The particulate size
The majority of the filtration work carried out by oilfield filtration service companies is the removal of solids contamination from brine during a wellbore clean-up at the completion stage.
The contamination in question is predominantly from the mud residue, most of the solids in the mud residue are under 20 micron.
Unfortunately it’s the smaller particles that cause the biggest challenge to remove; larger particles can lend themselves to the filtration process.
Particles filtered within oilfield operations are too small to be represented in millimetres, the unit size used is the Micron (µm), this term has been changed to Micrometre, which is the equivalent SI unit (the term micron however is still commonly used in the oil industry). There are one thousand microns in a millimetre, one million in a metre.
The Micron Ladder
The micron ladder demonstrates the sizes of various materials expressed in microns, beach sand varies in size up to 1000 micron, tobacco smoke is about one micron. The line at 30 micron indicates that 90% of all contaminating solids removed the service company are below 30µ in size. The human eye can see down to 40 micron.
Dutch Filtration design and manufactures DE filtration equipment such as VPL (Vertical Pressure Leaf Filter Unit and Filter Press) which removes dirt particles in completion fluids, workover fluids, wellbore clean up, down to 5 micron nominal at high flow rate and high dirt loads.
The dual cartridge filter unit (also known as Dual pod, Duplex filter, Twin pod filter, Twin filter unit) can be fitted with a wide range of filter element to remove particles down to 0.5 micron and polish the fluids from the filter press or VPL unit. All equipment is DNV2.7-1 certified by DNV.