Leistritz Pumpen GmbH

Leistritz Pumpen GmbH company headquartered in Nuremberg, Germany, has been manufacturing and selling screw pumps since 1924. The first Leistritz screw pumps were developed by Paul Leistritz for use as main pumps in the oil lubrication system of turbine generator bearings. Today Leistritz company with the world's widest range of screw pumps offers complete pump units and it is the reliable partner in the oil and gas industry. World-renowned reliability and efficiency of Leistritz screw pumps are based on state-of-the-art technology combined with strict quality control.

Leistritz screw pumps and systems for the oil and gas industry

The oil and gas industry is divided into three main sectors: exploration, production and refining. At the same time, production usually includes exploration works. The exploration and production sector includes search for profitable onshore and offshore oil and gas reservoirs, drilling of exploration wells and operation of wells producing oil, gas and liquid products of deposits or their mixtures. Today, more and more Leistritz universal twin-screw multiphase pump systems are being installed in the exploration and production sector to increase oil and gas yield.

Multiphase pumping systems

Leistritz multiphase pumping systems are used worldwide to pump raw products directly from wells with gas volume fractions (GVF) from 0 to 100 % at flow rates up to 5,000 m3 /h and differential pressures up to 150 bar. Compared to conventional units for oil production and treatment the multiphase production method does not require clumsy separators for well product, separate rotating equipment such as pumps and compressors and multiple pipelines to transport gas and liquid to processing facilities.

Design and operation principle

Leistritz multiphase pumps are twin-screw rotary positive displacement pumps and are designed according to requirements of API 676. Due to the design of double operating chamber, no axial forces are generated and pumps are hydraulically balanced. Screw pairs with the opposite thread direction are installed in a replaceable sleeve. The two screws made from one piece for maximum rigidity are not in contact with each other.

Screw profiles specially developed by Leistritz company ensure minimum vibration throughout the entire operating range of the pumps. Torque is transmitted from the driving screw to the idler screw through oil-lubricated pinion drive. This enables twin-screw multiphase pumps to pump products with high gas factor, contaminants and low API gravity crude oil. Pump shafts are sealed by either single or double mechanical seals which are exposed to suction pressure only. Leistritz twin-screw multiphase pumps are designed for pumping raw well products with a gas factor (GVF) from 0 to 100 %. In order to maintain the dynamic seal between the screw pair and the pump casing at high GVF values, small fluid flow shall be provided at all times. An external recirculation system for continuous fluid injection ensures uninterrupted operation at high GVFs and gas slugs and helps dissipate heat generated during compression.

Sizes of the external recirculation system can be adapted to actual operating conditions.