Experimental Investigation on the Influence of Proppant Crushing on the Propped Fracture Conductivity

Abstract

Hydraulic fracturing is a key stimulation technique for enhancing the productivity of tight sandstone reservoirs, with the conductivity of propped fractures serving as a critical parameter for evaluating stimulation effectiveness. This study investigated the conductivity behavior of propped fractures through laboratory experiments using commonly used oilfield proppants. The effects of proppant size, type, concentration, and proppant combination on fracture conductivity were systematically evaluated. Results show that at low closure stress, conductivity differences among various proppant types are negligible. However, under high closure stress, proppants with lower compressive strength exhibit significantly higher crushing rates, resulting in reduced conductivity compared to high-strength proppants. In mixtures of silica sand and ceramic proppant proppants, increasing the ceramic content lowers the overall crushing rate and mitigates conductivity degradation. Additionally, blending proppants of different sizes under high stress reduces breakage, with finer particles contributing to this effect. Higher proppant concentrations also lead to lower crushing rates and improved fracture conductivity. This work provides valuable insights into optimizing proppant selection and design for reservoir stimulation and oil and gas recovery.