Sustainable Solution for Oil Well Cementing: Investigating Fiberglass as a Strength-Enhancing Additive

ABSTRACT: In oil and gas drilling, well cementing operation is required to achieve the wellbore integrity, zonal isolation and permanent wellbore plugging. To maintain cement performance under varying environmental conditions, additives are mixed into the cement slurry. Fiberglass is widely used in industries such as renewable, construction and electronics; however, its disposal - especially from decommissioned wind turbine blades - poses environmental challenges. This study investigates the potential of repurposing milled fiber (E-Glass and I-Glass) as an additive to enhance the mechanical properties of wellbore cement. The cement slurry was formulated and modified with three different concentrations of fiberglass 3%, 6%, and 9% By Weight of Cement (BWOC). Cylindrical core samples were cast and subsequently tested for compressive and tensile strength performance. Digital image correlation techniques were employed to capture displacement and strain fields, microcrack development, crack initiation and propagation. Results indicate that incorporating fiberglass significantly increases both compressive and tensile strengths -fourfold increase in performance relative to Portland cement. Enhanced crack control was also observed, indicating improved durability under mechanical loading. Overall, these findings suggest that milled fiberglass can be effectively utilized to improve wellbore cement properties, offering a sustainable alternative that mitigates environmental risks associated with conventional disposal practices.