A New Approach to Produced Water

Produced water can be difficult to pump because it may contain solids, abrasive material and varying fluid properties that increase wear and reduce pump reliability. In this offshore oil-production application, AxFlow replaced repeatedly failing screw pumps with ATEX-rated Waukesha circumferential piston pumps designed to provide smooth, variable flow while handling solids and abrasive media more reliably.

Products:
Waukesha Universal Circumferential Piston Pumps.

Industry:
Off shore oil production.

Challenge:
To replace screw pumps used in a produced water process that were constantly breaking down due to abrasion and temperature damage. Any replacement pumps had to be capable of a variable pulse-less flow and offer a gentle pumping action.

Solution
ATEX rated Waukesha Universal II circumferential piston pumps running at 200 rpm, with flushed seals and internally coated,with Armoloy were used to replace the original pumps.

The Universal II pumps operate on the circumferential-piston principle whereby arc shaped rotor wings (pistons) travel in annular shaped cylinders machined in the pump body. The resulting long sealing path reduces slippage and produces a smooth flow of product without destructive pulses or pressure peaks, and without valves or complex parts.

Unlike centrifugal pumps, the Universal pumps can cope with high viscosity fluids and the large fluid cavities of the rotors, together with the large easy entry anti-cavitation ports allow efficient pumping of slurries and liquids containing solids of the nature encountered in produced water processing.

The skids also incorporated pulsation dampeners, pressure relief valves and the motor speed was controlled with VSD's to allow the pump to deliver a varying flow.