With the continuous global demand for energy, the pace of exploration and development of oil resources is accelerating. However, a large amount of wastewater is generated in the process of oil field exploitation. These wastewaters are complex in composition and contain a large amount of oil, suspended matter, chemicals, heavy metals, organic pollutants, etc. Direct discharge without treatment will seriously pollute water and soil, and even cause potential harm to human health. Oilfield wastewater is mainly divided into three categories: oil production wastewater, water injection return fluid and drilling wastewater. Among them, oil production wastewater accounts for the highest proportion, accounting for more than 80% of the water consumption of oil production, and its treatment has become one of the core tasks of oilfield environmental protection management.
Under the pressure of “dual carbon” goals and environmental supervision, oilfield wastewater treatment is no longer just about meeting emission standards, but also pursuing resource utilization and efficient emission reduction. Therefore, the selection of efficient, stable and highly automated separation equipment has become an urgent need for oilfield enterprises. In this context, the decanter centrifuge, as a mature and reliable solid-liquid separation technology equipment, is increasingly being used in the efficient treatment process of oilfield wastewater, playing a vital role.
Decanter Centrifuge: Separation Center in Oilfield Wastewater Treatment
Working Principle
Horizontal screw centrifuge, full name horizontal screw discharge sedimentation centrifuge, uses the centrifugal force field generated by the high-speed rotation of the material to separate the solid particles in the mixed liquid from the liquid phase. Its core structure is the coaxial counter-rotation of the drum and the screw conveyor:
After the raw materials enter the drum, under the action of strong centrifugal force, the solid particles quickly settle to the inner wall of the drum;
At the same time, the screw conveyor continuously pushes the deposited solids to the conical end of the drum for discharge;
The clarified liquid is discharged through the overflow port to achieve continuous and stable solid-liquid separation operation.
This structure gives the horizontal screw centrifuge the advantages of high efficiency, continuous, automatic slag discharge, high separation accuracy, and strong adaptability. It is especially suitable for treating complex wastewater with high viscosity and high solid content, such as oilfield wastewater and drilling mud.
Process flow of decanter centrifuge in oilfield wastewater treatment
In modern oilfield wastewater treatment systems, decanter centrifuges are generally located in the key link of “solid-liquid separation”, and cooperate with other treatment units to form a complete process chain. The typical process flow is as follows:
1. Pretreatment link
The wastewater first passes through the screen, sand settling tank, regulating tank, etc. to remove large particle impurities, adjust the water quality and water volume, and reduce the impact on subsequent equipment.
2. Dosing demulsification
According to the emulsified oil composition, demulsifier or coagulant is added to make the oil and water stratified and the particles agglomerated.
3. Decanter centrifuge separation
Pump the wastewater into the decanter centrifuge;
Achieve rapid separation of solid-liquid (some equipment supports three phases);
The dehydrated sludge is discharged by spiral push, and the clear liquid enters the next treatment unit.
4. Post-treatment stage
The clear liquid can enter the flotation, filtration, biochemical or membrane system for further purification, and finally reuse or meet the discharge standards.
This technology can significantly improve the system’s processing capacity and stability and is a solution commonly used in modern oil fields.
Core advantages of decanter centrifuge
1. Efficient separation, adapt to high oil and high solid conditions
Decanter centrifuge design supports high solid content, high viscosity, high emulsification materials, especially suitable for complex wastewater in oil fields, solving problems that traditional equipment cannot handle.
2. Continuous operation, automatic slag discharge
It can operate continuously for 7×24 hours, and adopts automatic differential control system to realize slag and liquid discharge operations without manual intervention, greatly reducing labor costs.
3. It can realize oil-water-solid three-phase separation
Some models of decanter centrifuge support three-phase separation technology, and output oil, water and slag separately, which is convenient for subsequent resource recovery or treatment.
4. Small footprint and convenient system integration
Compact structure and modular design are easy to install in limited space areas such as oil fields and drilling platforms, and meet the needs of field and mobile operations.
5. Corrosion-resistant and wear-resistant, long service life
The contact medium part adopts anti-corrosion materials such as 316L stainless steel, duplex steel or ceramic coating, which adapts to the high corrosion and high scouring environment of oil fields.
6. Intelligent control, energy saving and consumption reduction
Equipped with PLC control system and variable frequency drive technology, it realizes functions such as intelligent start and stop, differential speed adjustment, and automatic alarm, which is energy-saving and efficient.
Under the increasingly stringent environmental protection requirements for oilfield wastewater treatment, enterprises are no longer satisfied with “standard” emissions, but are pursuing efficient treatment, resource recovery, energy conservation and emission reduction, and green development. Decanter centrifuges, with their excellent separation capabilities, continuous and stable operating characteristics and good adaptability, have become the backbone of the oilfield environmental protection system. As a professional decanter centrifuge manufacturer in China, we have always focused on the research and development and implementation of high-difficulty material separation technology, and have accumulated rich experience in oilfield projects in many parts of the country. We provide one-stop services from equipment selection, solution design, on-site commissioning to long-term maintenance to help customers achieve cost reduction, efficiency improvement and sustainable development.
If you are looking for efficient separation equipment suitable for oilfield wastewater treatment, please contact us for detailed information and customized solutions. We will wholeheartedly provide you with professional support!
