Approach Travels

What makes this configuration transferable is that it does not depend on a favourable site. Low-temperature gel breaking difficulty, high viscosity and variable composition are the normal condition of flowback fluid rather than an exception. Once the process chain is anchored on physical demulsification and catalytic oxidation instead of reagent chemistry, the same modules can be re-sequenced for a different water. From verified operation in the Xinjiang Gobi to projects under complex conditions elsewhere, the pattern SINOKLE has established is that zero chemicals, low energy consumption and intelligence is a repeatable engineering position rather than a slogan, and it is the position every new flowback project should be measured against.