Carbodiimide coatings prepared from isocyanates supplied by BASF enhance the performance of different substrates in various applications compared to the raw or uncoated substrate, and compared alternative resin systems. An example of an application is the use of coated sand as a proppant for hydraulic fracturing.
Hydraulic fracturing is the process of creating fractures in a rock layer (shale layer), using a fluid as the source of energy to provide flow channels for natural gas and oil extraction. Fluid containing a proppant such as coated sand is injected under high pressure until the desired level of fracturing is achieved. The pressure is then released allowing the fluid to return to the well. The proppant, however, remains in the fractures, preventing them from closing.
Our patented carbodiimide encapsulation technology for proppants comprises of two components, both liquids, that combine to create a performance enhancing coating on sand particles. Traditional coatings based on phenolic resins utilize pastilles which make for additional processing steps as well as handling issues. In contrast, our all-liquid and non-formaldehyde technology offers shorter cycle times, reduction of scrap, and efficient processing. The fully cured coating features excellent thermal stability, acid resistance, crush resistance, and provides fracture conductivity performance comparable to conventional systems.