Introduction and user benefits
Conventional centrifugal pumps break oil droplets while pumping produced water. The consequence is reduced efficiency of downstream treatment processes. Positive displacement pumps (PDP) are sometimes used to avoid breaking droplets. PDPs have, however, other mayor drawbacks such as expensive and frequent maintenance requirements, high noise levels and vibrations. This makes centrifugal pumps the more robust and attractive solution. Typhonix Pumps combine the low shear features of PDPs (i.e., avoids or reduces breaking oil droplets) with the operational robustness and reliability of centrifugal pumps.
Overall user benefits of Typhonix Pumps are:
- Increased reliability, reduced mechanical maintenance and increased lifetime.
- Normally no need for noise protection enclosures or pressure relief valve systems.
- Smaller and lighter than progressive cavity pumps in most applications.
- More energy efficient produced water treatment and increased capability to handle process upsets and variations in produced water quality.
- Cleaner produced water and reduced oil and chemical discharges to the sea.
What makes Typhonix Pumps so special?
Generally speaking, Typhonix Pumps are high hydraulic efficiency multistage centrifugal pumps with an innovative Low Shear trim. This means that the layout and configuration of the individual stages are custom designed to control shear forces, minimize oil droplet breaking and optimize droplet-droplet coalescence. The Low Shear Trim is specially engineered for each individual application, considering factors such as the head requirements, crude viscosity and produced water treatment system requirements. Figure 1
shows a principal sketch of the Typhonix Pump internals.
Figure 1. Principal sketch of the Typhonix Pump internals.
The Typhonix Pump is a result of several years of development work, through Joint-Industry-Projects, financed by oil companies and the Norwegian Research Council. Initially, the objective was to develop a pump possessing the low shear feature of a positive displacement pump (new, with minimal slip flow), combined with the operational benefits of a centrifugal pump. During the development work, innovative new solutions to control turbulence and shear forces were found.
With these new solutions, Typhonix Pumps not only reduce droplet break up, but are also designed to let the oil droplets collide and coalesce. Coalescence means that two small droplets come together and form one big droplet. These larger droplets are much easier to separate, meaning that a pump with coalescing features will increase the efficiency of downstream water treatment.
During the development work, comparative tests with other commercial pump types were performed. These tests involved a variety of test conditions, including light, medium and heavy crudes, low and high oil concentrations, and small and large inlet droplet sizes. The tests demonstrated how positive displacement pumps generally maintained the droplet size, while the single-stage centrifugal pump always broke the droplets further. Typhonix Pumps either maintained or enlarged the droplet size, depending on the operating conditions.