The ClearWELL system attacks scale deposition from a different angle, by controlling the size of crystals and where they form. The device sends an alternating current (AC) electromagnetic signal through a conductive path-the pipe and production equipment itself.
"The piping acts as an antenna and a transmission line for the AC signal, which propagates throughout the system," explains Parker. 'This signal does not interfere with the pipeline's cathodic protection system."
The charged ions in the saturated aqueous phase respond to this electromagnetic signal by absorbing energy and migrating to form areas of slightly higher concentration. Homogeneous nucleation begins at these more concentrated regions, and small crystallites form in the fluid phase, rather than at the pipe wall.
"Because the ClearWELL system uses the entire piping network as the conduit, the effect of the electromagnetic field is delocalized across the system," says Parker. "This delocalization, combined with the relatively high 120-kilohertz frequency of the AC signal, ensures that a large number of tiny nucleation sites are created."
The small crystals remain suspended in the fluid and exit the system without collecting on the pipe and production equipment internals. "While it is true that these crystals settle out eventually, it is far easier to deal with them at the surface rather than inside the wellbore," adds Parker.
The ClearWELL system's physical approach to water treatment provides environmentally sustainable benefits. No chemicals are added to the wellbore in this treatment, ensuring that any material that comes out of the water was already present in the formation.
The system is easily installed at the surface to treat the entire wellbore and flowlines; and it can be powered by local sources (90 to 220 volts) or by solar technology, which is an advantage in remote locations. In addition, its Class 1, Zone 1 rating makes the ClearWELL system an extremely safe scale-control option.
