ClearWELL™ is a surface mounted, electromagnetic signaling technology which provides long-term, continuous protection from scale deposition in oil and gas wells and surface processing facilities.
ClearWELL™ is highly effective in preventing the deposition of calcium carbonate, barium sulphate, calcium sulphate, strontium sulphate and halite.
ClearWELL™ is connected to the surface equipment without interrupting production and transmits a pulsed radio frequency signal along the tubing via a metal-to-metal connection. ClearWELL™ has low power consumption, which can be provided via solar power, and the performance of the ClearWELL™ can be monitored remotely. The technology is safe, environmentally friendly and has the potential to save millions of dollars in scale remediation and lost production each year.
How does scale form?
Scale formation occurs when dissolved solids that are present in produced water become supersaturated. Supersaturation typically occurs due to changes in conditions such as temperature and pressure or due to the mixing of incompatible waters such as formation water rich in Ca2+ and Ba2+ and sea water rich in sulphate (SO42-). The formation of scale and its deposition on a surface follows the steps shown in the image opposite.
When a solution becomes supersaturated nucleation will begin to occur. The process of nucleation is usually described as heterogenous or homogenous nucleation. Homogenous nucleation occurs in the absence of any foreign particle or surface. Heterogenous nucleation is the formation of nuclei due to the presence of a foreign particle or imperfect surface that allows the adsorption of the crystal material on its surface. Heterogenous nucleation is the most common form of nucleation as it requires less energy than homogenous nucleation and can occur at lower saturation levels. Secondary nucleation then occurs as a result of the crystal surfaces that are already present and this is the crystal growth stage. Adherence typically occurs in tandem with crystal growth as part of the heterogenous nucleation process.
How does ClearWELL™ work?
ClearWELL™ technology imparts an electromagnetic field (EMF) signal into the produced fluid, which has sufficient energy to promote homogenous nucleation before heterogenous nucleation and crystal growth and adherence can occur.
The result is the formation of many non-adhesive, microscopic crystal particles, which are carried out of the well within the bulk fluid.
Independently peer-reviewed studies provide evidence for the effect and efficacy of the technology:
- SPE-170898 Preventing scale deposition downhole using high frequency electromagnetic AC signals from surface to enhance production offshore Denmark (2014): https://doi.org/10.2118/170898-MS
- SPE-169415-MS An environmentally friendly method to control halite scale deposition: Proved case histories from Latin America (2014): https://doi.org/10.2118/169415-MS
- SPE-133526-PP Physical water treatment in the oilfield (2014): https://doi.org/10.2118/133526-MS
- SPE-114072 Two-year results of a breakthrough physical water treating system for the control of scale in oilfield applications (2008): https://doi.org/10.2118/114072-MS
Features and Benefits
How does ClearWell™ add value?
ClearWELL™ is suitable for onshore and offshore wells, plus topside processing facilities and adds value to your operations because it:
- Offers continuous life-time protection.
- Has a small wellsite footprint.
- Requires no well intervention or production loss during installation.
- Vastly reduces or eliminates scale remediation operations and production loss over the life of a well.
- Lowers the carbon footprint of the asset by reducing or eliminating scale remediation operations and the transportation of personnel, equipment and bulk chemicals.
- Improves integrity and safety, protecting all tubing and downhole equipment that is exposed to the produced fluids including safety valves, progressing cavity pumps (PCPs) and electrical submersible pumps (ESPs).
- Saves costly retrieval and replacement of failed equipment.
- Provides a solution where the use of chemical inhibitors is difficult:
- Absence of downhole injection
- Environmental regulatory restrictions
- Variable produced water rates
- HTHP wells
- Remote wells or unmanned facilities
- Can be monitored remotely via a satellite enabled live link.
- Is high quality, durable and robust, designed and manufactured under ISO 9001 certified systems. It has low power consumption and is supplied as a certified Class 1, Zone 1 model as standard, and available for use in hazardous areas (zone 1 and 2) with full ATEX/IECEx certification.
Zero Carbon Footprint
By continuously preventing scale build-up in the well and on downhole equipment, such as pumps and valves, ClearWELL™ can reduce or eliminate:
- Remedial well intervention operations to treat scale build-up.
- Lost production related to remedial well intervention.
- Lost production related to reduced flow over time.
- Travel and shipping costs for personnel, equipment and chemicals employed in traditional remedial work plus the related carbon footprint.
- Use of chemicals.
- Costly retrieval and replacement of downhole equipment damaged by scale e.g., ESPs.
- HSE risk through reduced personnel, logistics, onsite operations, equipment and chemical handling.
- The offshore deck space or wellsite footprint requirement for remedial intervention equipment and operations.