Class 021
Houseware and Glass Products
Materials for sensing geometries of propped fractures in subterranean formations; materials for identifying locations of proppants in subterranean formations; tracers; materials for sensing flow back of proppants in subterranean formations; materials capable of indicating changes of proppant placement dynamically over time
Class 040
Treatment & Processing of Materials Services
Chemical for use as a fluid loss additive employed to minimize fluid losses in subterranean formations; chemical agents for use in treatment, servicing, and working of oil wells and gas wells, namely, subterranean formation filling agents, proppants, and abrasive agents for subterranean formations
