Hydrothermal Synthesis of Zeolites in Porous Media

Abstract

In hydraulic fracturing, pressurized aqueous solutions are used to fracture shale rock, and increase its permeability, enabling access to trapped deposits of natural gas. Currently, micron-sized proppants are used to prevent the induced hydraulic fractures from closing after the applied pressure is released. However these micron-sized proppants are unable to prevent the nanosized fractures from closing. Zeolites are a promising class of compounds to serve as nanoproppants due to their low framework density and the possibility of forming them in situ using reactants from the surrounding shale rock. In investigating the use of zeolites as nanoproppants, this research aims to investigate the feasibility of synthesizing zeolites in the micron-sized and nanosized pores of a polyethersulfone membrane, at the conditions typical of hydraulic fracturing, via hydrothermal confined-space synthesis. The use of such low-density nanoproppants promises to reduce proppant-pumping costs and extend well lifetimes. The findings of the study show the formation of aluminosilicate precipitates within the micron-sized support layer of the polymer membrane used and suggest the formation of aluminosilicate precipitates within the nanoporous membrane layer.