A German energy supplier had initially used a geological horizon for gas storage but then decided to extract crude oil from the same deposit.

Therefore, a suitable extraction system had to be acquired for transporting the multiphase mixture with a high gas content to the surfaced rom 1,200 m below.

Due to the extreme conditions, a special pump technology was required: centrifugal pumps with submersible drive were not suitable due to the high risk of failure from gas lock, while the progressing cavity pumps with above-ground drive, as commonly used in Central Europe, posed the risk of a blowout on the surface. This prompted a detailed production and profitability analysis which showed that a conversion from gas to oil production for this bed was economically viable.

Extreme conditions

The extreme conditions on site, however, presented very high requirements for the pump design: as the medium was a multiphase mixture with a very high gas content, the usual centrifugal pumps with underground drive were not an option.

With a very high free gas content, this type of pump always presents the risk of all impellers filling up with gas. Therefore, it was extremely likely that a centrifugal submersible pump would have failed in this application due to the so-called gas lock.

The progressing cavity pumps, which are normally used in Central Europe until now, have been systems with above-ground drive. These units have a dynamic seal on the surface which has a significant disadvantage in case of extreme pressure increase on the intake side: the seal can become overloaded and trigger a blowout.

Special feature

To exclude this risk, Netzsch decided on a progressing cavity pump which is driven underground with the Netzsch ESPCP. The special feature of this pump is that the rotor is not driven via a very long rod, but rather the rotor-stator combination and the motor are sunk into the well.

The motor is connected directly to the rotor via a short flexible rod. All radial and axial forces of the rotor are absorbed by a special underground bearing housing. In addition to this, the dynamic seal is also located in the 1,200 m deep well. This moved all critical components of the pumping solution below ground, precluding environmental impact from leaks above ground.

NETZSCH Pumps Canada, Incorporated LLC

NETZSCH has served markets worldwide with Progressing Cavity, Rotary Lobe, Multiple Screw and Peristaltic Pumps and accessories, offering upstream, midstream and downstream systems and skid solutions for the oil industry. Our fully integrated processes for all components give you added assurance of our depth of knowledge to provide you solutions for all of your challenging pumping applications. As the world’s market leader of Positive Displacement Technology, our innovative, premium quality products are known, used and valued globally.