Classification of oily sludge

1. Oily sludge produced during crude oil exploitation. In the drilling operation, when the oil layer is detected,
 the operation of drilling and well testing may cause oil spill or blowout and produce oily sludge due to the action of ground pressure.
 In the process of crude oil production, crude oil detection, plugging, tubing fracture, workover operations, etc., may produce landing oil mud.
This oily sludge has the characteristics of large oil content, fine particles, large viscosity and difficult water removal.

2. Oily sludge produced in the gathering and transportation process of oil fields.
Oil field gathering and transportation is the process of collecting and treating the crude oil produced by each oil well in the oil field and transporting it to the oil depot or the export station respectively.
The gathering station is a place where oil, water and gas are separated from the extracted crude oil, and the sewage station treats the separated water and refills the oil well.
The gathering station and the sewage station are called the combined station. In order to maintain the formation pressure, most of the crude oil is injected with water first and then surfactant. After the formation pressure exists, the crude oil is transported to the surface through the oil well. With the deep exploitation of the oil field, the water content in the produced oil is increasing. Therefore, the oily sludge produced in the oil-water separation process of the joint station usually has a high oil content and water content, and a low solid content, which not only has asphaltene, aging crude oil, bacteria, but also has corrosion inhibitors, scale inhibitors, flocculants and other agents added in the sewage treatment process. There are two sources of oily sludge in the joint station: one is the bottom sludge of crude oil storage tank, settling tank and sewage tank; The second is the oily sludge formed by the overflow of sewage storage tank.

3. Oily sludge produced by the refinery sewage treatment process. Oil-bearing sludge in oil refinery, commonly known as "three mud", has a large output, and usually has the characteristics of complex composition, difficult degradation, difficult settlement, difficult concentration and difficult treatment.

Characteristics and hazards of oily sludge

Oily sludge density is generally larger than water, oil content is high, generally 10%-50%, water content is 50%-90%, viscosity is large,
dehydration is difficult, is a black viscous semi-fluid. The composition of oily sludge is complex, not only with a large number of aging crude oil, asphaltene,
wax, colloids, bacteria, solid suspended matter, salts, corrosive products, acid gas, etc., but also in the production process added corrosion inhibitors,
coagulants, fungicides, scale inhibitors and other water treatment agents, is one of the main pollution sources in the oil industry

Oily sludge is rich in organic matter, salt, nitrogen, phosphorus, sulfur and other nutrients. If it is directly discharged into the surface water body or under the action of precipitation, the organic matter and ammonia nitrogen will consume a large amount of oxygen in the water body, resulting in eutrophication of the water body and seriously affecting the balance of the aquatic ecosystem. In addition, oily sludge also contains heavy metals such as copper, zinc, chromium, cadmium, mercury, lead and pathogenic bacteria, parasites (eggs), polychlorinated biphenyls, dioxins, radionuclides and other toxic and harmful substances that are difficult to degrade, which will not only pollute the environment, but also affect human health, leading to many fatal diseases, and even carcinogenic, teratogen, mutagenic effects. Therefore, in 1998, the State Environmental Protection Bureau classified oily sludge as waste mineral oil and mineral oil waste (HW08 item) hazardous solid waste, and required harmless disposal before discharge.

The processing process is: The material to be treated is fed by the belt conveyor into the spiral sand washing machine,
the sand treated by the spiral sand washing machine enters the fine particle sand removal machine, the fine particle sand is crushed and cleaned,
part of the oil is separated into the oil storage tank by the scraper, the sediment is transported to the vibrating screen by the centrifugal pump for dehydration,
 and the particles larger than 0.5mm are separated. >74 micron<0.5mm particles and sediment are processed by centrifugal pump into cyclone,
<74 micron particles are separated and dehydrated by centrifuge, and <2 micron materials are processed by air flotation machine.
The sand after air flotation treatment is discharged and dried, and the water after air flotation treatment is reused by spiral sand washing machine.
The oil sewage of the spiral sand washing machine enters the oil sand separation tank for treatment. After treatment,
the oil enters the oil storage tank for recovery through the scraper. The fine sediment after precipitation is transported to the vibrating screen by the centrifugal pump.
 

sludge sand treatment最先出现在Solids Control System, Slurry Treatment Plant, HDD mud recycling system-KOSUN。

Oily sludge refers to a mixture of oil, water, and solids. KOSUN can provide complete sets of equipment for oily sludge treatment to treat the sludge and recover oil and water. The thermal washing technology for oily sludge treatment can achieve lower-cost solid disposal and maximize oil recovery.

