Along with maximizing petroleum yields, oil producers are challenged to make effective use of resources in order to keep costs down and stay in compliance with discharge regulations. While conventional separation and water treatment trains are effective, they are often large and heavy, can consume a lot of chemicals, and may create large volumes of waste sludge that may be costly to transport and discharge—especially for remote facilities and offshore rigs.
To meet these challenges, SAMCO has developed patented separation and water treatment processes that brings new efficiencies to the treatment of complex produced water, seawater, and hydrocarbon streams. SAMCO’s innovative water treatment processes deliver excellent hydrocarbon separation, and yield a high-quality treated water streams that are low in oxygen, dissolved solids, and other contaminants, making them suitable for enhanced oil recovery injection, and other reuse applications.
Treatment process for produced, desalted and flow back water
Liquid streams resulting from oil and gas recovery activities are notoriously difficult and costly to treat. SAMCO’s patented process for treating produced water, desalted, and flow back water offers a number of advantages over conventional water treatment technologies, and is adaptable to a number of settings, including on- and off-shore oil and gas extraction, hydrofracturing, and other applications. An overview of the basic process steps in the patented process is provided below:
The stream is first treated with one or more types of media filtration for removal of larger particulates. Following this initial pretreatment, the stream is then treated with an adapted ion exchange (IX) process for oil and water separation. This process can recover up to 95% of the oil present in a mixed stream, yielding a treated water stream with less than 5 ppm oil, and a recovered hydrocarbon stream suitable for commercial use. The water stream is then passed through one or more specialized membrane filtration units that remove additional hydrocarbons. This step helps to reduce the BOD and COD load on subsequent treatment steps, helping to minimize maintenance and ensure efficient system performance.
Following these hydrocarbon removal steps, the liquid water stream may be treated with conventional air stripping technologies for removal of VOCs and hydrogen sulfide (H2S). Additionally, if demanded by specific process needs, the stream may also be treated with adsorption media for removal of trace hydrocarbons.
Metals and contaminate ion removal
After initial separation steps, the water stream is treated with one or more ion exchange processes (IX). The IX unit(s) use specialty catalytic resins to remove targeted contaminants, including heavy metals like lead, copper, cadmium, and mercury, as well as other contaminate ions. IX separation offers a high removal rate of ionic contaminants, and additional removal of trace BOD, COD, and H2S can be achieved through application of oxidizing agents. After this polishing step, water is of sufficient quality that it may be discharged directly to a body of water, a deep distribution pipeline, or injected to a deep waste well, depending upon whether the stream meets relevant specifications for reuse, or applicable effluent regulations.
Contaminants that are separated from the stream are recovered as a concentrated waste stream during periodic IX resin regeneration. If desired, contaminant ions may be precipitated and dewatered minimize liquid wastes, as for a zero liquid discharge (ZLD) strategy.
Additional treatment options
With additional treatment, the stream resulting from the above processes can be reused for various applications, including enhanced oil recovery (EOR) injection, hydrofracturing, desalting, and clean water production, among others. Depending upon the chemistry of the treated stream and the desired reuse application, additional treatment by means of nanofiltration (NF), high- or low-pressure RO, and/or degasification may be deployed to ensure sufficient water quality for the intended process.
Oxygen reduction for reuse applications
Water used for EOR injection, hydrofracturing, and desalting applications must be of adequate quality in order to maximize hydrocarbon recovery and avoid excessive maintenance and equipment damage. In addition to managing levels of sulfate, hardness, metals, boron, and TDS, it is critical to reduce oxygen down to low parts per billion (ppb) levels to prevent oil degradation, corrosion, and clogs associated with bacterial growth in pipes and other equipment, or reactivity with down hole chemistry.
To meet this need, SAMCO has developed a patented three-step system for reducing oxygen in water used for hydrofracturing and EOR injection, as well as desalting applications. This innovative approach allows for reuse of produced water or seawater, while achieving the ultralow levels of oxygen needed to maximize production. An overview of the basic steps in the patented process is provided below:
SAMCO’s oxygen removal process begins where its produced, desalted and flow back water treatment process leaves off (see above). Following removal of metals and contaminate ions, the water stream is treated with a specialized low-pressure Membrane unit that allows oxygen gas to permeate but not water. This allows for removal of up to 90% of oxygen from the stream, down to less than 1 part per million (ppm).
