Water Injection Systems

Eta Process Plant designs, provides, and installs complete customized water injection packages with process guarantees for onshore and offshore applications. By optimizing the process design, we tailor height, weight, and power consumption to the specific application and location. These compact designs are ideal for offshore enhanced oil recovery projects, including fixed platforms, FPSOs, and TLPs.

Eta’s water injection systems can also be used for any seawater, river water, lake, or aquifer application.  

OUR TECHNOLOGIES

Deaeration for Water Injection

Koch-Glitsch’s high-performance deaeration packages optimize seawater deaeration processes by efficiently removing oxygen, preventing corrosion and ensuring long-term reliability in offshore oil and gas and environmental applications.

We bring our extensive experience in mass transfer technologies to support the oil and gas markets with dependable, customized solutions for seawater treatment. 

Vacuum Deaeration

The vacuum deaeration process is based on the reduced solubility of oxygen in water at reduced pressure. By reducing the vessel pressure to nearly full vacuum, extremely low dissolved oxygen levels can be achieved. The diameter and height of the tower are minimized by efficient contact between the gas and liquid phases. Eta uses its proprietary BETA RING® No. 2 random packing, which is specifically designed for the very high liquid loads and low gas loads in vacuum deaeration processes. This random packing allows higher liquid loads to be used with confidence. 

Multiple stages operating at progressively lower vacuum levels minimize the vapor extraction and increase vacuum pump efficiency. Water seals between each stage allow different pressures to be maintained. This design allows Eta to optimize every system, minimizing size and weight to reduce operating and capital costs. 

The vacuum is generated using liquid ring vacuum pumps and atmospheric air ejectors mounted as a single skid package. Two 100% vacuum pumps (duty/standby) are normally supplied with automated changeover to ensure continuous operation.

Gas Strip Deaeration

The gas strip deaeration process uses an oxygen-free gas to remove dissolved oxygen from the liquid stream. The low oxygen concentration in the gas creates a driving force for mass transfer, which reduces the concentration of oxygen in the treated waters. 

The water flows through a packed tower, countercurrent to the stripping gas, which is vented at the top of the column. Eta uses its own proprietary BETA RING® No. 2 random packing specifically designed for the very high liquid loads and low gas loads in deaeration processes, allowing higher liquid loads to be used with confidence. 

Gas consumption is minimized through Eta’s development of back-mixing factors that take into account the high liquid-to-gas ratios used in gas strip deaerator designs. 

These systems have no moving parts and are extremely reliable, which helps achieve continuous operation.

FILTRATION TECHNOLOGIES

Coarse Filters

Low-maintenance wedge wire coarse filter packages achieve continuous throughput of very large quantities of water. Backwash is initiated automatically on high differential pressure or by manual command. Coarse filters often process the entire platform utility water streams and can filter down to 50 microns. Water enters the filter vessel at the base, passing vertically upwards and radially outwards through the multiple wedge wire filter elements. During a backwash cycle, selected filter elements are isolated by a rotating element. The flow is reversed to drain, flushing each element individually.

Pressurized Dual-Media Fine Filters

Dual-media pressure filters use multiple layers of coarse and fine garnet and anthracite to provide the filtration substrate. The units normally operate with two or more duty filters and one standby filter, but other operating modes can be discussed. Backwash is initiated automatically on high differential pressure or by manual command. 

Fine Filters

Water enters the filter at the top, passes vertically downwards though the filter media, and achieves a filtration specification of up to 98% removal of particles 2 microns and larger. Filter aids may be used to increase efficiency.

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Ultrafiltration

Our ultrafiltration system uses hollow fiber membrane elements. Filtration efficiency of ≤ 0.02 μm, under typical conditions, for a range of feedwater from process streams to seawater. Ultrafiltration systems operate in multiple parallel trains to allow one train to backwash while maintaining the required filtrate output. General backwash, hypochlorite backwash, acid backwash, and flushing cycles are fully automatic and sequenced to maintain optimum filtration performance.

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Chemical Injection

Storage and dosing equipment for filtration aids, such as scavengers and biocides. 

Nanofiltration

Removes sulphates to prevent scale formation. 

Electrochlorination

Skid-mounted systems to generate sodium hypochlorite by continuous electrolysis of seawater. 

ADDITIONAL PLANT PACKAGES

Sour Water Strippers

Sour water containing hydrogen sulphide and carbon dioxide is treated in a stripping column by contacting the liquid stream with a sweet gas such as fuel gas. Eta is able to provide stripping units to achieve very low H₂S and CO₂ levels, even in oily waters (up to 1000 ppm wt oil). 

The proportion of H₂S that is available in its free form is principally dependent on the liquid pH and temperature. As H₂S and CO₂ are stripped from the water, the pH will rise, reducing the proportion of free H₂S in the liquid. Eta offers complete design and installation of turnkey sour water stripping systems.

Stabilizers for Crude Oil and Condensate

Stabilizers are installed for two purposes:

• Sweetening (reduce the H₂S content) 
• Removal of dissolved volatile gases to meet pipeline, storage, and transportation vapour pressure requirements

Eta offers the complete design of the stabilizer system for onshore and offshore applications.

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