Oil-containing sludge is the main pollutant generated during the production process of oil, including crude oil extraction, storage, transportation, processing, and treatment of produced water. Oil-containing sludge is typically a stable suspension emulsion system consisting of water-in-oil (w/o), oil-in-water (o/w), and suspended solids. It has poor dewatering effect and its composition and properties are influenced by factors such as wastewater quality, treatment processes, and additives, resulting in high variability and difficulty in treatment. The oil content of oil-containing sludge varies significantly, and some of it has potential for recycling. Additionally, oil-containing sludge contains harmful substances such as heavy metals, posing a risk of environmental and radioactive pollution.

Oil content in oily sludge is relatively high, making it a valuable resource in waste. If not properly recovered, it would result in significant material waste. Storing or landfilling oily sludge occupies a large amount of arable land while polluting the surrounding environment. The volatile components of oil in oily sludge can pollute the air when released. When rainwater carries oil from the sludge into water bodies, it causes severe pollution and disrupts the aquatic ecosystem. The petroleum in the sludge can harm the soil’s microbial and plant ecosystems when it enters the soil. Furthermore, many harmful substances in crude oil have mutagenic and carcinogenic properties, causing serious harm to human health through direct and indirect exposure. Therefore, it is crucial to properly treat oily sludge using suitable methods to achieve both resource recovery and environmental protection goals, considering both environmental protection and resource recycling perspectives.

The large-scale thermal washing and skid-mounted treatment system for oily sludge produced by Xi’an KOSUN consists of pre-treatment module, oil-sand separation module, screening module, oil-water separation module, etc. The system aims to address the treatment of waste oil sludge generated during drilling processes. The system has a processing capacity of 30t/h, and the oil content in the solid phase after treatment can reach less than 3%. The thermal washing and skid-mounted treatment system for oily sludge achieves good treatment results and effectively reduces the cost of solid waste treatment, achieving harmless and resource-oriented disposal. It is worth mentioning that the water in this system is recycled, resulting in minimal water consumption, environmental safety, and no secondary pollution.

Application scope:

Bottom sludge from oilfield central stations, aged sludge from oilfield central stations, land-based oil sludge, complex mixed sludge from industrial waste pits in oilfields, intermediate sediment isolation layers from natural settlement and dewatering in oilfield water treatment processes, oil-containing sludge generated during oil drilling oil-based cuttings oil removal processes, bottom sludge from offshore oil tanker compartments, oil sludge residue discharged from separation machines for ship fuel oil and lubricants, oil sludge treatment in petrochemical plants, waste lubricating oil and emulsified oil treatment, treatment of other mineral oil sludge and sediment, and storage of coal tar in coal chemical industries.

Oil Sludge Thermal Washing and Disposal System最先出现在Solids Control System, Slurry Treatment Plant, HDD mud recycling system-KOSUN。

Sludge has been listed in the "National Hazardous Waste List" of waste mineral oil (HW08 category), and relevant laws such as the "National Clean Production Promotion Law" and "Solid Waste Environmental Pollution Prevention Law" also require that sludge must be harmless treatment.

Xi 'an KOSUN closely follows the national policy, vigorously develops green and environmentally friendly sludge treatment and soil remediation equipment,
 combines vibration separation technology, centrifugal separation technology and fluid mechanics to solve the problem of solid-liquid two-phase separation in the process of environmental protection waste treatment,
 and reduces pollutant emissions through follow-up treatment functions. Recycle available resources and meet local government emission standards and environmental requirements

Oily sludge hot wash Processing system最先出现在Solids Control System, Slurry Treatment Plant, HDD mud recycling system-KOSUN。

You can see the detailed processing of the oil sludge, and the good result of the treatment.

Oil sludge treatment plant最先出现在Solids Control System, Slurry Treatment Plant, HDD mud recycling system-KOSUN。