achieve their desired flow and pressure requirements but also improve efficiency of their Oily Water Separators .
IMPROVING EFFICIENCY OF OILY WATER SEPARATORS
Oily Water Separators separate water and oil firstly by pumping the fluid through filters to capture droplets , but also by using the liquids natural characteristics -its specific gravity to separate oil , with oil rising above the water and sludge settling at the bottom of tanks .
As oil and water do not mix , when it is pumped it forms an emulsion . If this mixture is pumped with high amounts of shear - produced by some pump types such as centrifugal , the droplets can split forming multiple smaller droplets making separation more difficult .
The efficiency of Oily water separators is improved by utilising progressing cavity pumps , as its design affects oil particles the least due to its low shear movement , meaning separation equipment captures a greater amount of undamaged oil droplets .
Progressing Cavity pumps were rated by the SPE ( Society of Petroleum Engineers ) in Paper SPE18204 as the preferred pump to use for oil droplets which were found to be disturbed the least during handling against a comparison of lobe , vane and screw technology .
Progressing cavity pumps were chosen as the ideal technology for this project as not only do they handle the oil droplets gently but they produce a constant volume of flow at varying pressures , are affected very little by changes in viscosity and can handle solids without issue .
This is important due to the changing nature of the application . When oil is extracted , initially the produced water content of a well will be kept as low as possible to reduce the amount of oily water treatment required , with volumes increasing as it becomes inevitable due to the lowering level of oil within a well as it is extracted . The amount of water present within a well is often referred to as oily water cut .
WHAT IS OILY WATER CUT ? Oily water cut is the amount of water produced in a well compared to the amount of oil or solids present which is often expressed as a percentage , with a 30 % water cut meaning 30 % of the extracted volume contains 30 % water
We specified and supplied two Horizontal Progressing Cavity pumps perfect for the low shear transfer of Oil / Water Mix , capable of a flow range of 50-200 L / min with a performance and hydrostatic test to 18 bar . Due to the presence of solids the Stainless-Steel Rotor was hard chrome plated to protect it from abrasion , prolonging its lifespan .
The units were fitted with PT100 Dry run protection sensors , to ensure pumps could not be ran dry , and IP65 ATEX variable speed motors due to the sites exposed location .
If you have an ATEX application and are unsure of the correct solution , contact North Ridge Pumps on 01773 302 660 or visit www . northridgepumps . com to see how we can help .
Progressing cavity pumps were chosen as the ideal technology for this project as not only do they handle the oil droplets gently but they produce a constant volume of flow at varying pressures
For further information , please visit www . northridgepumps . com
Issue 56 PECM 17