Separation of oil and water can be achieved more efficiently by use of cyclonic technology compared to conventional gravity separators. The InLine DeWaterer is a compact cyclonic unit for ultra-compact separation of oil and water. This device combines high efficiency with low pressure drop in a compact design.

Applications

The primary application area for the technology is debottlenecking applications. A large number of oilfields experience capacity limitations due to unsatisfactory oil-water separation performance as the field matures and the water production increases. The InLine DeWaterer offers a very cost efficient way of retrofitting such processes. The technology can also be applied for new build applications, where the operator wants to save space and weight of the processing modules by using compact oil-water separation technology. The technology is also being developed for subsea separation systems. The unit is currently qualified for applications where the inlet flow is water continuous, typically for water concentration higher than 50 percent. Expansion of the operating window of the technology which also will allow for separation of oil continuous mixtures is currently ongoing.

Principle of operation

The InLine DeWaterer is an axial flow cyclone that uses a specially designed swirl element that converts pressure into a swirling flow with low energy loss and shear. The innovative swirl generation method leads to a stable flow profile in the cyclone, high efficiency and lower pressure drop that enables the high separation efficiency separation of a bulk mixture of oil and water. An oil core is formed by the oil droplets moving to the center further downstream in the cyclone. The separated oil is removed through a reject (overflow) opening. The clean water leaves the cyclone through a water outlet (underflow). The unit can be specially designed for various applications, covering applications with various water-oil contents, as well as with various inlet gas concentrations.

Features and Benefits

• Proven technology: The InLine DeWaterer has been tested with many different oils, including heavy oils with API grades of 15 to 20. Qualification programs are carried out with several operators.  
• Compact, efficient separator: The DeWaterer achieves oil-water separation within a substantially smaller volume than a conventional gravity separator. This is achieved due to the high G-forces caused by the swirling flow. The high G-forces also enable separation of mixtures/emulsions that do not break in normal gravity separators.
• Custom design: Each system is designed according to the client’s specifications (operating envelope, pressure and temperature rating, construction materials, etc.). Our specialists work closely with the operators to tailor-make the solution for each particular application.
• Wide operating envelope: The inlet oil content can be from one percent up to 50 percent and the system can accommodate flow fluctuations. The unit can accept inlet gas faction up to 30 percent without significant degradation in performance. The inline dewaterer shows no degradation of separation performance at high turn downs of 50 percent or more.
• Minimal maintenance: The unit, which has no moving parts, features large reject openings to minimize the need for maintenance and cleaning. The minimum openings are large giving low risk of clogging. The velocities are relatively low such that wear of the unit will not affect the lifetime of the unit.
• Flexible design: The total capacity is determined by the number of cyclone liners in operation. For highly variable flow rates, several InLine DeWaterer units can be installed in parallel and brought on stream as required to ensure that they always operate close to maximum efficiency.  Depending on the inlet oil content and the required separation efficiency, a single-stage or two-stage design may be selected.
  

Performance Expectations

The DeWaterer has been extensively tested to map the operating performance at various conditions. Typical performances are: