OILFIELD WATER MANAGEMENT
Flargent offers solutions to remove production water and suspended solids from hydrocarbons. Recovered water is later reinjected into the formation, both as a means of final disposal or as part of a secondary recovery process.
FREE WATER KNOCKOUT DRUMS
Flargent manufactures a line of free-water knockout (FWKO) units, designed to separate free water in oil and gas streams exiting the well or from upstream primary storage batteries. They are typically placed upstream of treatment plants and capable of knocking out up to 95% of free water in incoming crude, allowing up to 30% free water in their discharge. All oil, gas, and water treatment operations take place downstream from this equipment.
FWKOs work on the principle of mechanical separation of the emulsion, with high-tech internals that favor coalescence between the different phases and reduce residence times.
Flargent sells FWKOs as an assembly or can provide the components and technology for equipment supplied by third parties.
FLOTATION UNITS
For separating particles of up to 20 parts per million of free hydrocarbons from water, Flargent manufactures a line of flotation units that are composed of chambers where, through an energy input, hydrocarbon droplets are made to rise and form a froth that is then separated from the water by a skimmer.
The external energy input, which allows the considerable reduction of residence times and the size of the chambers, is supplied by mechanical or hydraulic means. Mechanical flotation is realized by a series of rotors installed at the base of the equipment that generate turbulence and bubbles to stimulate the flotation of the hydrocarbons. Hydraulic flotation, on the other hand, has the same effect without any moving parts, by recirculating pressurized gas through nozzles in the flotation chambers.
Flargent manufactures flotation units based on each of these technologies, which are common in water treatment and injection plants used in secondary recovery processes.
GRAVITY GRANULAR-MEDIA FILTRATION
To remove water contaminants, such as sediments and suspended particles, and properly dispose of the residue, Flargent offers units that consist of dual or multi-layered bed filters. The layers of granular media are placed so that the top layer (anthracite) traps the largest particles and the bottom layer (sand), the smaller ones.
The finer granular media is the densest and remains at the bottom of the filter, while the coarser granular media is less dense and remains on top. Filter cleaning is executed by reversing the water flow, known as “backwashing”. This re-establishes bed conditions and, due to the difference in densities, the granular media returns to their natural position.
WALNUT SHELL FILTERS
In the last stage of water treatment for secondary recovery, Flargent manufactures filters with walnut shell beds. These retain approximately 98% of hydrocarbons and solids greater than 5 microns dispersed in the water flow.
Once saturated, these beds are regenerated by backwashing. This is a PLC automated operation, based on the differential pressure across the bed, or at preset intervals. The backwash pumps are mounted on the same skid as the filtering units.
PLATE COALESCERS
To separate two immiscible liquids, Flargent manufactures plate coalescers that are typically used for hydrocarbon-water mixtures in liquid-phase or three-phase field separators. When the liquid phases collide against a plate pack, the denser phase coalesces, forming larger droplets which fall to the bottom of the container.
In the case of highly viscous mixtures that can contain solids, Flargent recommends the use of parallel-plate coalescers. Plate coalescers can be used together with free-water knockout drums (FWKO), where they are placed immediately downstream from the oilwell.
DEOILING HYDROCYCLONES
Flargent recommends using deoiling hydrocyclones as the first stage in the process line of water treatment systems.
Deoiling hydrocyclones are static units used for gross particle removal. In a deoiling hydrocyclone, a fluid with suspended particles is subjected to a centrifugal force created by its own kinetic energy; this is the basic principle of centrifugal sedimentation. To achieve this separation correctly, special high-pressure pumps are required to deliver the necessary energy to the fluid. These pumps are part of the unit.
Deoiling hydrocyclones are similar in function to skimmer tanks, but with many advantages as to the space required. Skimmer tanks are over 10 meters in diameter, with stainless steel internals that allow the skimming of the hydrocarbon phase. In addition to their high cost and long on-site manufacturing time, skimmers take up a large amount of room. Bearing this in mind, in offshore applications, deoiling hydrocyclones are the only option due to their small footprint.
Flargent has representation agreements with top-level international companies specialized in water-treatment systems for the provision of these units.
