Polymers for proppants used in hydraulic fracturing

Fracturing has been the one of the major contributors in increasing the flow of oil or gas from the formation to the wellbore. Polymers have played a major role in the success of the fracturing process. It has been used as viscosity modifier of the drilling fluid and as coating to proppant sands. Coating the proppants with polymer not only improves its mechanical property, but also prevents the proppant flowback, reduces the generated proppant fines, and contains the loose proppant fines, which can reduce the oil or gas conductivity. Currently, there are a number of polymer coating systems available in the market and choosing which one to use can be a very tricky job. This review article aims to provide an overview on the polymer systems (organic, inorganic, and composite) currently used as proppant coating, and discuss the current research efforts and patents on the field.