The water stream is then routed to an IX polishing unit. This specialized IX unit leverages a palladium-doped resin and a reducing agent (e.g. hydrogen) to catalytically remove additional oxygen content from the water. This IX polishing step reduces oxygen levels down to less than 20 ppb.
Oxygen scavenger feed
If additional oxygen removal is needed, the stream can then be blended with an oxygen scavenger stream, such as hydrazine. This oxygen scavenger step removes trace oxygen content down to less than 5 ppb, and leaves residuals that are able to react with down hole chemistry for additional oxygen removal during use in EOR injection, desalting, or hydraulic fracturing applications.
Sour and acid gas separation
During hydrocarbon extraction processes, producers encounter mixed streams of petroleum, water and natural gas, each of which must be separated and refined for use, commercial sale, and/or discharge. Natural gas recovered from aging wells and EOR operations frequently contains high proportions of undesirable constituents, which can include high levels of hydrogen sulfide (“sour gas”), as well as carbon dioxide or other acidic contaminants (“acid gas”). Traditionally, the mix of methane , sour and acid gas were regarded as waste products and were simply flared—or burned—upon extraction.
In recent years, however, the practice of flaring has come under increasing public and regulatory scrutiny for its negative environmental impacts. To assist oil and gas producers in responding to these trends and improve extraction efficiency, SAMCO has developed a patented process for separating out sweetened natural gas, and treating waste streams for responsible discharge. An overview of the basic steps in the patented process is provided below:
First, extracted gas is treated with an innovative membrane gas separation process. This results in a Hydrocarbon liquids and sweetened gas stream that can be used within the facility or sold as a commercial product, as well as one or more waste streams. The sour and/or acid gas waste streams are then destroyed by means of a multistep process of incineration and scrubbing, wherein harmful constituents such as carbon dioxide and sulfur dioxide are converted to compounds that can be safely discharged back to the ocean or other outlet.
SAMCO’s patented systems offers a number of advantages over conventional treatment approaches, including:
Typical equipment used for removal of solids and oil-water separation, like gravity separation devices (e.g. skim tanks, API separators, plate coalescers) or gas flotation units, are generally very heavy and large, and some types are also sensitive to motion. Because of these limitations, they are typically not viable for floating rigs, or at facilities where space is a concern.
In contrast, SAMCO’s solutions are compact and lightweight because they leverage innovative membrane filtration and IX technologies. These separation and water treatment technologies are designed to maximize treatment capacity in a small footprint, allowing them to make more efficient use of space than conventional separation technologies.
Conventional water treatment approaches can require lots of chemicals to function, which can add up to high costs for sourcing and transporting consumables, as well as high costs for treating and disposing of complex waste streams. SAMCO’s patented solutions, on the other hand, require less chemical use, while still delivering high removal rates for a broad range of contaminants, including sulfates, boron, suspended solids, dissolved solids, H2S, and oxygen. In short, SAMCO’s treatment and separation solutions reduce sludge and wastewater discharge volumes by producing treated streams that may be reused for EOR injection, desalting, and hydrofracturing, or safely discharged to the environment.
Improved hydrocarbon recovery
Conventional technologies used for oil and water separation typically require the use of chemical additives that can render oil and gas streams unrecoverable for commercial sale or use. SAMCO’s patented technologies are designed to work with minimal chemical addition, thereby increasing hydrocarbon recovery rates up to 95%.
How SAMCO can help
SAMCO has over 40 years’ experience in the design and manufacture of custom water treatment systems for a range of industries and applications, so please feel free to reach out to us with your questions.
Get in touch with us here to set up a consultation with an engineer or request a quote. We can walk you through efficient water treatment solutions that reduce waste and enhance reuse capabilities for produced water, seawater, and other streams.
Head on over to our blog to learn more about our other separation and wastewater treatment technologies articles that might be of specific interest to you include:
- Why Your Industrial Facility Should Plan for Water Shortages Sooner Rather Than Later
- What Is Brine Waste, and How Can It Be Treated for Reuse or Disposal?
- What Technologies Usually Make up a Brine Water Treatment System
- Five Ways Your Industrial Facility Can Conserve Water and Plan Ahead for Shortages