Ionic liquids as clay stabilizer additive in fracturing fluid

Abstract

Swelling clays in hydrocarbon-bearing rocks' mineralogy pose several challenges in developing unconventional hydrocarbon reservoirs, including permeability impairment and fracture network retardation. Different clay stabilizers are incorporated in fracturing fluids to help solve this challenge. The effect of clay swelling on the compressive strength of rock was studied using unconfined compression and scratch tests. Also, the tensile strength of rocks exposed to different clay stabilizers was tested using a Brazilian disc test and a breakdown pressure experiment. A medical CT scan of the tested samples was thoroughly studied to inspect the propagation and distribution of the fractures during breakdown pressure experiments. The results revealed that, in comparison to the base scenario, where water was utilized as the fracturing fluid, the clay stabilizers reduced clay swelling and decreased compressive strength. A higher reduction in breakdown pressure and tensile strength was noticed in ionic liquid-based fracturing fluid compared to those treated with tested organic salt. Moreover, the presence and growth of a fracture network were confirmed by medical CT images.